How to Set Variables in a Laravel Blade Template

问题

I\'m reading the Laravel Blade documentation and I can\'t figure out how to assign variables inside a template for use later. I can\'t do {{ $old_section = \"whatever\" }} because that will echo \"whatever\" and I don\'t want that.

I understand that I can do <?php $old_section = \"whatever\"; ?>, but that\'s not elegant.

Is there a better, elegant way to do that in a Blade template?

回答1:

It is discouraged to do in a view so there is no blade tag for it. If you do want to do this in your blade view, you can either just open a php tag as you wrote it or register a new blade tag. Just an example:

<?php
/**
 * <code>
 * {? $old_section = "whatever" ?}
 * </code>
 */
Blade::extend(function($value) {
    return preg_replace('/\{\?(.+)\?\}/', '<?php ${1} ?>', $value);
});

回答2:

LARAVEL 5.5 AND UP

The @php blade directive no longer accepts inline tags. Instead, use the full form of the directive:

@php
$i = 1
@endphp

LARAVEL 5.2 AND UP

You can just use:

@php ($i = 1)

Or you can use it in a block statement:

@php
$i = 1
@endphp

LARAVEL 5

Extend Blade like this:

/*
|--------------------------------------------------------------------------
| Extend blade so we can define a variable
| <code>
| @define $variable = "whatever"
| </code>
|--------------------------------------------------------------------------
*/

\Blade::extend(function($value) {
    return preg_replace('/\@define(.+)/', '<?php ${1}; ?>', $value);
});

Then do one of the following:

Quick solution: If you are lazy, just put the code in the boot() function of the AppServiceProvider.php.

Nicer solution: Create an own service provider. See https://stackoverflow.com/a/28641054/2169147 on how to extend blade in Laravel 5. It's a bit more work this way, but a good exercise on how to use Providers :)

LARAVEL 4

You can just put the above code on the bottom of app/start/global.php (or any other place if you feel that is better).

After the above changes, you can use:

@define $i = 1

to define a variable.

回答3:

In laravel-4, you can use the template comment syntax to define/set variables.

Comment syntax is {{-- anything here is comment --}} and it is rendered by blade engine as

<?php /* anything here is comment */ ?>

so with little trick we can use it to define variables, for example

{{-- */$i=0;/* --}}

will be rendered by bladeas <?php /* */$i=0;/* */ ?> which sets the variable for us. Without changing any line of code.

回答4:

There is a simple workaround that doesn't require you to change any code, and it works in Laravel 4 just as well.

You just use an assignment operator (=) in the expression passed to an @if statement, instead of (for instance) an operator such as ==.

@if ($variable = 'any data, be it string, variable or OOP') @endif

Then you can use it anywhere you can use any other variable

{{ $variable }}

The only downside is your assignment will look like a mistake to someone not aware that you're doing this as a workaround.

回答5:

Ya'll are making it too complicated.

Just use plain php

<?php $i = 1; ?>
{{$i}}

donesies.

(or https://github.com/alexdover/blade-set looks pretty straighforward too)

We're all kinda "hacking" the system by setting variables in views, so why make the "hack" more complicated then it needs to be?

Tested in Laravel 4.

Another benefit is that syntax highlighting works properly (I was using comment hack before and it was awful to read)

回答6:

You Can Set Variables In The Blade Templating Engine The Following Ways:

1. General PHP Block
Setting Variable: <?php $hello = "Hello World!"; ?>
Output: {{$hello}}

2. Blade PHP Block
Setting Variable: @php $hello = "Hello World!"; @endphp
Output: {{$hello}}

回答7:

Since Laravel 5.2.23, you have the @php Blade directive, which you can use inline or as block statement:

@php($old_section = "whatever")

@php
    $old_section = "whatever"
@endphp

回答8:

You can set a variable in the view file, but it will be printed just as you set it. Anyway, there is a workaround. You can set the variable inside an unused section. Example:

@section('someSection')
  {{ $yourVar = 'Your value' }}
@endsection

Then {{ $yourVar }} will print Your value anywhere you want it to, but you don't get the output when you save the variable.

EDIT: naming the section is required otherwise an exception will be thrown.

回答9:

In Laravel 4:

If you wanted the variable accessible in all your views, not just your template, View::share is a great method (more info on this blog).

Just add the following in app/controllers/BaseController.php

class BaseController extends Controller
{
  public function __construct()
  {                   
    // Share a var with all views
    View::share('myvar', 'some value');
  }
}

and now $myvar will be available to all your views -- including your template.

I used this to set environment specific asset URLs for my images.

回答10:

And suddenly nothing will appear. From my experience, if you have to do something like this prepare the html in a model's method or do some reorganizing of your code in to arrays or something.

There is never just 1 way.

{{ $x = 1 ? '' : '' }}

回答11:

I'm going to extend the answer given by @Pim.

