What Is The Use Of Validation In Laravel With Example

Posted By Bajarangi soft , Posted On 17-09-2020

Laravel provides several different approaches to validate your application's incoming data. By default, Laravel's base controller class uses a ValidatesRequests trait which provides a cLaravel provides several different approaches to validate your application's incoming data. By default, Laravel's base controller class uses a ValidatesRequests trait which provides a convenient method to validate incoming HTTP requests with a variety of powerful validation rules.onvenient method to validate incoming HTTP requests with a variety of powerful validation rules.

What Is The Use Of Validation In Laravel With Example

Laravel's powerful validation features, let's look at a complete example of validating a form and displaying the error messages back to the user.

Defining The Routes

1.First, let's assume we have the following routes defined in our routes/web.php file:

Route::get('post/create', 'PostController@create');

Route::post('post', 'PostController@store');

The GET route will display a form for the user to create a new blog post, while the POST route will store the new blog post in the database.

2.Create PostController.php using below command

php artisan make:controller PostController

Creating The Controller

3.Open app\Http\PostController.php and Implement code as below

<?php

namespace App\Http\Controllers;


use Illuminate\Http\Request;

class PostController extends Controller
{

    public function Create(){

        return view('form');
    }
    
}

4.Now Create form.blade.php files in resource\views folder and implement code in it as below

<!DOCTYPE html>
<html>
<head>
    <title>Validation In Laravel</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
</head>
<body>
<div class="container">
    <div class="text-center">
        <h1>Validation In Laravel</h1>
    </div>
    <h2></h2>
    <div class="form-group col-sm-2"></div>
    <div class="form-group col-sm-8">
        <div class="well">
            <form method="post" action="{{url('formstore')}}">
                @csrf
                <div class="form-group col-sm-12">
                    <label>Title</label>
                    <input  class="form-control" type="text" name="title" value="">
                </div>
                <div class="form-group col-sm-12">
                    <label>Body</label>
                    <textarea  class="form-control" type="textarea" name="body" ></textarea>
                </div>
                <div class="form-group text-center">
                    <input  class="btn btn-primary" type="submit" >
                </div>
            </form>
            <div class="form-group col-sm-2"></div>
        </div>
    </div>
    <br>
</div>
</body>
</html>

Writing The Validation Logic

Now we are ready to fill in our store method with the logic to validate the new blog post. To do this, we will use the validate method provided by the Illuminate\Http\Request object. If the validation rules pass, your code will keep executing normally; however, if validation fails, an exception will be thrown and the proper error response will automatically be sent back to the user. In the case of a traditional HTTP request, a redirect response will be generated, while a JSON response will be sent for AJAX requests.

To get a better understanding of the validate method, let's jump back into the store method:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class PostController extends Controller
{
    public function Create(){

        return view('form');
    }
    public function store(Request $request){

        $validatedData = $request->validate([
            'title' => 'required|unique:posts|max:255',
            'body' => 'required',
        ]);
    }
}

As you can see, we pass the desired validation rules into the validate method. Again, if the validation fails, the proper response will automatically be generated. If the validation passes, our controller will continue executing normally.

Alternatively, validation rules may be specified as arrays of rules instead of a single | delimited string:

$validatedData = $request->validate([
'title' => ['required', 'unique:posts', 'max:255'],
'body' => ['required'],
]);

You may use the validateWithBag method to validate a request and store any error messages within a named error bag:

$validatedData = $request->validateWithBag('post', [
'title' => ['required', 'unique:posts', 'max:255'],
'body' => ['required'],
]);

Stopping On First Validation Failure

Sometimes you may wish to stop running validation rules on an attribute after the first validation failure. To do so, assign the bail rule to the attribute:

$request->validate([
'title' => 'bail|required|unique:posts|max:255',
'body' => 'required',
]);

In this example, if the unique rule on the title attribute fails, the max rule will not be checked. Rules will be validated in the order they are assigned.

A Note On Nested Attributes

If your HTTP request contains "nested" parameters, you may specify them in your validation rules using "dot" syntax:

$request->validate([
    'title' => 'required|unique:posts|max:255',
    'author.name' => 'required',
    'author.description' => 'required',
]);

Displaying The Validation Errors

So, what if the incoming request parameters do not pass the given validation rules? As mentioned previously, Laravel will automatically redirect the user back to their previous location. In addition, all of the validation errors will automatically be flashed to the session.

