"William C. Robertson" wrote:
> Hello all,
>
> <xtag:context> does not seem to behave the same as it's cousin
> <xtag:forEach>. For the same path, forEach works but context doesn't. Is
> there something I'm missing?
Do you have any examples? I'm not sure what sort of behaviour your expecting to
be the same.
Originally we had only <xtags:forEach> which would iterate over a node set, and
didn't really need <xtags:context> as you could use an <xtags:forEach> on a
single node to change the context. However, it could be confusing to a page
developer as the forEach implied the author expected a multiple node set. Hence
the use of <xtags:context> for selecting a single node:
<xtags:parse>
<foo>
<bar>
<description>Some text</description>
</bar>
</foo>
</xtags:parse>
<xtags:forEach select="/foo/bar">
<xtags:valueOf select="description"/>
</xtags:forEach>
<xtags:context select="/foo/bar">
<xtags:valueOf select="description"/>
</xtags:context>
...the description will be output the same twice.
However, the forEach tag will always have a single node as the context in the
body, whereas <xtags:context> may set a list of nodes.
It's also useful when you have a dom4j Document object from somewhere else:
<% Document doc = myBean.getADocument(); %>
<xtags:context context="doc" select="/">
...
</xtags:context>
(although it looks as though this hasn't been fully implemented yet.. the
"context" attribute is listed in the TLD, but has no setter in the ContextTag
class. James S?)
> <xtag:variable> will return "an Object or List" if "node" is not specified.
> Is the list a list in the sense of a "linkedList" or part of the io package?
> Where can I find out about how to use it?
It'll be a java.util.List (is that right James S?). You can specify the type of
the variable to be "string" (which creates a java.lang.String object with the
value of the node(s), "node" which returns an org.dom4j.Node (useful for further
dom4j API manipulation, or setting a context later), or if you specify something
else, you'll get a java.util.List of Nodes. If you don't specify a type, you'll
get the textual String value.
<xtags:forEach select="//foo">
<xtags:variable id="attr" select="@attr"/>
The attribute value is <%=attr%>. That's <%=attr%> I say.
</xtags:forEach>
Very useful if you need to use the value of a node as a parameter to another
custom tag (as you can't use custom tags here), and to reduce the verbosity of a
page.
James
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