Add this to the boot method of your AppServiceProvider

<?php
/*
|--------------------------------------------------------------------------
| Extend blade so we can define a variable
| <code>
| @set(name, value)
| </code>
|--------------------------------------------------------------------------
*/

Blade::directive('set', function($expression) {
    list($name, $val) = explode(',', $expression);
    return "<?php {$name} = {$val}; ?>";
});

This way you don't expose the ability to write any php expression.

You can use this directive like:

@set($var, 10)
@set($var2, 'some string')

回答12:

In Laravel 5.1, 5.2:

https://laravel.com/docs/5.2/views#sharing-data-with-all-views

You may need to share a piece of data with all views that are rendered by your application. You may do so using the view factory's share method. Typically, you should place calls to share within a service provider's boot method. You are free to add them to the AppServiceProvider or generate a separate service provider to house them.

Edit file: /app/Providers/AppServiceProvider.php

<?php

namespace App\Providers;

class AppServiceProvider extends ServiceProvider
{        
    public function boot()
    {
        view()->share('key', 'value');
    }

    public function register()
    {
        // ...
    }
}

回答13:

You may use the package I have published: https://github.com/sineld/bladeset

Then you easily set your variable:

@set('myVariable', $existing_variable)

// or

@set("myVariable", "Hello, World!")

回答14:

As for my elegant way is like the following

{{ ''; $old_section = "whatever"; }}

And just echo your $old_section variable.

{{ $old_section }}

回答15:

I don't think that you can - but then again, this kind of logic should probably be handled in your controller and passed into the view already set.

回答16:

If you have PHP 7.0:

The simple and most effective way is with assignment inside brackets.

The rule is simple: Do you use your variable more than once? Then declare it the first time it's used within brackets, keep calm and carry on.

@if(($users = User::all())->count())
  @foreach($users as $user)
    {{ $user->name }}
  @endforeach
@else
  There are no users.
@endif

And yes, I know about @forelse, this is just a demo.

Since your variables are now declared as and when they are used, there is no need for any blade workarounds.

回答17:

Assign variable to the blade template, Here are the solutions

We can use <?php ?> tag in blade page

<?php $var = 'test'; ?>
{{ $var }

We can use the blade comment with special syntax

{{--*/ $var = 'test' /*--}}
{{ $var }}

回答18:

Hacking comments is not a very readable way to do it. Also editors will color it as a comment and someone may miss it when looking through the code.

Try something like this:

{{ ''; $hello = 'world' }}

It will compile into:

<?php echo ''; $hello = 'world'; ?>

...and do the assignment and not echo anything.

回答19:

It's better to practice to define variable in Controller and then pass to view using compact() or ->with() method.

Otherwise #TLGreg gave best answer.

回答20:

There is a very good extention for Blade radic/blade-extensions. After you add it you can use @set(variable_name, variable_value)

@set(var, 33)
{{$var}}

回答21:

laravel 5 you can easily do this . see below

{{--*/ @$variable_name = 'value'  /*--}}

回答22:

I was looking for a way to assign a value to a key and use it many times in my view. For this case, you can use @section{"key", "value"} in the first place and then call @yield{"key"} to output the value in other places in your view or its child.

回答23:

In my opinion it would be better to keep the logic in the controller and pass it to the view to use. This can be done one of two ways using the 'View::make' method. I am currently using Laravel 3 but I am pretty sure that it is the same way in Laravel 4.

public function action_hello($userName)
{
    return View::make('hello')->with('name', $userName);
}

public function action_hello($first, $last)
{
    $data = array(
        'forename'  => $first,
        'surname' => $last
    );
    return View::make('hello', $data);
}

The 'with' method is chainable. You would then use the above like so:

<p>Hello {{$name}}</p>

More information here:

http://three.laravel.com/docs/views

http://codehappy.daylerees.com/using-controllers

回答24:

I had a similar question and found what I think to be the correct solution with View Composers

View Composers allow you to set variables every time a certain view is called, and they can be specific views, or entire view templates. Anyway, I know it's not a direct answer to the question (and 2 years too late) but it seems like a more graceful solution than setting variables within a view with blade.

View::composer(array('AdminViewPath', 'LoginView/subview'), function($view) {
    $view->with(array('bodyClass' => 'admin'));
});

回答25:

works in all versions of blade.

{{--*/  $optionsArray = ['A', 'B', 'C', 'D','E','F','G','H','J','K'] /*--}}

回答26:

You can extend blade by using the extend method as shown below..

Blade::extend(function($value) {
    return preg_replace('/\@var(.+)/', '<?php ${1}; ?>', $value);
});

after that initialize variables as follows.

@var $var = "var"

来源：https://stackoverflow.com/questions/13002626/how-to-set-variables-in-a-laravel-blade-template

标签

php

laravel

laravel-4

laravel-blade