Again, notice that we did not have to explicitly bind the error messages to the view in our GET route. This is because Laravel will check for errors in the session data, and automatically bind them to the view if they are available. The $errors variable will be an instance of Illuminate\Support\MessageBag. For more information on working with this object, check out its documentation.

So, in our example, the user will be redirected to our controller's create method when validation fails, allowing us to display the error messages in the view:

<!-- /resources/views/post/create.blade.php -->

<h1>Create Post</h1>

@if ($errors->any())
    <div class="alert alert-danger">
        <ul>
            @foreach ($errors->all() as $error)
                <li>{{ $error }}</li>
            @endforeach
        </ul>
    </div>
@endif

<!-- Create Post Form -->

The @error Directive

You may also use the @error Blade directive to quickly check if validation error messages exist for a given attribute. Within an @error directive, you may echo the $message variable to display the error message:

<!-- /resources/views/post/create.blade.php -->

<label for="title">Post Title</label>

<input id="title" type="text" class="@error('title') is-invalid @enderror">

@error('title')
    <div class="alert alert-danger">{{ $message }}</div>
@enderror

A Note On Optional Fields

By default, Laravel includes the TrimStrings and ConvertEmptyStringsToNull middleware in your application's global middleware stack. These middleware are listed in the stack by the App\Http\Kernel class. Because of this, you will often need to mark your "optional" request fields as nullable if you do not want the validator to consider null values as invalid. For example:

$request->validate([
    'title' => 'required|unique:posts|max:255',
    'body' => 'required',
    'publish_at' => 'nullable|date',
]);

In this example, we are specifying that the publish_at field may be either null or a valid date representation. If the nullable modifier is not added to the rule definition, the validator would consider null an invalid date.

AJAX Requests & Validation

In this example, we used a traditional form to send data to the application. However, many applications use AJAX requests. When using the validate method during an AJAX request, Laravel will not generate a redirect response. Instead, Laravel generates a JSON response containing all of the validation errors. This JSON response will be sent with a 422 HTTP status code.

Complete code to validation

web.php

Route::get('post/create', 'PostController@create');

Route::post('post', 'PostController@store');

PostController.php

<?php

namespace App\Http\Controllers;


use Illuminate\Http\Request;

class PostController extends Controller
{

    public function Create(){

        return view('create');
    }
    public function store(Request $request){

        $validatedData = $request->validate([
            'title' => 'required|unique:posts|max:255',
            'body' => 'required',
        ]);
    }
}

Create.blade.php file

<!DOCTYPE html>
<html>
<head>
    <title>Validation In Laravel</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
</head>
<body>
<div class="container">
    <div class="text-center">
        <h1>Validation In Laravel</h1>
    </div>
    @if ($errors->any())
        <div class="alert alert-danger">
            <ul>
                @foreach ($errors->all() as $error)
                    <li>{{ $error }}</li>
                @endforeach
            </ul>
        </div>
    @endif
    <div class="form-group col-sm-2">

    </div>
    <div class="form-group col-sm-8">
        <div class="well">
            <form method="post" action="{{url('post')}}">
                @csrf
                <div class="form-group col-sm-12">
                    <label for="title">Post Title</label>

                    <input id="title" type="text" class="form-control @error('title') is-invalid @enderror">

                    @error('title')
                    <div class="alert alert-danger">{{ $message }}</div>
                    @enderror
                </div>
                <div class="form-group col-sm-12">
                    <label>Body</label>
                    <textarea  class="form-control @error('body') is-invalid @enderror" type="textarea" name="body" ></textarea>
                    @error('body')
                    <div class="alert alert-danger">{{ $message }}</div>
                    @enderror
                </div>
                <div class="form-group text-center">
                    <input  class="btn btn-primary" type="submit" >
                </div>
            </form>
            <div class="form-group col-sm-2"></div>
        </div>
    </div>
    <br>
</div>
</body>
</html>

Related Post

What Is The Use Of Validation In Laravel With Example
What Is Form Request Validation In Laravel With Example
How To Create Manual Form Validation In Laravel Framework
How To Create Validation Error Messages In Laravel
List The Available Validation Rules In Laravel With Example
List The Conditional Validation Rules In Laravel Framework
How To Do Validation Arrays In Laravel With Example
How To Do Custom Validation Rules In Laravel With Example
How To Do Form Validation Using HTML And JavaScript
How To Create Validation API With JavaScript With Example
How To Add From Validation Using Flutter Android App
How To Create Form Validation Wizard Using Html And CSS
Laravel Validation Rules