Bootstrap error label

bootstrap error label

import Button from 'react-bootstrap/Button'; Label>.

Consider: Bootstrap error label

Error 017 samp
Hp 49.ff01 service error
1C8.2 CANT START DRIVER - ERROR 2
LINUX ERROR LOADING OPERATION SYSTEM

Bootstrap error label - you the

Validation(バリデーション)

現在、クライアントサイドのカスタム検証スタイルとツールチップは、支援技術に公開されていないため、アクセスできないことを認識しています。解決策を検討している間は、サーバーサイドのオプションを使用するか、ブラウザのデフォルトの検証方法を使用することをお勧めします。

How it works

フォーム検証がどのように機能するかを次に示します。

  • HTML フォームの検証は、CSS の 2 つの疑似クラス とを介して適用されます。 これは、 、 、および 要素に適用されます。
  • ブートストラップは、 および スタイルのスコープを親の クラスにスコープ指定し、通常は に適用されます。それ以外の場合、値のない必須フィールドはページの読み込み時に無効として表示されます。 このようにして、いつアクティブ化するかを選択できます(通常はフォームの送信が試行された後)。
  • フォームの外観をリセットするには(たとえば、AJAX を使用した動的フォーム送信の場合)、送信後に から クラスを削除します。
  • フォールバックとして、server-side validation の疑似クラスの代わりに、 と を使用できます。親クラスは必要ありません。
  • CSS の動作には制約があるため、(現在のところ)カスタム JavaScript を使用しないと、DOM のフォームコントロールの前にある にスタイルを適用できません。
  • モダンブラウザでは constraint validation API をサポートしています。フォームコントロールを検証するための一連の JavaScript メソッドです。
  • フィードバックメッセージは、browser defaults (ブラウザごとに異なり、CSS でスタイル設定できない) または追加の HTML と CSS を使用したカスタムフィードバックスタイルを利用できます。
  • JavaScript では、 を使用してカスタムの有効性メッセージを提供できます。

カスタムフォーム検証スタイル、オプションのサーバー側クラス、およびブラウザーのデフォルトについて、以下のデモを検討してください。

Custom styles

フォーム検証メッセージの場合、 ブール属性をに追加する必要があります。これにより、ブラウザのデフォルトのフィードバックツールチップが無効になりますが、JavaScript の form validation APIs へのアクセスは引き続き提供されます。 以下のフォームを送信してみてください。 JavaScript が送信ボタンをインターセプトし、フィードバックを中継します。 送信しようとすると、フォームコントロールに適用された およびスタイルが表示されます。

カスタムフィードバックスタイルは、フィードバックをより良く伝えるために、カスタムカラー、ボーダー、フォーカススタイル、アイコンを適用します。 のアイコンは でのみ利用可能であり、 では利用できません。

Browser defaults

カスタムバリデーションのフィードバックメッセージや、フォームの動作を変更するための JavaScript の記述はブラウザのデフォルト設定を使用することができます。下記のフォームを送信してみてください。お使いのブラウザや OS によって、フィードバックのスタイルが若干異なります。

これらのフィードバックスタイルは CSS ではスタイリングできませんが、JavaScript を使ってフィードバックテキストをカスタマイズすることができます。

クライアントサイドのバリデーションを使用することを推奨しますが、サーバーサイドのバリデーションが必要な場合には、とを使用して、無効なフォームフィールドと有効なフォームフィールドを示すことができます。これらのクラスでは もサポートされていることに注意してください。

無効なフィールドに対しては、無効なフィードバック/エラーメッセージが を使用して関連するフォームフィールドに関連付けられていることを確認してください (フィールドが既に追加のフォームテキストを指している場合には、この属性で複数の を参照することができることに注意してください)。

issues with border radiiを修正するために、入力グループは追加の クラスを必要とします。

Supported elements

バリデーションスタイルは、以下のフォームコントロールとコンポーネントで利用できます。

  • を使用したおよび(入力グループ内に 1 つまでのを含む
  • の との併用

Tooltips

フォームレイアウトが許すのであれば、 を と入れ替えて、スタイル付きのツールチップにバリデーションのフィードバックを表示させることができます。ツールチップの位置を決めるためには、 を持つ親を持つようにしてください。下の例では、カラムクラスはすでにこれを持っていますが、あなたのプロジェクトでは別の設定が必要になるかもしれません。

Sass

Variables

Mixins

2 つの mixin をloopを介して組み合わせ、フォーム検証のフィードバックスタイルを生成しています。

Map

これは、の検証用 Sass マップです。これを上書きしたり拡張したりして、異なる状態や追加の状態を生成することができます。

のマップには、ツールチップやフォーカススタイルをオーバーライドするための 3 つのオプションパラメータを含めることができます。

Loop

検証スタイルを生成するために、マップの値を繰り返し処理するために使用します。上記の Sass マップに変更があった場合は、このループを介してコンパイルされた CSS に反映されます。

Customizing

バリデーションの状態は、Sass の マップを使ってカスタマイズすることができます。この Sass マップは ファイルにあり、デフォルトの / の検証状態を生成します。このマップには、各状態の色、アイコン、ツールチップの色、フォーカスシャドウをカスタマイズするためのネストされたマップが含まれています。ブラウザでは他の状態はサポートされていませんが、カスタムスタイルを使用することで、より複雑なフォームフィードバックを簡単に追加することができます。

なお、 の値をカスタマイズする際には、 mixin を変更しないことをお勧めします。

Bootstrap Forms Validation

Bootstrap Forms Validation

Introduction to Bootstrap Forms Validation

Validation is used to form acceptance with some rules and regulations. Bootstrap has many classes to build a form. But validation requires for control data about form. In this topic, we are going to learn about the types of Bootstrap Form Validation. For example, the form has a password. Password has many rules according to requirements.

Someone needs letters, many need numeric, otherwise, somebody required any special characters. The user knows the fulfillment of the requirement, validation is important. Sometimes the user does not get the exact requirement of form or how much required to fulfill, that time validation is helpful to submit data correctly. If you do not fulfill the specification then you get the feedback in the form automatically.

How to Validate Forms with Bootstrap?

  • The bootstrap form makes validation overcome all complications of JavaScript coding and work easily with classes.
  • Three bootstrap form validation comes with some glyphicon to get the message of error, warning, and success. Validation classes always placed in the parent class.
  • Along with validation classes, it also requires the has-feedback class to get the icon in the proper place in the form input box along with the label. This class placed in the parent class.

Example:

Code:

The form-control-feedback class was also necessary with the glyphicon icon to set icon in the box of the input form.

Example:

Code:

Types of Bootstrap Forms Validation

There are 3 types of bootstrap form as mentioned below:

1. has-success

This class used to get the message of success. With this validation class, users need also “glyphicon glyphicon-ok” icon to show the icon of success. If the user enters the input in the form correctly then this validation worked.

The has-success class comes up with a parent class. To get the success message to use this validation used. The below example gives the horizontal form format. Output comes with the message in the green color.

Syntax:

Example:

Code:

Output:

Bootstrap Forms Validation Output 1

2. has-warning

This class used for warning messages of form input. With this validation class, users need also a “glyphicon glyphicon- warning-sign” icon to show the icon of warning. If we enter the wrong input in the form, we have one more chance to enter input that time warning validation worked.

Warning validation class placed in parent class with a has-feedback class. If the user gets the warning of some kind of mistake then this class worked. The outcome comes with the message in yellow color.

Syntax:

Example:

Code:

Output:

Bootstrap Forms Validation Output 2

3. has-error

This class used for error message of form input. With this validation class, users need also “glyphicon glyphicon-remove” icon to show the icon of error. If we enter the wrong input in the form, this validation worked.

Error validation class placed in parent class with a has-feedback class. If the user gets the error message of mistake then this class worked.

Syntax:

Example:

Code:

Output:

Bootstrap Forms Validation Output 3

Explanation:

  •  All form is a horizontal layout. The label has 2 columns and input has 10 columns. Validation class set with has-feedback into parent div. To see the icon user used glyphicon icons with form-control-feedback in the <span>
  • Users work on the password. either password is correct then success validation work or password is wrong then error validation work. If the password has some mistake and we can able to recorrect then warning validation work.

Examples of Bootstrap Forms Validation

Below are the different examples of bootstrap forms validation:

Example #1

The following example is Validation with the horizontal form. Glyphicon sign is work on the inner input box in the form. Label and input in one horizontal line but all form-group class is vertically placed.

Code:

Output:

Output 4

Example #2

The following example is Validation with the vertical form. In the vertical form, all labels and inputs are vertical situated. Glyphicon can be situated in the line of the label at the end of the input box.

There is no class in the form. It is rarely used in form validation in bootstrap.

Code:

Output:

Output 5

Example #3

The following example is Validation with the inline form. The inline form has all labels and input in one line including all form groups. This is a complicated but validation icon placed in the input box of the form.

If users need only small form and login form then with validations then the inline form can apply.

Code:

Output:

Output 6

Above all example has all validation type with all layout and how it works. As per user requirement and easiness choose the format of form validation and layout.

Conclusion

Mostly form validation occurs on the server-side to control data of form in a database. For those purposes, we get many complicated coding and using the validation method using JavaScript language. Bootstrap did all things in one form page avoiding complications and lengthy coding and control the form data effortlessly.

