install.rdf) to a JSON manifest (
manifest.json). Here is a basic example. This RDF manifest:
legacykey enables Thunderbird’s legacy support. Setting the
xulengages the new XUL overlay loader. The overlay loader is a Thunderbird component that takes XUL code as written in an overlay extension and applies it to the UI. In Thunderbird 60, this was a part of the core UI library, but it was removed. We have built a new overlay loader to replace as much of the removed code as possible.
optionskey to define the options page. The key
open_in_tabis optional and defaults to a value of
false. If your old RDF manifest included an
em:optionsTypeof 3, you can set
true, to have your options opened again in a new tab instead of a new window.
mailWindowOverlay.xul, that needs to be changed; in this example you most likely need to overlay
stylelines in your
chrome.manifestare now handled by the new overlay loader. You’ll see lines like this in the Error Console:
<script>tags added to an overlay file are now run after the application of the entire overlay, regardless of their position in the overlay. 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.