Laravel's Form Model Binding is a feature implemented through the laravelcollective/html package that automatically fills model data into form fields. 1. You need to install the package and configure the service provider and facade first; 2. Use Form::model() to bind model instances in the Blade template; 3. The form field name must be consistent with the model attributes for automatic filling; 4. Pay attention to closing the form and using the HTTP method correctly; 5. Applicable to editing scenarios, and you can pass empty models when creating; 6. It is more concise than native HTML and reduces the risk of missing backfill logic, but it is not applicable in Livewire or Inertia.js.

Of course, Laravel's Form Model Binding is a very practical feature, especially when dealing with form editing scenarios, which can greatly simplify code and reduce duplicate logic. Next I will directly talk about the key points and usage methods.

What is Form Model Binding?

Form Model Binding is a feature provided by the laravelcollective/html extension package in Laravel. It allows you to bind a model instance in the form, so that the corresponding value will be automatically filled when rendering the form field.

For example, if you have a user editing page, you don’t need to manually set the value of the input box one by one, it will automatically match according to the model.

How to install and configure

If you are using the newer Laravel version (8), you need to install this package first:

 composer requires laravelcollective/html

Then add in the providers array of config/app.php :

 Collective\Html\HtmlServiceProvider::class,

And add two facades in aliases :

 'Form' => Collective\Html\FormFacade::class,
'Html' => Collective\Html\HtmlFacade::class,

After this step is completed, you can start using it.

How to use it in Blade templates

Suppose you are editing a user information page and the controller has passed in the $user instance.

You can write this way:

 {!! Form::model($user, ['route' => ['users.update', $user->id], 'method' => 'PUT']) !!}
    {{ Form::text('name') }}
    {{ Form::email('email') }}
    {{ Form::submit('Update') }}
{!! Form::close() !!}

The key here is Form::model() method, which binds the model. Each field after that will automatically fill the value as long as the name corresponds to the model attribute.

Frequently Asked Questions and Notes

• The field name must be consistent with the model attribute : otherwise it will not be automatically filled.
• Avoid field conflicts : An error may occur if the field name is duplicated with the key in the form request.
• Remember to close the model binding : use Form::close() or end the !!} tag.
• The POST/PUT/PATCH method should be used in conjunction with the routing method : for example, the update operation should be used method="PUT" and with Route::put() .

If you also want to use this syntax when creating new data, you can pass an empty model in:

 $user = new App\Models\User();
Form::model($user, ...)

What is the difference between it and ordinary forms?

Compared to writing HTML forms directly:

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

Using Form Model Binding is more concise and it is not easy to miss old() backfilling logic. Especially when there are many fields and data echoes after verification failure, the advantages are more obvious.

However, if you are using Laravel Livewire or Inertia.js, you may not need to use this package because they have their own form state management methods.

Basically, that's not complicated but it's easy to ignore details. For example, forgetting to bind the model or the field name doesn't match, will cause the data to not be displayed.

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