John Davidson

Message:

I used Blade::extend() to create a more complex directive than it is possible with Blade::directive(). After trying different approaches for hours, this is what I ended up with—and it works. Except for one thing, I'm still not entirely fine with:

When I pass $matches['callback'] (which contains ordinary blade syntax) to the output, Blade converts a string like this:

<a href="{{ route('user', [ 'user' => $user ]) }}">{{ $user->username }}</a>

to

<a href="<?php echo e(route('community.users.user', [ 'user' => $author->id ])); ?>"><?php echo e($author->username); ?></a>

This is done, because internally, Blade seems to use Blade::compileString(). That might be fine in some cases, but as you can probably see, it breaks the layout, because the whole <a /> tag has to be echo'd and the inner stuff has to be concatenated like this to return valid HTML:

'<a href="'. route('community.users.user', [ 'user' => $author->id ]) .'">'. $author->username .'</a>'

As you can see, I have a workaround, to manually replace {{ and }} so that string concatenation is happening, but I wonder if there's a way, to do that properly.

AppServiceProvider.php:

Blade::extend(function($expression) {

    $pattern = '/\@mapJoin\((?<collection>.*?), \'(?<variable>.*?)\', (?<delimiter>.*?)\)(?<callback>.*?)\@endMapJoin/ms';

    return preg_replace_callback($pattern, function($matches) {

        // @todo dynamic compiling

        $callback = preg_replace('/\{\{(.*?)\}\}/', "'.$1.'", trim($matches["callback"]));

        return '<?php echo '.$matches['collection'].'->map(function($'.$matches['variable'].') {

            return \''.$callback.'\';

        })->join('.$matches["delimiter"].'); ?>'; //Blade::compileString()

    }, $expression);

});

---

I wanted to have something in my blade syntax which allows me to do the following:

@mapJoin($story->authors, 'author', ',')

    <!-- normal markup and blade stuff -->

@endMapJoin

for example:

@mapJoin($story->authors, 'author', ',')

    <a href="{{ route('community.users.user', [ 'user' => $author->id ]) }}">{{ $author->username }}</a>

@endMapJoin

to turn it into:

$collection->map(function($variable) {

    return echo $callback;

})->join($delimiter);

which would result in:

<a href="community/users/user/1">User 1</a>, <a href="community/users/user/2">User 2</a>, <a href="community/users/user/1">User 2</a>

Blade::directive() sadly only replaces the @something itself, not the content between, and it does not have a concept of start and end tag. I tried to address that with my solution using Blade::extend(). Even more general, it would be something like this:

use Illuminate\Support\Facades\Blade;

use Illuminate\View\Compilers\BladeCompiler as CompilersBladeCompiler;

use Illuminate\Support\Str;



class BladeCompiler extends CompilersBladeCompiler

{

    public static function compileDirective(string $name, array $parameters, callable $callback)

    {

        $paramString = '';

        if (count($parameters)) {

            $paramString = '\(';

            foreach($parameters as $parameter) {

                $paramString .= '(?<'.$parameter.'>.*?)';

            }

            $paramString .= '\)';

        }

        return Blade::extend(function($expression) use($name, $paramString, $callback) {

            $pattern = '/\@'.$name.$paramString.'(?<content>.*?)\@end'.Str::studly($name).'/ms';

            return preg_replace_callback($pattern, $callback, $expression);

        });

    }

}

---

My Answer:
This is a complex issue and it seems like you have put a lot of effort into finding a solution. One possible approach to handle this issue could be to create a custom Blade directive that processes the content between the start and end tags in a way that suits your needs.

Here is an example of how you could create a custom Blade directive to achieve the desired output:

php
BladeCompiler::compileDirective('mapJoin', ['collection', 'variable', 'delimiter'], function($matches) {
$callback = preg_replace('/\{\{(.*?)\}\}/', '.$1.', trim($matches['content']));
return 'map(function($'.$matches['variable'].') {
return '.$callback.';
})->join('.$matches['delimiter'].'); ?>';
});


With this custom directive, you can use the following syntax in your Blade templates:

blade
@mapJoin($story->authors, 'author', ',')
{{ $author->username }}
@endMapJoin


This should output the desired result:

html
User 1, User 2, User 2


By creating a custom Blade directive, you have more control over how the content between the start and end tags is processed, allowing you to achieve the desired string concatenation output.