Moodle 4.2 developer update

This page highlights the important changes that are coming in Moodle 4.2 for developers.

External API

The external_api class, and all related classes have been moved from lib/externallib.php to namespaced classes within the core_external subsystem.

Delayed deprecation

The old class locations have been aliased for backwards compatibility and will emit a deprecation notice in a future release. Please remember to add require_once($CFG->dirroot . '/lib/externallib.php'); to your external service classes to make the aliases work.

If you are writing a Moodle plugin which has a single codebase shared with older versions of Moodle, you should continue to use the old API locations at this time.

The following parts of the external API have been moved to the core_external subsystem.

Renamed External API classes

Old class name	New class name
external_api	core_external\external_api
external_description	core_external\external_description
external_files	core_external\files
external_format_value	core_external\external_format_value
external_function_parameters	core_external\external_function_parameters
external_multiple_structure	core_external\external_multiple_structure
external_settings	core_external\external_settings
external_single_structure	core_external\external_single_structure
external_util	core_external\util
external_value	core_external\external_value
external_warnings	core_external\external_warnings
restricted_context_exception	core_external\restricted_context_exception

Renamed External API functions

Old function name	New function name
external_format_string()	core_external\util::format_string()
external_format_text()	core_external\util::format_text()
external_create_service_token()	core_external\util::generate_token()
external_generate_token()	core_external\util::generate_token()
external_generate_token_for_current_user()	core_external\util::generate_token_for_current_user()
external_log_token_request()	core_external\util::log_token_request()

Validation of $required parameter

The $required parameter in \core_external\external_description is now being validated. This is in order to prevent accidentally passing incorrect parameters to the external_description's and its subclasses' constructors.

An example of incorrect behaviour

'contentformat' => new external_format_value('content', 'Content format'),

In this example, the field description has been accidentally passed for the $required parameter in external_format_value's constructor. A debugging notice will be shown about the value Content format as an invalid value for the $required parameter.

An example of correct behaviour

'contentformat' => new external_format_value('content', VALUE_REQUIRED, 'Content format'),

The value for the $required parameter must either be set to either one of the VALUE_DEFAULT, VALUE_REQUIRED, or VALUE_OPTIONAL constants.

Quiz activity

At the moment, this is just a placeholder to say that there are significant changes in the Quiz activity (mod_quiz) in Moodle 4.2. A lot of the quiz code is being updated to modern Moodle coding standards while we add features in Epic MDL-74607. Therefore, if you have made customisations to the core quiz code, you will have work to do, and if you have made quiz sub-plugins (reports or access rules) you may have a small amount of work to do.

I will write a more coherent summary once the changes are complete, but mod/quiz/upgrade.txt lists all the changes so far.

Developer tip - handling changes to base class names, while supporting multiple Moodle versions

Thanks to Luca Bösch for working this out. If you want a single version of your plugin to support multiple version of Moodle without developer debug warnings, you can do it like this:

Work-around to support multiple base class names

// This work-around is required until Moodle 4.2 is the lowest version we support.
if (class_exists('quiz_default_report')) {
    class_alias('quiz_default_report', 'quiz_archive_parent_class_alias');
} else {
    class_alias('mod_quiz\local\reports\report_base', 'quiz_archive_parent_class_alias');
}

class quiz_archive_report extends quiz_archive_parent_class_alias {
    // Contents of your class unchanged.
}

Font Awesome 6

The Font Awesome third-party library has been upgraded from 4.7 to 6.3.0 in MDL-76989. The syntax has slightly changed. The free version included in Moodle only supports the solid and regular styles:

Version 4's syntax

<i class="fa fa-star"></i>
<i class="fa fa-star-o"></i>

Version 6's syntax

<i class="fa-regular fa-star"></i>
<i class="fa-solid fa-star"></i>

Font Awesome 6 is backwards compatible (because a shim has been included too), so the old syntax still works.

In the SCSS/CSS files some changes needs to be done to display the icons properly:

• The attribute content: $fa-var-xxx needs to be converted to content: fa-content($fa-var-xxx)
• The regular style is used by default. When the solid styled icon needs to be used, the following must be added: @extend .fa-solid. There are other ways to achieve the same. More information can be found in this page.
• @include fa-icons() is not required anymore (when it's used, the icons are not displayed properly).

More information about the changes between 4 and 6, including any icons which have been renamed, can be found in https://fontawesome.com/docs/web/setup/upgrade/upgrade-from-v4