MonoRail/Castle.MonoRail.Framework.Views.NVelocity/CustomDirectives/CaptureForDirective.cs

   1 // Copyright 2004-2008 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 using NVelocity.Runtime.Directive;
  16 using NVelocity.Context;
  17 using NVelocity.Runtime.Parser.Node;
  18
  19 namespace Castle.MonoRail.Framework.Views.NVelocity.CustomDirectives
  20 {
  21         using System;
  22         using System.IO;
  23         using System.Text;
  24
  25         public class CaptureForDirective : Directive
  26         {
  27                 /// <summary>
  28                 /// Render's the contents of the directive and store them in the context
  29                 /// variable so it can be referenced later on the template
  30                 ///
  31                 /// #capturefor(someId)
  32                 ///             Some content goes here
  33                 /// #end
  34                 ///
  35                 /// $someId
  36                 /// </summary>
  37                 public CaptureForDirective()
  38                 {
  39                 }
  40
  41                 public override bool Render(IInternalContextAdapter context, TextWriter writer, INode node)
  42                 {
  43                         if (node.ChildrenCount != 2)
  44                         {
  45                                 throw new MonoRailException("#capturefor directive expects an id attribute and a template block");
  46                         }
  47
  48                         ASTWord idNode = (ASTWord) node.GetChild(0);
  49                         ASTBlock bodyNode = (ASTBlock) node.GetChild(1);
  50
  51                         string id = idNode.Literal;
  52
  53                         StringWriter buffer = new StringWriter();
  54                         StringBuilder sb = buffer.GetStringBuilder();
  55
  56                         bodyNode.Render(context, buffer);
  57
  58                         String currentContent = context[id] as string;
  59
  60                         if( currentContent != null )
  61                         {
  62                                 sb.Append(currentContent);
  63                         }
  64
  65                         context[id] = sb.ToString();
  66
  67                         return true;
  68                 }
  69
  70                 public override String Name
  71                 {
  72                         get { return "capturefor"; }
  73                         set {  }
  74                 }
  75
  76                 public override DirectiveType Type
  77                 {
  78                         get { return DirectiveType.BLOCK; }
  79                 }
  80         }
  81 }