Recommended Articles

This is a guide to Bootstrap Form Validation. Here we discuss the basic concept, 3 types of bootstrap forms validation along with the appropriate examples. You may also look at the following articles to learn more –

  1. What is Bootstrap?
  2. Bootstrap Commands
  3. Bootstrap Form Layout
  4. Bootstrap Collapse

React Bootstrap Form Validation

Bootstrap vs React Bootstrap

First, let’s quickly discuss the difference between Bootstrap and React Bootstrap. Bootstrap is one of the oldest and most-used CSS libraries for Javascript. It was launched by Twitter in 2009 and gets downloaded close to 2.5 million times every week.

Bootstrap was never intended to be used with React—React hadn’t even been created when Bootstrap launched. While it’s a powerful JavaScript library, Bootstrap doesn’t play well with React. The problem is that under the hood, Bootstrap relies heavily on JQuery to manipulate the DOM, while React uses a virtual DOM to make changes. Any changes that are applied to the DOM with Bootstrap via JQuery do not get picked up by React.

React Bootstrap eliminates the reliance on JQuery and packages all of Bootstrap’s native components into pure React components. These components, along with Bootstrap's existing CSS styling and templates, can be imported as React components into a React project. 

Getting Started

To get started with form validation, we’ll spin up a React app using Create React App and install both Bootstrap and React Bootstrap into the project.

Once the dependencies are installed, start up the app

and head to http://localhost:3000 to check that the app is running.

Great! We’re ready to start coding. Open up the project in your favorite editor (VS Code is a good choice) and import the Bootstrap stylesheet. This will allow us to use Bootstrap classes on our components and elements. You can also remove the boilerplate code from App.js. 

Once our email form validation component is complete, we’ll import it into this file and render it between the divs.

Building the Form Component

Create a new file called EmailForm.js next to App.js inside src. This is the file where we’ll write all our form validation logic and render the email form component. 

Inside the file, import the Form component and the Button component. Create a top-level React component called EmailForm and render the Form component inside.

Let’s break this down.

The Form component wraps the whole form and allows us to access its children through dot notation. The Form Group wraps separate parts of the form. In this case, we only have one part: the email input. The Form Label allows us to give a label to the form.

The main piece of logic here is the Form Control. By telling this component that we are expecting a type of “email” we have already told React Bootstrap enough to provide us with some basic form validation. We’ll see how this validation works in a moment.

Because we’ve included the Button component inside the Form and given it a type of “submit,” React Bootstrap knows that this button needs to do form validation and form submission of the associated form when clicked.

As you can see, we’ve used some Bootstrap classes (d-flex flex-column align-items-center) on our outermost div to apply some basic styling. This styling comes from the stylesheet we imported in App.js.

Rendering the Form Component

Import your EmailForm component into App.js and render it between the divs

and head back to http://localhost:3000 to check out our newly rendered form

At this point, we'll get some basic email validation right out of the box. Try inputting an invalid email address into the input and hitting the “Submit Form” button.

React Bootstrap detected that the email address is missing an expected character, and rendered an error message.

Validating With AbstractAPI

That level of validation is great, but what if we want something a little more robust? A third-party validation API like AbstractAPI’s Free Email Validation API can tell us not only if an email is valid, but also give us some more useful information, like whether the address is currently deliverable and if the SMTP is valid, and a quality score for the email.

This tells us not only that the user’s input string contained all the expected characters for a properly formatted email, but also whether or not the email actually exists.

Let’s add a validation step to check the email input against AbstractAPI before we submit it.

Getting Started With the API

First, let’s get set up with an API key. You’ll need an API key to use any of AbstractAPI's endpoints. Each API requires a unique key, so even if you’ve used an AbstractAPI API before, you’ll need a new key for this one.

Navigate to the Email API homepage and click “Get Started.”

If you’ve never used Abstract before, you’ll be asked to create an account using your email and password. Don’t worry—you won’t be charged for anything. All of AbstractAPI’s endpoints are free to use for development.

Once you’ve created an account and logged in, you’ll land on the API homepage where you’ll see your API key, plus links to documentation, a sandbox for making test requests, and support information. 

Copy your API key. We’re going to use it in the next step.

Adding Custom Form Logic

Right now, Bootstrap is handling all of the form logic for us. In order to validate our email using AbstractAPI, we need to store the email somewhere in the state. We also need to add an onChange handler to update the state when a user inputs their email, and an onSubmit handler to perform the additional validation when the user clicks “Submit Form.”

Inside EmailForm.js, create a function called sendValidationRequest. This will handle taking the email our user has input.

In real life, the handleSubmitEmail handler would send the email to our backend. For the purposes of this tutorial, we’ll just log the email to the console.

Next, we need to add the validation step into our handleSubmitEmail function.

Sending the Validation Request

In order to validate the email with AbstractAPI, we first need to send the email to the API. To do that, we’ll need an HTTP client. React comes with the fetch client built-in, and it’s available as a global variable. The NPM packageaxiosis another easy-to-use alternative. For now, we’ll use fetch.

Next, create the URL where fetch will send the request. Per the AbstractAPI docs, the URL needs to include our API key and the email we want to validate.

Right now, we’re not including the email because we don’t know what it is yet. The email will be appended to the URL after the user inputs it, and before we send the request.

Create a function called sendEmailValidationRequest. This is where we’ll pull our email out of state and send it to the API for validation. 

The validationResponse will contain the JSON object that the AbstractAPI endpoint sends back.  Note that we’ve used await twice to access the JSON object inside the response: once to await the response from the network, and again to parse the response into JSON.

The JSON object will contain information about whether our email is valid, along with the other information. It should look something like this:

Let’s add the sendValidationRequest function as the first step in our handleSubmit function.

Next, we need to examine the API’s response and use it to determine whether we should submit the email or not.

Using the API Response in Form Validation

The most important part of the API JSON response is the is_valid_format object, which contains a boolean value field. This field will tell us whether or not the email is properly formatted. We only want to submit the email if this field is “true.”

Let’s return the value of this field from our sendValidationRequest function, and add some conditional logic to check the value of it inside handleSubmitEmail.

Great! We’ve successfully validated an email and used its validity to determine whether or not to send it to our database.

Next, we need to let the user know whether or not their email was valid. We can use React Bootstrap’s Form Control Feedback component to do this.

Rendering an Error Message

If the email is invalid, we need to let the user know. We’ll add a Feedback component with an error message in it if the is_valid_format.value response from the API comes back “false.”

First, we need to create a value in the state to hold our error message.

As you can see, we’re initializing the errors value to be an object instead of a string. Why? We might want to render multiple errors. We’ll talk more about this in a moment.

Next, render the Form Control Feedback component below the FormControl component.

This component will display feedback to the user only if the errors object has an email field that is not “null.” It will also render whatever string is present in the errors.email field. 

To hook it up to our email Form Control component, we need to utilize the isInvalid field on the Form Control.

Let’s add the logic to render the error message.

Here, if the response from the API indicates that the email was invalid, we add an email field to the errors object, and populate it with the error message we want to show our user. If the response was valid, we clear any email error that might have previously been shown and submit the email.

Head back to http://localhost:3000 and try to submit an invalid email.

Note: AbsctractAPI does some clever stuff with autocorrecting. If the user inputs an email like “[email protected]” for example, Abstract will autocorrect the email to “[email protected]” and return that the email was valid. 

Putting it All Together

Here’s what our EmailForm.js file should look like when all is said and done:

That’s all it takes to get a basic email validation form up and running with AbstractAPI.

Conclusion

There are still many things that can be improved upon here. 

For starters, we’re not handling errors that might arise from network failures (404, 500, etc.) or other issues that might come up when trying to send a request to the API endpoint.

Next, we could add a loading spinner when the user hits “Submit Form” and disable the “Submit Form” button to indicate to the user that something is happening, and prevent the user from clicking the button multiple times.

Finally, we could hook up the form validation function to be called in the onBlur handler so that the email gets validated before the user hits submit. We could also put it in the onChange handler if we wanted to validate at every keystroke (this would also require us to debounce the request.)

But for now, we’ve made a pretty good start on form validation for email!

FAQs

What is React Bootstrap?

React Bootstrap is a component library that bundles the styling and reusable components of Bootstrap into pure React components. It allows Bootstrap to seamlessly integrate with React’s virtual DOM, rather than relying on JQuery to make DOM updates.

What is the difference between Bootstrap and React Bootstrap?

Bootstrap is a JavaScript framework, released by Twitter in 2011. It is one of the most popular libraries for Javascript, with over 2.5 million downloads every week. Bootstrap is first and foremost a CSS framework that allows you to apply pre-defined classes to DOM elements and then organizes and styles those elements for you. It also exports some pre-made components that can be used inside your web app.

React Bootstrap takes Bootstrap’s pre-defined styles and bundles them into reusable React components. You can import these components into your app. Vanilla Bootstrap does not play well with React because of the use of JQuery, which manipulates the DOM. React relies on a shadow or virtual DOM to perform updates, so Bootstrap changes applied to the DOM are not picked up by React.

What is form validation?

