h5p / h5p-wordpress-plugin

Adds support for H5P Content in WordPress.
https://wordpress.org/plugins/h5p/
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HFP-3065 Allow to delete library if circular dependency #125

Open otacke opened 3 years ago

otacke commented 3 years ago

A long time ago in a galaxy far far away, the H5PLibraryList class was created to allow H5P library management - including deletion of libraries. Libraries cannot be deleted, of course, if some content or library still depends on it.

Unfortunately, it is possible that a content library is used for the view and the editor alike, e.g. Course Presentation. H5P.CoursePresentation has an "editor" dependency to H5PEditor.CoursePresentation, and H5PEditor.CoursePresentation has a "preloaded" dependency to H5P.CoursePresentation. This direct circular dependency prevents both libraries from being deleted (without manually modifying the relevant entries in the h5p_libraries_libraries database table.

When merged in, this pull request will check for a direct circular dependency (no transitive circles of more than two libraries) when calling getLibraryUsage() and set a hasCircularEditorDepencendy flag in the return value if appropriate. That flag will be used to check whether a library can be deleted (if the respective editor library is the only library that requires the library at stake) or not.

In order to allow deletion using the GUI of the H5PLibraryList class, the pull request for the H5P core at https://github.com/h5p/h5p-php-library/pull/101 will have to me merged in as well.

This pull request could easily be ported to other integrations if it is accepted.