MonoRail/Castle.MonoRail.Views.Brail/IgnoreNull.cs

   1 // Copyright 2004-2007 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.Views.Brail
  16 {
  17         using System;
  18         using System.Collections.Generic;
  19         using Boo.Lang;
  20
  21         public class IgnoreNull : IQuackFu
  22         {
  23                 private readonly object target;
  24
  25                 public IgnoreNull(object target)
  26                 {
  27                         this.target = target;
  28                 }
  29
  30                 public object QuackGet(string name, object[] parameters)
  31                 {
  32                         if (name == "_IsIgnoreNullReferencingNotNullObject_")
  33                                 return target != null;
  34
  35                         if (target == null)
  36                                 return this;
  37                         object value;
  38                         if (IsNullOrEmpty(parameters))
  39                                 value = ExpandDuckTypedExpressions_WorkaroundForDuplicateVirtualMethods.GetProperty(target, name);
  40                         else
  41                                 value = ExpandDuckTypedExpressions_WorkaroundForDuplicateVirtualMethods.GetSlice(target, name, parameters);
  42                         return new IgnoreNull(value);
  43                 }
  44
  45                 private static bool IsNullOrEmpty(object[] parameters)
  46                 {
  47                         return parameters == null || parameters.Length == 0;
  48                 }
  49
  50                 public object QuackSet(string name, object[] parameters, object obj)
  51                 {
  52                         if (target == null)
  53                                 return this;
  54                         if (IsNullOrEmpty(parameters))
  55                                 ExpandDuckTypedExpressions_WorkaroundForDuplicateVirtualMethods.SetProperty(target, name, obj);
  56                         else
  57                                 ExpandDuckTypedExpressions_WorkaroundForDuplicateVirtualMethods.SetSlice(target, name, GetParameterArray(parameters, obj));
  58                         return this;
  59                 }
  60
  61                 private static object[] GetParameterArray(object[] parameters, object obj)
  62                 {
  63                         List<object> args = new List<object>(parameters);
  64                         args.Add(obj);
  65                         return args.ToArray();
  66                 }
  67
  68                 public object QuackInvoke(string name, object[] args)
  69                 {
  70                         if (target == null)
  71                                 return this;
  72                         object value = ExpandDuckTypedExpressions_WorkaroundForDuplicateVirtualMethods.Invoke(target, name, args);
  73                         return new IgnoreNull(value);
  74                 }
  75
  76                 public override string ToString()
  77                 {
  78                         if(target == null)
  79                                 return string.Empty;
  80                         return target.ToString();
  81                 }
  82
  83                 public static bool AreEqual(object left, object right)
  84                 {
  85                         IgnoreNull temp = left as IgnoreNull;
  86                         if (temp != null)
  87                                 left = temp.target;
  88                         temp = right as IgnoreNull;
  89                         if (temp != null)
  90                                 right = temp.target;
  91                         return Equals(left, right);
  92                 }
  93         }
  94 }