46108 - add "never compute 'empty'" switch to XUL template builder

Status: RESOLVED FIXED

(Core :: XUL, defect, P3)

Description

[Chris Waterson]

We need to add a flag that tells the XUL template builder never to compute the 
"empty" attribute. This will avoid over-zealous forward crawling of RDF 
datasources, which is causing several bugs with menus and RDF datasources that 
rely on "GetTarget[s]()" to know when to go out and look for information (e.g., 
bookmarks, filesystem, search...)

Comment 1

[Chris Waterson]

This is the "rest" of the fix for 38233.

Comment 2

[Robert John Churchill]

It might be too late for this (unsure as to how many usages of "empty" there are 
in the tree; originally, this was purely for Mail/News, right?), but I'm 
wondering if the "default" should instead be to *never* compute empty, and 
instead have a flag to turn *on* "empty" computation.  Thoughts?

Comment 3

[David Hyatt]

I say we put this on the widget rather than on the template, i.e., just like the 
containment attribute.

e.g.,

<tree datasources="rdf:shadowland" builderflags="nevercheckempty,etc."
  ...

Comment 4

[David Hyatt]

I agree with Robert.  I think the default should be to never compute empty.  If 
putterman wants this feature, we can put it in mail/news and let them have this, 
but it doesn't seem like something you want by default.

Comment 5

[Chris Waterson]

cc'ing putterman. sound ok?

Comment 6

[scottputterman]

as I told hyatt, I don't really care as long as mailnews still works.  I'm 
assuming this comes into play for twisties(at least it does in mailnews). In 
that case I'm still not sure why it would be the common case to put twisties on 
empty containers.

Comment 7

[Chris Waterson]

Attachment: implement "flags='dont-test-empty'"

Comment 8

[David Hyatt]

Attachment: Patch for rdf/content/src to make menu-crawling non-aggressive.

Comment 9

[David Hyatt]

Attachment: Patch to layout/xul/base/src to make menu building from RDF non-aggressive

Comment 10

[Chris Waterson]

Beware there are some other diffs mixed up with the nsXULTemplateBuilder.cpp 
changes!

Also, for this:

RCS file: /cvsroot/mozilla/layout/xul/base/src/nsMenuFrame.cpp,v
retrieving revision 1.139
diff -u -r1.139 nsMenuFrame.cpp
--- nsMenuFrame.cpp     2000/07/07 22:24:01     1.139
+++ nsMenuFrame.cpp     2000/07/25 05:35:36
@@ -508,7 +508,6 @@
     viewManager->SetViewVisibility(view, nsViewVisibility_kHide);
     viewManager->ResizeView(view, 0, 0);
     // set here so hide chain can close the menu as well.
-    mMenuOpen = PR_FALSE;
   }
   

Did you want to remove the comment, as well?

Otherwise, looks good. r=waterson

Comment 11

[Chris Waterson]

hyatt checked in the fix for this