How to Set Variables in a Laravel Blade Template

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?

Solution 1:

LARAVEL 5.5 AND UP

Use the full form of the blade directive:

@php
$i = 1
@endphp

LARAVEL 5.2 - 5.4

You can use the inline tags:

@php ($i = 1)

Or you can use it in a block statement:

@php
$i = 1
@endphp

ADD A 'DEFINE' TAG

If you want to use custom tags and use a @define instead of @php, 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.

Solution 2:

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);
});

Solution 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.