Hopefully the javadoc still says that getMarkupAttribute() is not very
efficient and that it should only be used in rare cases. The reason
why is because finding the tag in the markup is yet very inefficient
compared to using the tag parameter provided to many render XXX
functions. But I agree that in general the approach is what we want,
IMO just not the tag but the MarkupFragment (the piece of Markup that
is associated with the component). And because the Container (not the
Component though) does already have a MarkupStream, you wouldn't need
an additional variable. More importantly may be, MarkupFragment could
be transient as you only need to ask the markupcache to get a new
copy. MarkupFragment provides you access to the tag which than can be
modified. And at load time the MarkupFragment would be created and
kept in a meaningful structure (cache) to find it more efficiently.
The current implement is far from perfect. One more note: currently we
use resolvers which allow to augment or replace the strictly
hierarchical order of tags e.g. with a flat one (scan the mail archive
for people doing that). We'd need a similar flexibility to find the
tag in the markup. IMO that would be a more complete approach but it'd
be much more work.
As a side note: I'm not especially proud of that renderComponent code
everything that is related to it. It was more a quick hack to have a
fast result rather than an well thougt through approach. It was meant
to be replaced in 2.0 with what I described above. IMO we shouldn't
modify it a lot. It is like hacking a hack.
Juergen
On 6/8/06, Johan Compagner <[EMAIL PROTECTED]> wrote:
> Hi,
>
> i am looking at this code inside Component:
>
> public final ValueMap getMarkupAttributes()
> {
> MarkupStream markupStream = MarkupFragmentFinder.find(this);
> ValueMap attrs = new ValueMap(
> markupStream.getTag().getAttributes());
> attrs.makeImmutable();
> return attrs;
> }
>
> and:
>
> public final void renderComponent(final MarkupStream markupStream)
> {
> this.markupIndex = markupStream.getCurrentIndex();
>
> // Get mutable copy of next tag
> final ComponentTag openTag = markupStream.getTag();
> final ComponentTag tag = openTag.mutable();
>
> // Call any tag handler
> onComponentTag(tag);
>
>
> What i would like to do is change this behaviour and let the Component
> creates a copy of there own Tag inside itself (at construct time)
>
> so that getMarkupAttributes() is not immutable anymore.
> you can just do:
>
> mylabel.getMarkupAttributes().put("class", "mycssclass");
>
> instead of making a attribute modifer object with attribtue "class" and
> value "mycssclass" and then add that as a behaviour/attributemodifier on the
> component.
>
> so i want something like this: (all on Component)
>
>
> public Component(MarkupContainer<?> parent, final String id, final
> IModel<T> model)
> {
> if (parent == null)
> {
> if (!(this instanceof Page))
> {
> throw new WicketRuntimeException("component
> without a parent is not allowed.");
> }
> }
> this.parent = parent;
> setId(id);
>
> try
> {
> MarkupStream markupStream = MarkupFragmentFinder.find(this);
> tag = markupStream.getTag().mutable(); // GET the Tag out of the
> markup and make a copy.
> }
> catch(RuntimeException re)
> {
> throw new WicketRuntimeException("Couldn't find
> the markup of the component " + id + " in parent " +
> parent.getPageRelativePath ());
> }
> ........
>
>
> ComponentTag getTag() // Return the tag. Maybe not needed this method..
> {
> return tag;
> }
>
> public final ValueMap getMarkupAttributes()
> {
> return tag.getAttributes(); // Directly return the mutable tags
> attributes
> }
>
> public final void renderComponent(final MarkupStream markupStream)
> {
> this.markupIndex = markupStream.getCurrentIndex();
>
> final ComponentTag tag = getTag(); // Just use the mutable tag
> attributes.
>
> // Call any tag handler
> onComponentTag(tag);
> .................
>
>
> The only thing is that we then hold a reference to a Tag in every
> component..
> We don't need some AttributeModifiers then because you can do that directly.
> And we don't generate constant copies..
>
> what we also could do is not get a copy of the tag but just the attributes
> map.
> Then we don't hold the complete xml tree as a copy in mem.
>
> Then we just need to set those attributes in the component tag at render
> time.
> i guess this would be even much better.
>
> any other ideas?
>
> johan
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Wicket-develop mailing list
> Wicket-develop@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/wicket-develop
>
>
>
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