MonoRail/Castle.MonoRail.Framework/JSGeneration/DynamicDispatching/JSGeneratorDispatcherBase.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 namespace Castle.MonoRail.Framework.JSGeneration.DynamicDispatching
  16 {
  17         using System;
  18
  19         /// <summary>
  20         /// Abstract class that contains the shared logic of JS Generation, separated from
  21         /// the various view engines implementations
  22         /// </summary>
  23         public abstract class JSGeneratorDispatcherBase : DynamicDispatcher
  24         {
  25                 private readonly IJSCodeGenerator codeGen;
  26                 private readonly IJSGenerator generator;
  27                 private readonly object[] elementExtensions;
  28
  29                 /// <summary>
  30                 /// Initializes a new instance of the <see cref="JSGeneratorDispatcherBase"/> class.
  31                 /// </summary>
  32                 /// <param name="codeGen">The code gen.</param>
  33                 /// <param name="generator">The generator.</param>
  34                 /// <param name="extensions">The extensions.</param>
  35                 /// <param name="elementExtensions">The element extensions.</param>
  36                 protected JSGeneratorDispatcherBase(IJSCodeGenerator codeGen, IJSGenerator generator, object[] extensions, object[] elementExtensions)
  37                         : base(generator, extensions)
  38                 {
  39                         this.codeGen = codeGen;
  40                         this.generator = generator;
  41                         this.elementExtensions = elementExtensions;
  42                 }
  43
  44                 /// <summary>
  45                 /// Gets the javascript code generator.
  46                 /// </summary>
  47                 /// <value>The code gen.</value>
  48                 public IJSCodeGenerator CodeGen
  49                 {
  50                         get { return codeGen; }
  51                 }
  52
  53                 /// <summary>
  54                 /// Executes an operation (totally late bound)
  55                 /// </summary>
  56                 /// <param name="method">The method.</param>
  57                 /// <param name="args">The args.</param>
  58                 /// <returns></returns>
  59                 protected object InternalInvoke(string method, params object[] args)
  60                 {
  61                         if (method == "el")
  62                         {
  63                                 AssertValidElementAccessor(args);
  64
  65                                 string root = args[0].ToString();
  66
  67                                 return CreateJSElementGeneratorProxy(codeGen, generator.CreateElementGenerator(root), elementExtensions);
  68                         }
  69
  70                         if (HasMethod(method))
  71                         {
  72                                 return Dispatch(method, args);
  73                         }
  74
  75                         return CreateNullGenerator();
  76                 }
  77
  78                 /// <summary>
  79                 /// Creates a null generator.
  80                 /// </summary>
  81                 /// <returns></returns>
  82                 protected abstract object CreateNullGenerator();
  83
  84                 /// <summary>
  85                 /// Creates a JS element generator.
  86                 /// </summary>
  87                 /// <param name="codeGen">The code gen.</param>
  88                 /// <param name="elementGenerator">The element generator.</param>
  89                 /// <param name="elementExtensions">The element extensions.</param>
  90                 /// <returns></returns>
  91                 protected abstract object CreateJSElementGeneratorProxy(IJSCodeGenerator codeGen, IJSElementGenerator elementGenerator, object[] elementExtensions);
  92
  93                 private static void AssertValidElementAccessor(object[] args)
  94                 {
  95                         if (args == null || args.Length != 1)
  96                         {
  97                                 throw new ArgumentException("el() method must be invoked with the element name as an argument");
  98                         }
  99                         if (args[0] == null)
 100                         {
 101                                 throw new ArgumentException("el() method invoked with a null argument");
 102                         }
 103                 }
 104         }
 105 }