Joomla 3.x -> 4.x Migration Guide for Extensions

[gsexton]

Can someone point me to a migration guide for Joomla extensions from 3.x -> 4.x?

I'm getting this error:

Call to undefined method Joomla\CMS\Document\HtmlDocument::addStyleSheetVersion()

I've read this page:

https://docs.joomla.org/Potential_backw ... oomla_4/en

and I'm not seeing anything that looks related. Is there an upgrade or migration guide targeted for extension developers?

[toivo]

The function addStyleSheetVersion() is a Joomla 3 function that is part of the class Document, defined in the file libraries/src/Document/Document.php. That function does not exist in Joomla 4.

Which front end template is this website using? Are all the third party extensions compatible with Joomla 4?

Set 'Error Reporting' in the Global Configuration to 'Maximum' and turn on the Debug System option in the System tab and the error message and the PHP call stack will identify the script and the line number, where the error message comes from. Post the details here for advice.

[toivo]

Sorry, if you are about to convert an extension to Joomla 4, you probably know all about the above! The documentation block of the function addStyleSheetVersion() in Joomla 3.10.12 gives this advice, which is inaccurate, because the function was not just deprecated but actually removed in Joomla 4:

Code: Select all

	 * @deprecated 4.0  This method is deprecated, use addStyleSheet(url, options, attributes) instead.

The function addStyleSheet() is defined in libraries/src/Document/Document.php:

Code: Select all

    /**
     * Adds a linked stylesheet to the page
     *
     * @param   string  $url      URL to the linked style sheet
     * @param   array   $options  Array of options. Example: array('version' => 'auto', 'conditional' => 'lt IE 9', 'preload' => array('preload'))
     * @param   array   $attribs  Array of attributes. Example: array('id' => 'stylesheet', 'data-test' => 1)
     *
     * @return  Document instance of $this to allow chaining
     *
     * @since   1.7.0
     *
     * @deprecated  4.3 will be removed in 6.0
     *              Use WebAssetManager
     *              Example: $wa->registerAndUseStyle(...);
     */
    public function addStyleSheet($url, $options = [], $attribs = [])
    {

An example of the function call can be found in the function stylesheet() in libraries/src/HTML/HTMLHelper.php.

If you prefer the latest, non-deprecated method, use the WebAssetManager, mentioned in the documentation block above: J4.x: Web Assets - Methods to Work with Styles

[robbiej]

For components there's a step in the Joomla 3 MVC Tutorial at Upgrading to Joomla 4