Form validation is an important part of frontend web and mobile development. It is the process of ensuring that the input users have given you is correct and well-formatted. An email validation form, for example, checks that the provided email contains all the expected characters (like ‘@’ and ‘.com’) and that it doesn’t contain any unexpected characters or malicious scripts.

Form validation not only prevents your users from inputting the wrong information, it protects them and your system from attacks from bad actors.

Mark error in form using Bootstrap

(UPDATED with examples for Bootstrap v4, v3 and v3)

Examples of forms with validation classes for the past few major versions of Bootstrap.

Bootstrap v4

See the live version on codepen

bootstrap v4 form validation

Bootstrap v3

See the live version on codepen

bootstrap v3 form validation

Bootstrap v2

See the live version on jsfiddle

bootstrap v2 form validation

The , , and classes are appended to the . This is standard Bootstrap markup and styling in v2. Just follow that and you're in good shape. Of course you can go beyond with your own styles to add a popup or "inline flash" if you prefer, but if you follow Bootstrap convention and hang those validation classes on the it will stay consistent and easy to manage (at least since you'll continue to have the benefit of Bootstrap docs and examples)

Validation

import Button from'react-bootstrap/Button';

import Col from'react-bootstrap/Col';

import Form from'react-bootstrap/Form';

import InputGroup from'react-bootstrap/InputGroup';

import Row from'react-bootstrap/Row';

const{ Formik }= formik;

const schema = yup.object().shape({

firstName: yup.string().required(),

lastName: yup.string().required(),

username: yup.string().required(),

city: yup.string().required(),

state: yup.string().required(),

zip: yup.string().required(),

terms: yup.bool().required().oneOf([true],'Terms must be accepted'),

});

functionFormExample(){

return(

<Formik

validationSchema={schema}

onSubmit={console.log}

initialValues={{

firstName:'Mark',

lastName:'Otto',

username:'',

city:'',

state:'',

zip:'',

terms:false,

}}

>

{({

handleSubmit,

handleChange,

handleBlur,

values,

touched,

isValid,

errors,

})=>(

<FormnoValidateonSubmit={handleSubmit}>

<RowclassName="mb-3">

<Form.Groupas={Col}md="4"controlId="validationFormik01">

<Form.Label>First name</Form.Label>

<Form.Control

type="text"

name="firstName"

value={values.firstName}

onChange={handleChange}

isValid={touched.firstName &&!errors.firstName}

/>

<Form.Control.Feedback>Looks good!</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="4"controlId="validationFormik02">

<Form.Label>Last name</Form.Label>

<Form.Control

type="text"

name="lastName"

value={values.lastName}

onChange={handleChange}

isValid={touched.lastName &&!errors.lastName}

/>

<Form.Control.Feedback>Looks good!</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="4"controlId="validationFormikUsername">

<Form.Label>Username</Form.Label>

<InputGrouphasValidation>

<InputGroup.Textid="inputGroupPrepend">@</InputGroup.Text>

<Form.Control

type="text"

placeholder="Username"

aria-describedby="inputGroupPrepend"

name="username"

value={values.username}

onChange={handleChange}

isInvalid={!!errors.username}

/>

<Form.Control.Feedbacktype="invalid">

{errors.username}

</Form.Control.Feedback>

</InputGroup>

</Form.Group>

</Row>

<RowclassName="mb-3">

<Form.Groupas={Col}md="6"controlId="validationFormik03">

<Form.Label>City</Form.Label>

<Form.Control

type="text"

placeholder="City"

name="city"

value={values.city}

onChange={handleChange}

isInvalid={!!errors.city}

/>

<Form.Control.Feedbacktype="invalid">

{errors.city}

</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="3"controlId="validationFormik04">

<Form.Label>State</Form.Label>

<Form.Control

type="text"

placeholder="State"

name="state"

value={values.state}

onChange={handleChange}

isInvalid={!!errors.state}

/>

<Form.Control.Feedbacktype="invalid">

{errors.state}

</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="3"controlId="validationFormik05">

<Form.Label>Zip</Form.Label>

<Form.Control

type="text"

placeholder="Zip"

name="zip"

value={values.zip}

onChange={handleChange}

isInvalid={!!errors.zip}

/>

<Form.Control.Feedbacktype="invalid">

{errors.zip}

</Form.Control.Feedback>

</Form.Group>

</Row>

<Form.GroupclassName="mb-3">

<Form.Check

required

name="terms"

label="Agree to terms and conditions"

onChange={handleChange}

isInvalid={!!errors.terms}

feedback={errors.terms}

feedbackType="invalid"

id="validationFormik0"

/>

</Form.Group>

<Buttontype="submit">Submit form</Button>

</

Bootstrap error label - that interfere

<div class="container">

 

<h1>A demo of Bootstrap validate form</h1>

 

</div>

 

<!-- don't forget novalidate to stop browser form validation -->

 

<form class="form">

 

<div class="container">

 

<div class="row">

 

<div class='col-sm-4 form-group'>

 

<label for="name">Your Name:</label>

 

<input id="lname"class="form-control"min="3"requiredtype="text"data-error-msg="Must enter your name?">

 

</div>

 

<div class='col-sm-4 form-group'>

 

<label for="name">Email:</label>

 

<input id="email"class="form-control"type="email"requireddata-error-msg="The email is required in valid format!">

 

</div>

 

</div>

 

<div class='row'>

 

<div class='col-sm-4 form-group'>

 

<label for='address'>Address: (optional)</label>

 

<input id='address'class='form-control'type='text'>

 

</div>

 

</div>

 

<div class="row">

 

<div class='col-sm-4 form-group'>

 

<label for='terms'>Agree with T&Cs?</label>

 

<select id='terms'class='form-control'required>

 

<option selecteddisabled>Select </option>

 

<option value="Y">Yes</option>

 

<option value="N">No</option>

 

</select>

 

</div>

 

<div class='col-sm-4 form-group'>

 

<div class="checkbox">

 

<label>

 

<input type="checkbox"name="option1"value=""requireddata-error-msg="You have to select one expertise.">

 

                        HTML

 

</label>

 

</div>

 

<div class="checkbox disabled">

 

<label>

 

<input type="checkbox"name="option1"value="">

 

                        CSS

 

</label>

 

</div>

 

</div>

 

<div class='col-sm-4 form-group'>

 

<div class="radio">

 

<label>

 

<input type="radio"name="optionsRadios"id="optionsRadios1"value="option1">

 

                        Python

 

</label>

 

</div>

 

<div class="radio">

 

<label>

 

<input type="radio"name="optionsRadios"id="optionsRadios2"value="option2">

 

                        Java

 

</label>

 

</div>

 

<div class="radio disabled">

 

<label>

 

<input type="radio"name="optionsRadios"id="optionsRadios3"value="option3">

 

                        SQL

 

</label>

 

</div>

 

</div>

 

</div>

 

<div class="row">

 

<div class="col-sm-4 col-sm-offset-4">

 

<button type="submit"class="btn btn-danger btn-block">Proceed</button>

 

</div>

 

</div>

 

</div>

Bootstrap 5 Form Validation

❮ PreviousNext ❯


Form Validation

You can use different validation classes to provide valuable feedback to users. Add either or to the element, depending on whether you want to provide validation feedback before or after submitting the form. The input fields will have a green (valid) or red (invalid) border to indicate what's missing in the form. You can also add a or message to tell the user explicitly what's missing, or needs to be done before submitting the form.

Example

In this example, we use to indicate what's missing before submitting the form:

<form action="/action_page.php" class="was-validated">
  <div class="mb-3 mt-3">
    <label for="uname" class="form-label">Username:</label>
    <input type="text" class="form-control" id="uname" placeholder="Enter username" name="uname" required>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Please fill out this field.</div>
  </div>
  <div class="mb-3">
    <label for="pwd" class="form-label">Password:</label>
    <input type="password" class="form-control" id="pwd" placeholder="Enter password" name="pswd" required>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Please fill out this field.</div>
  </div>
  <div class="form-check mb-3">
    <input class="form-check-input" type="checkbox" id="myCheck" name="remember" required>
    <label class="form-check-label" for="myCheck">I agree on blabla.</label>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Check this checkbox to continue.</div>
  </div>
  <button type="submit" class="btn btn-primary">Submit</button>
</form>

Try it Yourself »

❮ PreviousNext ❯


Mark error in form using Bootstrap

(UPDATED with examples for Bootstrap v4, v3 and v3)

Examples of forms with validation classes for the past few major versions of Bootstrap.

Bootstrap v4

See the live version on codepen

bootstrap v4 form validation

Bootstrap v3

See the live version on codepen

bootstrap v3 form validation

Bootstrap v2

See the live version on jsfiddle

bootstrap v2 form validation

The , , and classes are appended to the . This is standard Bootstrap markup and styling in v2. Just follow that and you're in good shape. Of course you can go beyond with your own styles to add a popup or "inline flash" if you prefer, but if you follow Bootstrap convention and hang those validation classes on the it will stay consistent and easy to manage (at least since you'll continue to have the benefit of Bootstrap docs and examples)

Bootstrap CSS Classes for Styling Validation Messages

In the previous section, we applied AngularJS built-in CSS classes to a form. Here, we will apply bootstrap CSS classes for styling form field error, warning, or validity.

Bootstrap includes following CSS classes for the form validation.

