yep - I was surprised, too.
I made an assumption about the context provided to the directive's render()
method (InternalContextAdapter) - that it was basically the context being used
to render the current template in which the directive was invoked ... however,
this does not appear to be the case. In fact, on close examination, it does not
even appear to contain or provide a reference to this context ... which seems
strange to me.
It must surely be possible to retrieve objects from the context with which the
current template is being merged from a directive's render() method ... the
question is "how?" I get the feeling that I must be missing something very
obvious in my code. Here is what I am trying to do, slightly abbreviated:
public class CustomDirective extends InputBase
{
public String getName()
{
return "custom";
}
public int getType()
{
return LINE;
}
public void init(RuntimeServices rsvc, InternalContextAdapter context,
Node node) throws TemplateInitException
{
super.init(rsvc, context, node);
try
{
MyTool tool = (MyTool) context.get("mytool");
}
catch (Exception e)
{
throw new TemplateInitException(e.getMessage(),
context.getCurrentTemplateName(),
node.getColumn(),
node.getLine());
}
}
public boolean render(InternalContextAdapter context, Writer writer, Node
node)
throws IOException, ResourceNotFoundException, ParseErrorException,
MethodInvocationException
{
if (tool != null)
{
try
{
String arg0 = (String) node.jjtGetChild(0).value(context);
Map arg1 = (Map) node.jjtGetChild(1).value(context);
ViewContext vctx = (ViewContext) context;
HttpServletRequest request = vctx.getRequest();
MyObject obj = tool.getMyObject(arg0, arg1, request);
Context ctx = new VelocityContext();
ctx.put("this", obj);
Template template = rsvc.getTemplate(obj.getTemplate());
template.merge(ctx, writer);
return true;
}
catch (Exception e)
{
return false;
}
}
else
{
return false;
}
}
}
this would go with a toolbox that looked something like:
<?xml version="1.0" encoding="UTF-8"?>
<toolbox>
<tool>
<key>mytool</key>
<scope>request</scope>
<class>foo.bar.MyTool</class>
</tool>
</toolbox>
and the instance of "MyObject" knows it's own template name and has a template
like this:
<ul>
<li>$this.property</li>
<li>$this.anotherProperty</li>
<!-- ... and so on ... -->
</ul>
Any suggestions / pointers / explanations of why this doesn't work would be
much appreciated.
Cheers,
Chris
> -----Original Message-----
> From: Nathan Bubna [mailto:[EMAIL PROTECTED]
> Sent: 04 January 2007 19:03
> To: Velocity Users List
> Subject: Re: VelocityView and toolbox - location of tool instance
>
> I'm a little surprised that the method you tried is failing. I
> haven't written many custom directives though, so i'm not sure how to
> help. Does anyone else out there know why the context provided to
> the directive wouldn't have access to the tools?
>
> That said, where instantiated tools is kept varies according to the
> scope. Application scoped tools are currently kept in a private
> HashMap in ServletToolboxManager. Session-scoped tools are kept in a
> HashMap placed into the user's session attributes. Both application
> and session tools are copied into the toolbox Map for the request,
> where they are joined by the freshly-instantiated request tools. The
> toolbox Map is then fed to the ChainedContext for the request. Which,
> i would have thought, ought to be accessible from the directive, since
> that is the context merged with the requested template.
>
> On 1/4/07, Townson, Chris <[EMAIL PROTECTED]> wrote:
> > Hi,
> >
> > I think this is a simple question ... although I could be
> having one of those winter, late-afternoon brain-dead moments ...
> >
> > Whereabouts exactly are tool class instances kept once they
> have been initialized when using VelocityView and
> toolbox.xml? In other words, from where and how does one
> obtain a reference to that tool instance (in another class,
> not in a template)?
> >
> > For example, if I have a custom directive and want to
> retrieve a previously initialized instance of an
> application-scope tool, how would I do this?
> >
> > Initially I thought that this would be achieved in the
> following way:
> >
> > in the toolbox:
> > <tool>
> > <key>myTool</key>
> > <scope>application</scope>
> > <class>com.foo.MyReallyGroovyTool</class>
> > </tool>
> >
> > in a directive:
> > public CustomDirective extends InputBase {
> > ...
> >
> > public void init(RuntimeServices rsvc,
> InternalContextAdapter context, Node node) throws
> TemplateInitException {
> > MyReallGroovyTool tool = (MyReallyGroovyTool)
> context.get("myTool");
> > }
> >
> > ...
> > }
> >
> >
> > but now I'm thinking this is not correct (and trying this
> way fails) ...
> >
> > Cheers,
> >
> > Chris
> >
> >
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