What is the usage of laravel form class

The usage of laravel form class is: 1. Form validation, which provides a simple and powerful way to verify form data. You can use the validate method to define validation rules and error messages; 2. Form refill, which provides Provides a convenient way to refill the value of the form field. You can use the old method to get the last submitted value; 3. File upload provides a convenient way to handle file upload. You can add a file upload field to the form. , and use the file method in the controller method to access the uploaded file, etc.

The operating environment of this article: Windows 10 system, Laravel9.x version, Dell G3 computer.

Laravel is a popular PHP framework that provides developers with a wealth of tools and features to simplify and speed up the development process. One of them is Laravel's form class, which provides developers with a convenient way to handle and validate form data. In this article, we will explore the usage of Laravel form classes.

The basic usage of Laravel form classes is very simple. First, you need to create a form in your view file. You can use Laravel's form helper functions to generate form elements. Here is a simple example:

<form method="POST" action="/submit">
    @csrf
    <input type="text" name="name">
    <button type="submit">Submit</button>
</form>

In this example, we use Laravel's @csrf directive to generate a CSRF token to protect the form from cross-site request forgery attacks. Then, we created a text input box and specified the field name using the name attribute. Finally, we create a submit button.

Next, we need to use the form class in the controller method that handles the form data. First, we need to import the form class:

use Illuminate\Http\Request;

Then, we can use the Request class in the controller method to access the form data. The following is a simple example:

public function submitForm(Request $request)
{
    $name = $request->input('name');
    // 处理表单数据
    return view('success');
}

In this example, we use the input method to get the value of the name field. You can also use the all method to get all form data. You can process form data in controller methods as needed, such as saving to a database or performing other operations.

In addition to basic usage, Laravel form classes also provide some other useful functions. The following are some commonly used functions:

1. Form validation: Laravel's form class provides a simple and powerful way to validate form data. You can use the validate method to define validation rules and error messages. Here is a simple example:

public function submitForm(Request $request)
{
    $validatedData = $request->validate([
        'name' => 'required|max:255',
    ]);
    // 处理表单数据
    return view('success');
}

In this example, we use the validate method to verify that the name field exists and is not empty, and that the length does not exceed 255 characters. If validation fails, Laravel automatically returns a redirect response containing an error message.

2. Form refill: Laravel's form class provides a convenient way to refill the form field values. You can use the old method to get the last submitted value. Here is a simple example:

<input type="text" name="name" value="{{ old(&#39;name&#39;) }}">

In this example, we use the old method to get the value of the name field submitted last time and fill it into the text input box.

3. File upload: Laravel's form class also provides a convenient way to handle file upload. You can add a file upload field to your form and use the file method in your controller method to access the uploaded file. Here is a simple example:

<form method="POST" action="/submit" enctype="multipart/form-data">
    @csrf
    <input type="file" name="photo">
    <button type="submit">Submit</button>
</form>

In this example, we set the form's enctype attribute to multipart/form-data to support file upload. We then created a file upload field and specified the field name using the name attribute. In the controller method, we can use the file method to access the uploaded file:

public function submitForm(Request $request)
{
    $file = $request->file('photo');
    // 处理文件上传
    return view('success');
}

These are just some common uses of Laravel form classes. Laravel also provides many other features, such as form redirection, form model binding, etc. You can refer to the Laravel documentation to learn more about the usage and functionality of the form class.

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