316
edits
Changes
Added note about when scripts are run be overlay loader
=== "Legacy" XUL extensions with overlays ===
"Legacy" XUL extensions with overlays are still "somewhat" supported in Thunderbird 63 and beyond. An inbuilt overlay loader will load XUL overlays for extensions but may cause graphical glitches or malfunctions. We're tracking this in {{bug|1476259}}.
Warning: Scripts in overlays are now run after all elements have been inserted into the document. This may cause unexpected behavior if your script previously ran before elements were inserted. For elements with event handlers these event handlers may run when the element is added, and they may fail if they rely on content being set up by a script which now runs after the creation of the element.
To use this overlay loader, XUL overlay legacy extensions must replace install.rdf file with a WebExtensions style manifest.json file, which includes the key "legacy" set to true. See Lightning as an example:<br />https://hg.mozilla.org/comm-central/rev/e81f4b59a00a7d3e18d50fd3851ecbd47762a186#l2.5 <small>(Note: In this changeset the @variables@ are build variables, add-ons need to use fixed strings)</small>.<br />
