The Asset helper is used to map asset names to versioned assets.

This can be used to allow using a single, canonical name for an asset within your view scripts, while having that map to:

  • A versioned asset name, used to prevent browser caching.
  • A product of a build process (such as a CSS pre-processor, JS compiler, etc.)

Configuration and Basic Usage

Zend\View\Helper\Service\AssetFactory checks the application configuration, making it possible to set up the resource map through your module.config.php or application configuration. As an example:

'view_helper_config' => [
    'asset' => [
        'resource_map' => [
            'css/style.css' => 'css/style-3a97ff4ee3.css',
            'js/vendor.js' => 'js/vendor-a507086eba.js',

Within your view script, you would reference the asset name:

// Usable in any of your .phtml files:
echo $this->asset('css/style.css');

which then emits the following output:


The first argument of the asset helper is the regular asset name, which will be replaced by the associated value defined in the resource_map of the configuration.


When an asset key is specified but the resource_map is not provided or is not an array, the helper will raise a Zend\View\Exception\RuntimeException.

When you call the asset helper with a parameter not defined in your resource_map, the helper will raise a Zend\View\Exception\InvalidArgumentException.

Resource map in JSON file

A number of build tools, such as gulp-rev and grunt-rev, will create a JSON resource map file such as rev-manifest.json:

    "css/style.css": "css/style-3a97ff4ee3.css",
    "js/vendor.js": "js/vendor-a507086eba.js"

You can incorporate these into your configuration manually by fetching and decoding the contents:

'view_helper_config' => [
    'asset' => [
        'resource_map' => json_decode(file_get_contents('path/to/rev-manifest.json'), true),

If you have enabled configuration caching, these values will also be cached, meaning that the above operation will occur exactly once in your production configuration.

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