Output Buffering Directive for Laravel Blade Templates

readme.md

Output Buffering Directive for Laravel Blade Templates

This is a simple output buffering directive for Laravel's Blade templating engine. It can be used to buffer output (e.g. from other directives) into a variable.

The @buffer directive starts buffering output, the @endbuffer directive stops it. @endbuffer also takes a variable name as an optional parameter to store the buffered output in. If no variable name is provided, all buffered output will be discarded.

The concrete example that sparked the idea for this directive was to take a Blade template with SVG contents and use it as a Base64 encoded SVG favicon — like this:

@buffer
@include('icons.laravel', [ 'fill' => '#ff2d20' ])
@endbuffer('icon')
<link rel="icon" type="image/svg+xml" href="data:image/svg+xml;base64,{{ base64_encode($icon) }}" sizes="any">

buffer.php

<?php
// In your AppServiceProvider's boot() method, put this:

Blade::directive('buffer', function () {
    return '<?php ob_start(); ?>';
});

Blade::directive('endbuffer', function (string $name) {
    if ($name === '') {
        return '<?php ob_end_clean(); ?>';
    } else {
        $name = preg_replace('/^(["\'])(.+)\1$/', '$2', $name);

        if (!preg_match('/^[a-z][0-9a-z_]*$/i', $name)) {
            throw new UnexpectedValueException(sprintf(
                'Invalid variable name "%s" to hold buffered content',
                $name
            ));
        }

        return "<?php $$name = ob_get_contents(); ob_end_clean(); ?>";
    }
});