Bootstrap CSS Class Description
has-error Set this CSS class when a form field becomes invalid based on applied validation attributes.
has-warning Set this CSS class to display warning for a form field.
has-success Set this CSS class when a form field becomes valid based on applied validation attributes.

The following is a student form with bootstrap validation classes.

In the above example, we have applied ng-class directive to each <div> element with CSS class name and an expression. If an expression evaluates to true then specified CSS class will be applied.

Validation(バリデーション)

現在、クライアントサイドのカスタム検証スタイルとツールチップは、支援技術に公開されていないため、アクセスできないことを認識しています。解決策を検討している間は、サーバーサイドのオプションを使用するか、ブラウザのデフォルトの検証方法を使用することをお勧めします。

How it works

フォーム検証がどのように機能するかを次に示します。

  • HTML フォームの検証は、CSS の 2 つの疑似クラス とを介して適用されます。 これは、 、 、および 要素に適用されます。
  • ブートストラップは、 および スタイルのスコープを親の クラスにスコープ指定し、通常は に適用されます。それ以外の場合、値のない必須フィールドはページの読み込み時に無効として表示されます。 このようにして、いつアクティブ化するかを選択できます(通常はフォームの送信が試行された後)。
  • フォームの外観をリセットするには(たとえば、AJAX を使用した動的フォーム送信の場合)、送信後に から クラスを削除します。
  • フォールバックとして、server-side validation の疑似クラスの代わりに、 と を使用できます。親クラスは必要ありません。
  • CSS の動作には制約があるため、(現在のところ)カスタム JavaScript を使用しないと、DOM のフォームコントロールの前にある にスタイルを適用できません。
  • モダンブラウザでは constraint validation API をサポートしています。フォームコントロールを検証するための一連の JavaScript メソッドです。
  • フィードバックメッセージは、browser defaults (ブラウザごとに異なり、CSS でスタイル設定できない) または追加の HTML と CSS を使用したカスタムフィードバックスタイルを利用できます。
  • JavaScript では、 を使用してカスタムの有効性メッセージを提供できます。

カスタムフォーム検証スタイル、オプションのサーバー側クラス、およびブラウザーのデフォルトについて、以下のデモを検討してください。

Custom styles

フォーム検証メッセージの場合、 ブール属性をに追加する必要があります。これにより、ブラウザのデフォルトのフィードバックツールチップが無効になりますが、JavaScript の form validation APIs へのアクセスは引き続き提供されます。 以下のフォームを送信してみてください。 JavaScript が送信ボタンをインターセプトし、フィードバックを中継します。 送信しようとすると、フォームコントロールに適用された およびスタイルが表示されます。

カスタムフィードバックスタイルは、フィードバックをより良く伝えるために、カスタムカラー、ボーダー、フォーカススタイル、アイコンを適用します。 のアイコンは でのみ利用可能であり、 では利用できません。

Browser defaults

カスタムバリデーションのフィードバックメッセージや、フォームの動作を変更するための JavaScript の記述はブラウザのデフォルト設定を使用することができます。下記のフォームを送信してみてください。お使いのブラウザや OS によって、フィードバックのスタイルが若干異なります。

これらのフィードバックスタイルは CSS ではスタイリングできませんが、JavaScript を使ってフィードバックテキストをカスタマイズすることができます。

クライアントサイドのバリデーションを使用することを推奨しますが、サーバーサイドのバリデーションが必要な場合には、とを使用して、無効なフォームフィールドと有効なフォームフィールドを示すことができます。これらのクラスでは もサポートされていることに注意してください。

無効なフィールドに対しては、無効なフィードバック/エラーメッセージが を使用して関連するフォームフィールドに関連付けられていることを確認してください (フィールドが既に追加のフォームテキストを指している場合には、この属性で複数の を参照することができることに注意してください)。

issues with border radiiを修正するために、入力グループは追加の クラスを必要とします。

Supported elements

バリデーションスタイルは、以下のフォームコントロールとコンポーネントで利用できます。

  • を使用したおよび(入力グループ内に 1 つまでのを含む
  • の との併用

Tooltips

フォームレイアウトが許すのであれば、 を と入れ替えて、スタイル付きのツールチップにバリデーションのフィードバックを表示させることができます。ツールチップの位置を決めるためには、 を持つ親を持つようにしてください。下の例では、カラムクラスはすでにこれを持っていますが、あなたのプロジェクトでは別の設定が必要になるかもしれません。

Sass

Variables

Mixins

2 つの mixin をloopを介して組み合わせ、フォーム検証のフィードバックスタイルを生成しています。

Map

これは、の検証用 Sass マップです。これを上書きしたり拡張したりして、異なる状態や追加の状態を生成することができます。

のマップには、ツールチップやフォーカススタイルをオーバーライドするための 3 つのオプションパラメータを含めることができます。

Loop

検証スタイルを生成するために、マップの値を繰り返し処理するために使用します。上記の Sass マップに変更があった場合は、このループを介してコンパイルされた CSS に反映されます。

Customizing

バリデーションの状態は、Sass の マップを使ってカスタマイズすることができます。この Sass マップは ファイルにあり、デフォルトの / の検証状態を生成します。このマップには、各状態の色、アイコン、ツールチップの色、フォーカスシャドウをカスタマイズするためのネストされたマップが含まれています。ブラウザでは他の状態はサポートされていませんが、カスタムスタイルを使用することで、より複雑なフォームフィードバックを簡単に追加することができます。

なお、 の値をカスタマイズする際には、 mixin を変更しないことをお勧めします。

Validation

import Button from'react-bootstrap/Button';

import Col from'react-bootstrap/Col';

import Form from'react-bootstrap/Form';

import InputGroup from'react-bootstrap/InputGroup';

import Row from'react-bootstrap/Row';

const{ Formik }= formik;

const schema = yup.object().shape({

firstName: yup.string().required(),

lastName: yup.string().required(),

username: yup.string().required(),

city: yup.string().required(),

state: yup.string().required(),

zip: yup.string().required(),

terms: yup.bool().required().oneOf([true],'Terms must be accepted'),

});

functionFormExample(){

return(

<Formik

validationSchema={schema}

onSubmit={console.log}

initialValues={{

firstName:'Mark',

lastName:'Otto',

username:'',

city:'',

state:'',

zip:'',

terms:false,

}}

>

{({

handleSubmit,

handleChange,

handleBlur,

values,

touched,

isValid,

errors,

})=>(

<FormnoValidateonSubmit={handleSubmit}>

<RowclassName="mb-3">

<Form.Groupas={Col}md="4"controlId="validationFormik01">

<Form.Label>First name</Form.Label>

<Form.Control

type="text"

name="firstName"

value={values.firstName}

onChange={handleChange}

isValid={touched.firstName &&!errors.firstName}

/>

<Form.Control.Feedback>Looks good!</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="4"controlId="validationFormik02">

<Form.Label>Last name</Form.Label>

<Form.Control

type="text"

name="lastName"

value={values.lastName}

onChange={handleChange}

isValid={touched.lastName &&!errors.lastName}

/>

<Form.Control.Feedback>Looks good!</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="4"controlId="validationFormikUsername">

<Form.Label>Username</Form.Label>

<InputGrouphasValidation>

<InputGroup.Textid="inputGroupPrepend">@</InputGroup.Text>

<Form.Control

type="text"

placeholder="Username"

aria-describedby="inputGroupPrepend"

name="username"

value={values.username}

onChange={handleChange}

isInvalid={!!errors.username}

/>

<Form.Control.Feedbacktype="invalid">

{errors.username}

</Form.Control.Feedback>

</InputGroup>

</Form.Group>

</Row>

<RowclassName="mb-3">

<Form.Groupas={Col}md="6"controlId="validationFormik03">

<Form.Label>City</Form.Label>

<Form.Control

type="text"

placeholder="City"

name="city"

value={values.city}

onChange={handleChange}

isInvalid={!!errors.city}

/>

<Form.Control.Feedbacktype="invalid">

{errors.city}

</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="3"controlId="validationFormik04">

<Form.Label>State</Form.Label>

<Form.Control

type="text"

placeholder="State"

name="state"

value={values.state}

onChange={handleChange}

isInvalid={!!errors.state}

/>

<Form.Control.Feedbacktype="invalid">

{errors.state}

</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="3"controlId="validationFormik05">

<Form.Label>Zip</Form.Label>

<Form.Control

type="text"

placeholder="Zip"

name="zip"

value={values.zip}

onChange={handleChange}

isInvalid={!!errors.zip}

/>

<Form.Control.Feedbacktype="invalid">

{errors.zip}

</Form.Control.Feedback>

</Form.Group>

</Row>

<Form.GroupclassName="mb-3">

<Form.Check

required

name="terms"

label="Agree to terms and conditions"

onChange={handleChange}

isInvalid={!!errors.terms}

feedback={errors.terms}

feedbackType="invalid"

id="validationFormik0"

/>

</Form.Group>

<Buttontype="submit">Submit form</Button>

</

Further to my first post about using Bootstrap with React Forms, this post will show you how to add validation to your Bootstrap React form, and show any errors when the form is submitted. Intentionally this is kept as straightforward as possible and without using any additional packages, so that you can learn the most basic way to build and handle a Bootstrap form in React (using Hooks). I’ve also kept all the code in one file – once you’ve built this React Bootstrap form example, you may want to refactor this code and separate it into a reusable Form component but I think it’s useful to see all the code in one place to get an initial understanding of how each part works.

