Code completion missing function description?

This is because OpenFL added externs for all of the Flash files, and HaxeDevelop prefers to import the externs because flash.display.* comes alphabetically before openfl.display.*.

As you can see, these externs don’t come with documentation, which is why HaxeDevelop doesn’t display any. It still compiles because there’s a typedef at the bottom, but HaxeDevelop isn’t smart enough to follow that typedef.

If you change import flash.display.BitmapData to import openfl.display.BitmapData, the documentation will come back. But it’s really inconvenient to do that every time.

Supposedly, you can hide folders to make HaxeDevelop ignore them, but this simply doesn’t work.

You could exclude the entire extern folder from code completion, but there’s one serious problem with that.

Problem is, the folder also contains the documentation. You want to exclude extern/flash while keeping extern/openfl.

Here is one way to do that: create an extern-flash folder alongside extern, and move extern/flash into there. Then add this tag to project.xml:

<source path="extern-flash" if="flash" unless="display" />

By the way, OpenFL may have fixed this since version 3.6.1. If you’re able/willing to update to OpenFL 4.1.0, that could be the simplest solution.