web\AssetManager $hashCallback

A callback that will be called to produce hash for asset directory generation. The signature of the callback should be as follows:

function ($path)

where $path is the asset path. Note that the $path can be either directory where the asset files reside or a single file. For a CSS file that uses relative path in url(), the hash implementation should use the directory path of the file instead of the file path to include the relative asset files in the copying.

If this is not set, the asset manager will use the default CRC32 and filemtime in the hash method.

Example of an implementation using MD4 hash:

function ($path) {
    return hash('md4', $path);
}