React Bootstrap form example – breaking it down

Breaking this down into steps we will need to:

– Update the form fields to ‘useState’
– Check and validate the data that has been entered
– If there are problems with the data – stop the submission and display error messages
– If the data is OK – handle the onClick event of the submit button and submit the form

We’ll start by simplifying the form from part 1 so that we are left with only 2 form fields – name and email. Here is the starting code for the form. This has two fields and a submit button but if you click the submit button in this starting code it won’t do anything. Step by step we will add each part of the code needed to turn it into a fully functioning form.

import React, { useState } from "react"; import "bootstrap/dist/css/bootstrap.min.css"; import Container from "react-bootstrap/Container"; import Row from "react-bootstrap/Row"; import Col from "react-bootstrap/Col"; import Button from "react-bootstrap/Button"; import Form from "react-bootstrap/Form"; import Alert from "react-bootstrap/Alert"; import "./App.css"; function App() { const [showMessage, setShowMessage] = useState(false); return ( <div className="App"> <header className="App-header"> <p> React Bootstrap <code>Form Example</code>. </p> </header> <Container className="p-3"> <Container> <Row> <Col> <Alert show={showMessage} variant="success"> <Alert.Heading>Success</Alert.Heading> <p> Thanks for the message! </p> <hr /> <div className="d-flex justify-content-end"> <Button onClick={() => setShowMessage(false)} variant="outline-success" > Close this alert </Button> </div> </Alert> </Col> </Row> <Row> <Col></Col> <Col> <Form> <Form.Group controlId="formGridName"> <Form.Label>Name</Form.Label> <Form.Control placeholder="Full Name" type="text" name="fullname" /> </Form.Group> <Form.Row> <Form.Group as={Col} controlId="formGridEmail"> <Form.Label>Email</Form.Label> <Form.Control placeholder="Enter email" type="email" name="email" /> </Form.Group> </Form.Row> <Button type="submit" variant="primary" size="lg"> Submit </Button> </Form> </Col> <Col></Col> </Row> </Container> </Container> </div> ); } export default App;

Preserving form field values

First of all we will define a state variable called ‘values’. This will hold the value for each form field and will preserve it between function calls. To define it, and initialise each value within it, type this:

const [values, setValues] = useState({ fullname: "", email: "", });

This defines two items within the values object called fullname and email, and sets each to have a starting value of an empty string. Then we’ll define another state variable to hold the all the error information for each field – this is defining an empty object:

const [formerrors, setFormErrors] = useState({});

Next we need to make some changes to each form field so that we can start to use the form fields to set the data, so add type, name, and value properties to each of the form fields as follows, along with assigning a method called handleChange to the ‘onChange’ property of each form field:

<Form.Control placeholder="Full Name" type="text" name="fullname" value={values.fullname} onChange={handleChange} /> <Form.Control placeholder="Enter email" type="email" name="email" value={values.email} onChange={handleChange} />

And now we add the code for the handleChange method:

const handleChange = (event) => { //this console.log message should be removed once you've tested the event works console.log( "handleChange -> " + event.target.name + " : " + event.target.value ); //this is the important bit setValues((values) => ({ ...values, [event.target.name]: event.target.value, })); };

I like to use console.log messages to understand what’s happening when I’m learning something new. If you run the code once you’ve added that handler you’ll see the handleChange event fire every time you perform a keypress, something like this, where in the Developer tools console window you see the message develop:

React bootstrap handle change event

The main bit of code in the handle change event is updating the values object, by setting a property called ‘fullname’ and updating it’s value on every keystroke.

Check and validate Bootstrap React form data

Now we need to check the data that’s been entered into the form, so we’ll add a method called validateForm to our code like this, just after the handleSubmit method:

const validateForm = () => { // }

Next update the validate method so that it checks each form field according to rules that you will write. So for the email field we want to make sure that it is not empty and also that it is formatted according to standard email address rules. The name field we just want to check that it’s not empty. If any of these conditions are not met then we will populate the errors object with a message for the relevant field. When I’m building a form I also like to add a console.log message to each method before I fill it with code, just to check that the right methods are being called at the right time. These log messages show up in the Console window of the Chrome Developer tools. Here is the code for the validate function:

const validate = () => { console.log("Validate the form...."); let errors = {}; //name field if (!values.fullname) { errors.fullname = "Full name is required"; } //email field if (!values.email) { errors.email = "Email address is required"; } else if (!/\[email protected]\S+\.\S+/.test(values.email)) { errors.email = "Email address is invalid"; } setFormErrors(errors); if (Object.keys(errors).length === 0) { return true; } else { return false; } };

Displaying the error messages

If there are problems with any of the data we want to show the user what is wrong. And prefereably we want to show each error message against the form it relates to. So we add a small paragraph under each field which will only show up if there is an error for that field. Like this:

<Form.Control placeholder="Full Name" type="text" name="fullname" value={values.fullname} onChange={handleChange} required /> //error message - if formerrors.name contains a value, then show this message {formerrors.fullname && ( <p className="text-danger">{formerrors.fullname}</p> )}

If you run this now and test it, you’ll see the error message but it will just look like normal text. So we need to add a class to our markup to style the error messages. Bootstrap has some predefined colour classes which help convey meaning.

….. and now it will be red. Now change ‘text-danger‘ to ‘text-warning‘ and you’ll see it’s orange. All the colour utility classes are defined here.

React form submit – handling the event

We’ll add a function to handle the onClick event of the Submit button next. First of all add the method, and call it handleSubmit.

const handleSubmit = () => { if (event) event.preventDefault(); if (validate(values)) { setShowMessage(true); } else { setShowMessage(false); } }

This prevents the initial form reload, then calls the validate function, which returns a ‘true’ or a ‘false’. If it validates ok, and returns a true, then we call setShowMessage(true) which updates the showMessage value to ‘true’ and therefore displays the green success Bootstrap alert message.

And then we need to tell the Form to use this method when the Submit button is clicked, and to do this we have to modify the Form opening tag so that it looks like this:

<Form onSubmit={handleSubmit}>

We also need to specify that the Submit button is of the type Submit, in order for it to trigger the event to submit the Bootstrap React form. So change the button definition to this:

<Button type="submit" variant="primary" size="lg"> Submit </Button>

Save your changes, and now using the Chrome Developer Tools put a breakpoint in the App.js file in the handleSubmit method. Click the Submit button and the breakpoint should be hit – that tells you it’s all connected ok.

The working code

Here is the full code for the working form.

import React, { useState } from "react"; import "bootstrap/dist/css/bootstrap.min.css"; import Container from "react-bootstrap/Container"; import Row from "react-bootstrap/Row"; import Col from "react-bootstrap/Col"; import Button from "react-bootstrap/Button"; import Form from "react-bootstrap/Form"; import Alert from "react-bootstrap/Alert"; import "./App.css"; function App() { const [showMessage, setShowMessage] = useState(false); const [values, setValues] = useState({ fullname: "", email: "", }); const [formerrors, setFormErrors] = useState({}); //this method handles the each form field changing and updates the relevant //state value for that input const handleChange = (event) => { console.log( "handleChange -> " + event.target.name + " : " + event.target.value ); setValues((values) => ({ ...values, [event.target.name]: event.target.value, })); }; //this method will check each field in your form. You define //the rules for each field const validate = () => { console.log("Validate the form...."); let errors = {}; //name field if (!values.fullname) { errors.fullname = "Full name is required"; } //email field if (!values.email) { errors.email = "Email address is required"; } else if (!/\[email protected]\S+\.\S+/.test(values.email)) { errors.email = "Email address is invalid"; } setFormErrors(errors); if (Object.keys(errors).length === 0) { return true; } else { return false; } }; const handleSubmit = (event) => { if (event) event.preventDefault(); if (validate(values)) { setShowMessage(true); } else { setShowMessage(false); } }; return ( <div className="App"> <header className="App-header"> <p> React Bootstrap <code>Form Example</code>. </p> </header> <Container className="p-3"> <Container> <Row> <Col> <Alert show={showMessage} variant="success"> <Alert.Heading>Success</Alert.Heading> <p> This is an alert, and these can be shown in a variety of styles provided by Bootstrap. Our form submit button simply shows this alert. Another post will go through form validation and errors. </p> <hr /> <div className="d-flex justify-content-end"> <Button onClick={() => setShowMessage(false)} variant="outline-success" > Close this alert </Button> </div> </Alert> </Col> </Row> <Row> <Col></Col> <Col> <Form onSubmit={handleSubmit}> <Form.Group controlId="formGridName"> <Form.Label>Name</Form.Label> <Form.Control placeholder="Full Name" type="text" name="fullname" value={values.fullname} onChange={handleChange} /> {formerrors.fullname && ( <p className="text-warning">{formerrors.fullname}</p> )} </Form.Group> <Form.Row> <Form.Group as={Col} controlId="formGridEmail"> <Form.Label>Email</Form.Label> <Form.Control placeholder="Enter email" type="email" name="email" value={values.email} onChange={handleChange} /> {formerrors.email && ( <p className="text-warning">{formerrors.email}</p> )} </Form.Group> </Form.Row> <Button type="submit" variant="primary" size="lg" > Submit </Button> </Form> </Col> <Col></Col> </Row> </Container> </Container> </div> ); } export default App;

Summary

After reading both of these blog posts you should now have a simple working React Bootstrap form example with validation and error message handling. Be sure to read my post explaining how to use the React developer tools in Chrome to maximize your debugging skills.

