in the code below, ViewContext vctx = (ViewContext) context;
should read: ViewContext vctx = (ViewContext) context.getInternalUserContext(); and this is fine, as long as the directive is being used with VelocityView. C > -----Original Message----- > From: Townson, Chris [mailto:[EMAIL PROTECTED] > Sent: 10 January 2007 09:31 > To: Velocity Users List > Subject: RE: VelocityView and toolbox - location of tool instance > > okay, I think I see why this doesn't work: > > the directive's init() does not receive the same context as > render() - at the point of init() we just have a standard > VelocityContext (it looks like the parser is just > initializing a tree at this point) > > ... only once we reach render, do we have the actual context: > if I move the code which retrieves the tool into the render > method, it works: > > 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); > } > > public boolean render(InternalContextAdapter context, > Writer writer, Node node) > throws IOException, ResourceNotFoundException, > ParseErrorException, > MethodInvocationException > { > try > { > MyTool tool = (MyTool) context.get("mytool"); > } > catch (Exception e) > { > // handle ClassCastException here > } > > 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; > } > } > } > > > -----Original Message----- > > From: Townson, Chris [mailto:[EMAIL PROTECTED] > > Sent: 09 January 2007 18:49 > > To: Velocity Users List > > Subject: RE: VelocityView and toolbox - location of tool instance > > > > 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 > > > > > > > > > > ******************************************************************************** DISCLAIMER: This e-mail is confidential and should not be used by anyone who is not the original intended recipient. 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