Hi all,
We started to use the new widget libraries today, and encountered a
number of semantic issues, mainly related to difficulties to clearly map
names to concepts.
To use libraries, we currently have at hand:
- <fd:import> to make a library available for reuse in the current form
(or library) definition.
- <fd:expand> to import a widget defined in a library in the current
definition
- <fd:class> to define a group of widgets with no surrounding container
- <fd:new> to expand the contents of a <fd:class> in the current container
These names make it very difficult to understand what does what. I'd
like therefore to propose a renaming:
- rename <fd:class> to <fd:macro> (this is the wording used on the wiki
[1][2])
- rename <fd:new> to <fd:expand>: "expanding" is the word used
traditionally to denote insertion of the macro contents at the current
location.
- rename <fd:import> to <fd:load-library>, to clearly indicate that
widgets in the library are made available but not inserted right now, in
contrast with <jx:import> in JXTG that executes the imported template.
- rename <fd:expand> to <fd:insert> (or <fd:use>?)
For this last item, it has to be noted that it is equivalent to an
"untyped extension", i.e.
<fd:insert ref="lib:myfield"/>
is equivalent to
<fd:field extends="lib:myfield"/>
if of course "myfield" is a field.
Also, I think we should allow <fd:load-library> only as first-level
children of <fd:form> and <fd:library>, as it doesn't really make sense
to load a library anywhere in a definition, and it further clarifies
that libraries are not expanded a the place where they are loaded.
<fd:form>
<fd:load-library prefix="lib" src="lib.xml"/>
<fd:widgets>
....
</fd:widgets>
</fd:form>
We also encountered a problem with classes: if a library defines several
cross-referencing classes (i.e. class A has a <fd:new id="B"> and class
B has a <fd:new id="A">), then the second <fd:new> fails because it
searches in the current form whereas it should search in the originating
definition.
WDYT?
Sylvain
[1] http://wiki.apache.org/cocoon/CocoonFormsScratchpad
[2] http://wiki.apache.org/cocoon/WhiteBoardCocoonForms
--
Sylvain Wallez Anyware Technologies
http://people.apache.org/~sylvain http://www.anyware-tech.com
Apache Software Foundation Member Research & Technology Director