<div class="container">

 

<h1>A demo of Bootstrap validate form</h1>

 

</div>

 

<!-- don't forget novalidate to stop browser form validation -->

 

<form class="form">

 

<div class="container">

 

<div class="row">

 

<div class='col-sm-4 form-group'>

 

<label for="name">Your Name:</label>

 

<input id="lname"class="form-control"min="3"requiredtype="text"data-error-msg="Must enter your name?">

 

</div>

 

<div class='col-sm-4 form-group'>

 

<label for="name">Email:</label>

 

<input id="email"class="form-control"type="email"requireddata-error-msg="The email is required in valid format!">

 

</div>

 

</div>

 

<div class='row'>

 

<div class='col-sm-4 form-group'>

 

<label for='address'>Address: (optional)</label>

 

<input id='address'class='form-control'type='text'>

 

</div>

 

</div>

 

<div class="row">

 

<div class='col-sm-4 form-group'>

 

<label for='terms'>Agree with T&Cs?</label>

 

<select id='terms'class='form-control'required>

 

<option selecteddisabled>Select </option>

 

<option value="Y">Yes</option>

 

<option value="N">No</option>

 

</select>

 

</div>

 

<div class='col-sm-4 form-group'>

 

<div class="checkbox">

 

<label>

 

<input type="checkbox"name="option1"value=""requireddata-error-msg="You have to select one expertise.">

 

                        HTML

 

</label>

 

</div>

 

<div class="checkbox disabled">

 

<label>

 

<input type="checkbox"name="option1"value="">

 

                        CSS

 

</label>

 

</div>

 

</div>

 

<div class='col-sm-4 form-group'>

 

<div class="radio">

 

<label>

 

<input type="radio"name="optionsRadios"id="optionsRadios1"value="option1">

 

                        Python

 

</label>

 

</div>

 

<div class="radio">

 

<label>

 

<input type="radio"name="optionsRadios"id="optionsRadios2"value="option2">

 

                        Java

 

</label>

 

</div>

 

<div class="radio disabled">

 

<label>

 

<input type="radio"name="optionsRadios"id="optionsRadios3"value="option3">

 

                        SQL

 

</label>

 

</div>

 

</div>

 

</div>

 

<div class="row">

 

<div class="col-sm-4 col-sm-offset-4">

 

<button type="submit"class="btn btn-danger btn-block">Proceed</button>

 

</div>

 

</div>

 

</div>

Validation(バリデーション)

現在、クライアントサイドのカスタム検証スタイルとツールチップは、支援技術に公開されていないため、アクセスできないことを認識しています。解決策を検討している間は、サーバーサイドのオプションを使用するか、ブラウザのデフォルトの検証方法を使用することをお勧めします。

How it works

フォーム検証がどのように機能するかを次に示します。

  • HTML フォームの検証は、CSS の 2 つの疑似クラス とを介して適用されます。 これは、 、 、および 要素に適用されます。
  • ブートストラップは、 および スタイルのスコープを親の クラスにスコープ指定し、通常は に適用されます。それ以外の場合、値のない必須フィールドはページの読み込み時に無効として表示されます。 このようにして、いつアクティブ化するかを選択できます(通常はフォームの送信が試行された後)。
  • フォームの外観をリセットするには(たとえば、AJAX を使用した動的フォーム送信の場合)、送信後に から クラスを削除します。
  • フォールバックとして、server-side validation の疑似クラスの代わりに、 と を使用できます。親クラスは必要ありません。
  • CSS の動作には制約があるため、(現在のところ)カスタム JavaScript を使用しないと、DOM のフォームコントロールの前にある にスタイルを適用できません。
  • モダンブラウザでは constraint validation API をサポートしています。フォームコントロールを検証するための一連の JavaScript メソッドです。
  • フィードバックメッセージは、browser defaults (ブラウザごとに異なり、CSS でスタイル設定できない) または追加の HTML と CSS を使用したカスタムフィードバックスタイルを利用できます。
  • JavaScript では、 を使用してカスタムの有効性メッセージを提供できます。

カスタムフォーム検証スタイル、オプションのサーバー側クラス、およびブラウザーのデフォルトについて、以下のデモを検討してください。

Custom styles

フォーム検証メッセージの場合、 ブール属性をに追加する必要があります。これにより、ブラウザのデフォルトのフィードバックツールチップが無効になりますが、JavaScript の form validation APIs へのアクセスは引き続き提供されます。 以下のフォームを送信してみてください。 JavaScript が送信ボタンをインターセプトし、フィードバックを中継します。 送信しようとすると、フォームコントロールに適用された およびスタイルが表示されます。

カスタムフィードバックスタイルは、フィードバックをより良く伝えるために、カスタムカラー、ボーダー、フォーカススタイル、アイコンを適用します。 のアイコンは でのみ利用可能であり、 では利用できません。

Browser defaults

カスタムバリデーションのフィードバックメッセージや、フォームの動作を変更するための JavaScript の記述はブラウザのデフォルト設定を使用することができます。下記のフォームを送信してみてください。お使いのブラウザや OS によって、フィードバックのスタイルが若干異なります。

これらのフィードバックスタイルは CSS ではスタイリングできませんが、JavaScript を使ってフィードバックテキストをカスタマイズすることができます。

クライアントサイドのバリデーションを使用することを推奨しますが、サーバーサイドのバリデーションが必要な場合には、とを使用して、無効なフォームフィールドと有効なフォームフィールドを示すことができます。これらのクラスでは もサポートされていることに注意してください。

無効なフィールドに対しては、無効なフィードバック/エラーメッセージが を使用して関連するフォームフィールドに関連付けられていることを確認してください (フィールドが既に追加のフォームテキストを指している場合には、この属性で複数の を参照することができることに注意してください)。

issues with border radiiを修正するために、入力グループは追加の クラスを必要とします。

Supported elements

バリデーションスタイルは、以下のフォームコントロールとコンポーネントで利用できます。

  • を使用したおよび(入力グループ内に 1 つまでのを含む
  • の との併用

Tooltips

フォームレイアウトが許すのであれば、 を と入れ替えて、スタイル付きのツールチップにバリデーションのフィードバックを表示させることができます。ツールチップの位置を決めるためには、 を持つ親を持つようにしてください。下の例では、カラムクラスはすでにこれを持っていますが、あなたのプロジェクトでは別の設定が必要になるかもしれません。

Sass

Variables

Mixins

2 つの mixin をloopを介して組み合わせ、フォーム検証のフィードバックスタイルを生成しています。

Map

これは、の検証用 Sass マップです。これを上書きしたり拡張したりして、異なる状態や追加の状態を生成することができます。

のマップには、ツールチップやフォーカススタイルをオーバーライドするための 3 つのオプションパラメータを含めることができます。

Loop

検証スタイルを生成するために、マップの値を繰り返し処理するために使用します。上記の Sass マップに変更があった場合は、このループを介してコンパイルされた CSS に反映されます。

Customizing

バリデーションの状態は、Sass の マップを使ってカスタマイズすることができます。この Sass マップは ファイルにあり、デフォルトの / の検証状態を生成します。このマップには、各状態の色、アイコン、ツールチップの色、フォーカスシャドウをカスタマイズするためのネストされたマップが含まれています。ブラウザでは他の状態はサポートされていませんが、カスタムスタイルを使用することで、より複雑なフォームフィードバックを簡単に追加することができます。

なお、 の値をカスタマイズする際には、 mixin を変更しないことをお勧めします。

Bootstrap Forms Validation

Bootstrap Forms Validation

Introduction to Bootstrap Forms Validation

Validation is used to form acceptance with some rules and regulations. Bootstrap has many classes to build a form, bootstrap error label. But validation requires for control data about form. In this topic, we are going to learn about the types of Bootstrap Form Validation. For example, bootstrap error label, the form has a password. Password has many rules according to requirements.

Someone needs letters, many need numeric, otherwise, somebody required any special characters. The user knows the fulfillment of the requirement, validation is important. Sometimes the user does not get the exact requirement of form or how much required to fulfill, that time validation is helpful to submit data correctly. If you do not fulfill the specification then you get the feedback in the form automatically.

How to Validate Forms with Bootstrap?

  • The bootstrap form makes validation overcome all complications of JavaScript coding and work easily with classes.
  • Three bootstrap form validation comes with some glyphicon to get the message of error, warning, and success. Validation classes always placed in the parent class.
  • Along with validation classes, it also requires the has-feedback class to get the icon in the proper place in the form input box along with the label. This class placed in the parent class.

Example:

Code:

The form-control-feedback class was also necessary with the glyphicon icon to set icon in the box of the input form.

Example:

Code:

Types of Bootstrap Forms Validation

There are 3 types of bootstrap form as mentioned below:

1. has-success

This class used to get the message of success. With this validation class, users need also “glyphicon glyphicon-ok” icon to show the icon of success. If the user enters the input in the form correctly then this validation worked.

The has-success class comes up with a parent class. To get the success message to use this validation used. The below example gives the horizontal form format. Output comes with the message in the green color.

Syntax:

Example:

Code:

Output:

Bootstrap Forms Validation Output 1

2. has-warning

This class used for warning messages of form input. With this validation class, users need also a “glyphicon glyphicon- warning-sign” icon to show the icon of warning. If we enter the wrong input in the form, we have one more chance to enter input that time warning validation worked.

Warning validation class placed in parent class with a has-feedback class. If the user gets the warning of some kind of mistake then this class worked. The outcome comes with the message in yellow color.

Syntax:

Example:

Code:

Output:

Bootstrap Forms Validation Output 2

3. has-error

This class used for error message of form input. With this validation class, users need also “glyphicon glyphicon-remove” icon to show the icon of error. If we enter the wrong input in the form, this validation worked.

Error validation class placed in parent class with a has-feedback class. If the user gets the error message of mistake then this class worked.

Syntax:

Example:

Code:

Output:

Bootstrap Forms Validation Output 3

Explanation:

  •  All form is a horizontal layout. The label has 2 columns and input has 10 columns. Validation class set with has-feedback into parent div. To see the icon user used glyphicon icons with form-control-feedback in the <span>
  • Users work on the password. either password is correct then success validation bootstrap error label or password is wrong then error validation work. If the password has some mistake and we can able to recorrect then warning validation work.

Examples bootstrap error label Bootstrap Forms Validation

Below are the different examples of bootstrap forms validation:

Example #1

The following example is Validation with the horizontal form. Glyphicon sign is work on the inner input box in the form. Label and input in one horizontal socket error 11004 no delphi but all form-group class is vertically placed.

Code:

Output:

Output 4

Example #2

The following example is Validation with the vertical form. In the vertical form, all labels and inputs are vertical situated. Glyphicon can be situated in the line of the label at the end of the input box.

There is no class in the form. It is rarely used in form validation in bootstrap.

Code:

Output:

Output 5

Example #3

The following example is Validation with the inline form. The inline form has all labels and input in one line including all form groups. This is a complicated but validation icon placed in the input box of the form.

If users need only small form and login form then with validations then the inline form can apply.

Code:

Output:

Output 6

Above all example has all validation type with all layout and how it works. As per user requirement and easiness choose the format of form validation and layout.

Conclusion

Mostly form validation occurs on the server-side to control data of form in a database. For those purposes, we get many complicated coding and using the validation method using JavaScript language. Bootstrap did all things in one form page avoiding complications and lengthy coding and control the form data effortlessly.

Recommended Articles

This is a guide to Bootstrap Form Validation. Here we discuss the basic concept, 3 types of bootstrap forms validation along with the appropriate examples. You may also look at the following articles to learn more –

  1. What is Bootstrap?
  2. Bootstrap Commands
  3. Bootstrap Form Layout
  4. Bootstrap Collapse

Bootstrap 5 Form Validation

❮ PreviousNext ❯


Form Validation

You can use different validation classes to provide valuable feedback to users. Add either or to the element, delphi thread creation error on whether you want to provide validation feedback before or after submitting the form. The input fields will have a green (valid) or red (invalid) border to indicate what's missing in the form. You can also add a or message to tell the user explicitly what's missing, or needs to be done before submitting the form.

Example

In this example, we use to indicate what's missing before submitting the form:

<form action="/action_page.php" class="was-validated">
  <div class="mb-3 mt-3">
    <label for="uname" class="form-label">Username:</label>
    <input type="text" class="form-control" id="uname" placeholder="Enter username" name="uname" required>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Please fill out this field.</div>
  </div>
  <div class="mb-3">
    <label for="pwd" class="form-label">Password:</label>
    <input type="password" class="form-control" id="pwd" placeholder="Enter password" name="pswd" required>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Please fill out this field.</div>
  </div>
  <div class="form-check mb-3">
    <input class="form-check-input" type="checkbox" id="myCheck" name="remember" required>
    <label class="form-check-label" for="myCheck">I agree on blabla.</label>
    <div class="valid-feedback">Valid.</div>
    <div class="invalid-feedback">Check this checkbox to continue.</div>
  </div>
  <button type="submit" class="btn btn-primary">Submit</button>
</form>

Try it Yourself »

❮ PreviousNext ❯


Validation

import Button from'react-bootstrap/Button';

import Col from'react-bootstrap/Col';

import Form from'react-bootstrap/Form';

import InputGroup from'react-bootstrap/InputGroup';

import Row from'react-bootstrap/Row';

const{ Formik }= formik;

const schema = yup.object().shape({

firstName: yup.string().required(),

lastName: yup.string().required(),

username: yup.string().required(),

city: yup.string().required(),

state: yup.string().required(),

zip: yup.string().required(),

terms: yup.bool().required().oneOf([true],'Terms must be accepted'),

});

functionFormExample(){

return(

<Formik

validationSchema={schema}

onSubmit={console.log}

initialValues={{

firstName:'Mark',

lastName:'Otto',

socket 10049 error username:'',

city:'',

state:'',

zip:'',

terms:false,

}}

>

{({

handleSubmit,

handleChange,

handleBlur,

values,

touched,

isValid,

errors,

})=>(

<FormnoValidateonSubmit={handleSubmit}>

<RowclassName="mb-3">

<Form.Groupas={Col}md="4"controlId="validationFormik01">

<Form.Label>First name</Form.Label>

<Form.Control

type="text"

name="firstName"

value={values.firstName}

onChange={handleChange}

isValid={touched.firstName &&!errors.firstName}

/>

<Form.Control.Feedback>Looks good!</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="4"controlId="validationFormik02">

<Form.Label>Last name</Form.Label>

<Form.Control

type="text"

name="lastName"

value={values.lastName}

onChange={handleChange}

isValid={touched.lastName &&!errors.lastName}

/>

<Form.Control.Feedback>Looks good!</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="4"controlId="validationFormikUsername">

<Form.Label>Username</Form.Label>

<InputGrouphasValidation>

<InputGroup.Textid="inputGroupPrepend">@</InputGroup.Text>

<Form.Control

type="text"

placeholder="Username"

aria-describedby="inputGroupPrepend"

name="username"

value={values.username}

onChange={handleChange}

isInvalid={!!errors.username}

/>

<Form.Control.Feedbacktype="invalid">

{errors.username}

</Form.Control.Feedback>

</InputGroup>

</Form.Group>

</Row>

<RowclassName="mb-3">

<Form.Groupas={Col}md="6"controlId="validationFormik03">

<Form.Label>City</Form.Label>

<Form.Control

type="text"

placeholder="City"

name="city"

value={values.city}

onChange={handleChange}

isInvalid={!!errors.city}

/>

<Form.Control.Feedbacktype="invalid">

{errors.city}

</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="3"controlId="validationFormik04">

<Form.Label>State</Form.Label>

<Form.Control

type="text"

placeholder="State"

name="state"

value={values.state}

onChange={handleChange}

isInvalid={!!errors.state}

/>

<Form.Control.Feedbacktype="invalid">

{errors.state}

</Form.Control.Feedback>

</Form.Group>

<Form.Groupas={Col}md="3"controlId="validationFormik05">

<Form.Label>Zip</Form.Label>

<Form.Control

type="text"

placeholder="Zip"

name="zip"

value={values.zip}

onChange={handleChange}

isInvalid={!!errors.zip}

/>

<Form.Control.Feedbacktype="invalid">

{errors.zip}

</Form.Control.Feedback>

</Form.Group>

</Row>

<Form.GroupclassName="mb-3">

<Form.Check

required

name="terms"

label="Agree to terms and conditions"

onChange={handleChange}

isInvalid={!!errors.terms}

feedback={errors.terms}

feedbackType="invalid"

id="validationFormik0"

/>

</Form.Group>

<Buttontype="submit">Submit form</Button>

</

React Bootstrap Form Validation

Bootstrap vs React Bootstrap

First, bootstrap error label, let’s quickly discuss the difference between Bootstrap and React Bootstrap. Bootstrap is one of the oldest and most-used CSS libraries for Javascript. It was launched by Twitter in 2009 and gets downloaded close to 2.5 million times every week.

Bootstrap was never intended to be used with React—React hadn’t even been created when Bootstrap launched. While it’s a powerful JavaScript library, Bootstrap doesn’t play well with React. The problem is that under the hood, bootstrap error label, Bootstrap relies heavily on JQuery to manipulate the DOM, while React uses a virtual DOM to make changes. Any changes that bootstrap error label applied to the DOM with Bootstrap via JQuery do not get picked up by React.

React Bootstrap eliminates the reliance on JQuery and packages all of Bootstrap’s native components into pure React components. These components, along with Bootstrap's existing CSS styling and templates, can be imported as React components into a React project. 

Getting Started

To get started with form validation, we’ll spin up a React app using Create React App and install both Bootstrap and React Bootstrap into the project.

Once the dependencies are installed, start up the app

and head to http://localhost:3000 to check that the app is running.

Great! We’re ready to start coding. Open up the bootstrap error label in your favorite editor (VS Code is a good choice) and bootstrap error label the Bootstrap stylesheet. This will allow us to bootstrap error label Bootstrap classes on bootstrap error label components and elements. You can also remove the boilerplate code from App.js. 

Once our email form validation component is complete, we’ll import it into this file and render bootstrap error label between the divs.

Building the Form Component

Create a new file called EmailForm.js next to App.js inside src. This is the file where we’ll write all our form validation logic and render the email form component. 

Inside the file, import the Form component and the Button component. Create a top-level React component called EmailForm and render the Form component inside.

Let’s break this down.

The Form component wraps the whole form and allows us to access its children through dot notation. The Form Group wraps bootstrap error label parts of the form. In this case, we only have one part: the email input. The Form Label allows us to give a label to the form.

The main piece of logic here is the Form Control. By telling this component that we are expecting a type of “email” we have already told React Bootstrap enough to provide us with some basic form validation, bootstrap error label. We’ll see how this validation works in a moment.

Because we’ve included the Button component inside the Form and given it a type of “submit,” React Bootstrap knows that this button needs to do form validation and form submission of the associated form when clicked.

As you can see, we’ve used some Bootstrap classes (d-flex flex-column align-items-center) on our outermost div to apply some basic styling. This styling comes from the stylesheet we imported in App.js.

Rendering the Form Component

Import your EmailForm component into App.js and render it between the divs

and head back to http://localhost:3000 to check out our newly rendered form

At this point, we'll get some basic email validation right out of the box. Try inputting an invalid email address into bootstrap error label input and hitting the “Submit Form” button.

React Bootstrap detected that the email address is missing an expected character, and rendered an error message.

Validating With AbstractAPI

That level of validation is great, but what if we want something a little more robust? A third-party validation API like AbstractAPI’s Free Email Validation API can tell us not only if an email is valid, but also give us some more useful information, like whether the address is currently deliverable and if the SMTP 3265 error visual basic valid, and a quality score for the email.

This tells us not only that the user’s input string contained all the expected characters for a properly formatted email, bootstrap error label, but also whether or not the email actually exists.

Let’s add a validation step to check the email input against AbstractAPI before we submit bootstrap error label Started With the API

First, let’s get set up with an API key. You’ll need an API key to use any of AbstractAPI's endpoints. Each API requires a unique key, so even if you’ve used an AbstractAPI API before, you’ll need a new key for this one.

Navigate to the Email API homepage and click “Get Started.”

If you’ve never used Abstract before, you’ll be asked to create an account using your email and password. Don’t worry—you won’t be charged bootstrap error label anything, bootstrap error label. All of AbstractAPI’s endpoints are free to use for development.

Once you’ve created an account and logged in, you’ll land on the API homepage where you’ll see your API key, plus links to documentation, a sandbox for making test requests, and support information. 

Copy your API key. We’re going to use it in the next step.

Adding Custom Form Logic

Right now, Bootstrap is handling all of the form logic for us, bootstrap error label. In order to validate our email using AbstractAPI, we need to store the email somewhere in the state, bootstrap error label. We also need to add an onChange handler to update the state when a user inputs their email, and an onSubmit handler to perform the additional validation when the user clicks “Submit Form.”

Inside EmailForm.js, create a function called sendValidationRequest. This will handle taking the email our user has input.

In real life, the handleSubmitEmail handler would send the email to our backend. For the purposes of this tutorial, we’ll just log the email to the console.

Next, we need to add the validation step into our handleSubmitEmail function.

Sending the Validation Request

In order to validate the email with AbstractAPI, we first need to send the email to the API, bootstrap error label. To do that, we’ll need an HTTP client. React comes with the fetch client built-in, and it’s available as a global bootstrap error label. The NPM packageaxiosis another easy-to-use alternative. For now, we’ll use fetch.

Next, create the URL where fetch will send the request. Per the AbstractAPI docs, bootstrap error label, the URL needs to include our API key and the email we want to validate.

Right now, we’re not including the email because we don’t know what it is yet. The email will be appended to the Bootstrap error label after the user inputs it, and before we send the request.

Create a function called sendEmailValidationRequest. This is where we’ll pull our email out of state and send it to the API for validation. 

The validationResponse will contain the JSON object that the AbstractAPI endpoint sends back.  Note that we’ve used await twice to access the JSON object inside the response: once to await the response from the network, bootstrap error label, and again to parse the response into Bootstrap error label JSON object will contain information about whether our email is valid, along with the other information. It should look something like this:

Let’s add the sendValidationRequest function as the first step in our handleSubmit function.

Next, we need to examine the API’s response and use it to determine whether we should submit the email or not.

Using the API Response in Form Validation

The most important part of the API JSON response is the is_valid_format object, which contains a boolean value field. This field will tell us whether or not the email is properly formatted. We only want to submit the email if this field is “true.”

Let’s return the value of this field from our sendValidationRequest function, and add some conditional logic to check the value of it inside handleSubmitEmail.

Great! We’ve successfully validated an email and used its validity to determine whether or not to send it to our database.

Next, we need to let the user know whether or not their email was valid. We can use React Bootstrap’s Form Control Feedback component to do this.

Rendering an Error Message

If the email is invalid, we need to let the user know. We’ll add a Feedback component with an error message in it if the is_valid_format.value response from the API comes back “false.”

First, we need to create a value in the state to hold our error message.

As you can see, we’re initializing the errors value to be an object instead of a string. Why? We might want to render multiple errors. We’ll talk more about this in a moment.

Next, render the Form Control Feedback component below the FormControl component.

This component will display feedback to the user only if the errors object has an email field bootstrap error label is not “null.” It will also render whatever string is present in the errors.email field. 

To hook it up to our email Form Control component, we need to utilize the isInvalid field on the Form Control.

Let’s add the logic to render the error message.

Here, if the response from the API indicates that the email was invalid, we add an email field to the errors object, and populate it with the error message we want to show our user. If the response was valid, bootstrap error label, we clear any email error that might have previously been shown bootstrap error label submit the email.

Head back to http://localhost:3000 and try to submit an invalid email.

Note: AbsctractAPI does some clever stuff with bootstrap error label. If the hawke chairgun pro run time error 13 inputs an email like “[email protected]” for example, Abstract will autocorrect the email to “[email protected]” and return that the email was valid. 

Putting it All Together

Here’s what our EmailForm.js file should look like when all is said and done:

That’s all it takes to get a basic email validation form up and running with AbstractAPI.

Conclusion

There are still many things that can be improved upon here. 

For starters, we’re not handling errors that might arise from network failures (404, 500, etc.) or other issues that might come up when trying to send a request to the API endpoint.

Next, we could add a loading spinner when the user hits “Submit Form” and disable the “Submit Form” button to indicate to the user that something is happening, and prevent the user from clicking the button multiple times.

Finally, bootstrap error label could hook up the form validation function to be called in the onBlur handler so that the email gets validated before the user hits submit. We could also put it in the onChange handler if we wanted to validate at every keystroke (this would also require us to debounce the request.)

But for now, we’ve made a pretty good start on form validation for email!

FAQs

What is React Bootstrap?

React Bootstrap is a component library that bundles the styling and reusable components of Bootstrap into pure React components. It allows Bootstrap to seamlessly integrate with React’s virtual DOM, rather than relying on JQuery to make DOM updates.

What is the difference between Bootstrap and React Bootstrap?

Bootstrap is a JavaScript framework, released by Twitter in 2011. It is one of the most popular libraries for Javascript, with over 2.5 million downloads every week. Bootstrap is first and foremost a CSS framework that allows you to apply pre-defined classes to DOM elements and then organizes and styles those elements for you. It also exports some pre-made components that can be used inside your web app.

React Bootstrap error label takes Bootstrap’s pre-defined styles and bundles them into reusable React components. You can import these components into your app. Vanilla Bootstrap does not play well with React because of the use of JQuery, which manipulates the DOM, bootstrap error label. React relies on a shadow or virtual DOM to perform updates, so Bootstrap changes applied to the DOM are not picked up by React.

What is form validation?

Form validation is an important part of frontend web and mobile development. It is the process of ensuring that the input users have given you is correct and well-formatted. An email validation form, for example, checks that the provided email contains all the expected characters (like ‘@’ and ‘.com’) and that it doesn’t contain any unexpected characters or malicious scripts.

Form validation not only prevents your users from inputting the wrong information, it protects them and your system from attacks from bad actors.

Bootstrap CSS Classes super frame errors upstream Styling Validation Messages

In the previous section, we applied AngularJS built-in CSS classes to a form. Here, we will apply bootstrap CSS classes for styling form field error, warning, or validity.

Bootstrap includes following CSS classes for the form validation.

Bootstrap CSS Class Description
has-error Set this CSS class when a form field becomes invalid based on applied validation attributes.
has-warning Set this CSS class to display warning for a form field.
has-success Set this CSS class when a form field becomes valid based on applied validation attributes.

The following is a student form with bootstrap validation classes.

In the above example, we have applied ng-class directive to each <div> element with CSS class name and an expression. If an expression evaluates to true then specified CSS class will be applied.

youtube video

Working Example Bootstrap 4 Alert Messages - Popup for Success and Error Messages

0 Comments

Leave a Comment