MonoRail/Castle.MonoRail.ActiveRecordSupport/ARFetchAttribute.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.ActiveRecordSupport
  16 {
  17         using System;
  18         using System.Reflection;
  19
  20         using Castle.MonoRail.Framework;
  21
  22         /// <summary>
  23         /// Mark a parameter with this attribute to instruct the <see cref="SmartDispatcherController" />
  24         /// to load an <c>ActiveRecord</c> instance of the parameter type, using the request parameter
  25         /// as the identifier.
  26         /// </summary>
  27         /// <remarks>
  28         /// The <see cref="ARFetchAttribute"/> only loads an instance
  29         /// based on the primary key value obtained from <see cref="IRailsEngineContext.Params"/>
  30         /// <para>For example:</para>
  31         /// <code>
  32         /// public class CustomerController : ARSmartDispatcherController
  33         /// {
  34         ///     public void UpdateCustomerLocation([ARFetch("customer.id")] Customer customer, [ARFetch("location.id")] Location location)
  35         ///     {
  36         ///       customer.Location = location;
  37         ///       customer.Save();
  38         ///
  39         ///       RedirectToAction("index");
  40         ///     }
  41         /// }
  42         /// </code>
  43         /// The code above assumes that you have the fields
  44         /// <c>customer.id</c> and <c>location.id</c> on the form being
  45         /// submitted.
  46         /// </remarks>
  47         [AttributeUsage(AttributeTargets.Parameter), Serializable]
  48         public class ARFetchAttribute : Attribute, IParameterBinder
  49         {
  50                 private String requestParameterName;
  51                 private bool create, required;
  52                 private String eager;
  53
  54                 /// <summary>
  55                 /// Constructs an <see cref="ARFetchAttribute"/>
  56                 /// specifying the parameter name and the create and require behavior
  57                 /// </summary>
  58                 /// <param name="requestParameterName">The parameter name to be read from the request</param>
  59                 /// <param name="create"><c>true</c> if you want an instance even when the record is not found</param>
  60                 /// <param name="required"><c>true</c> if you want an exception if the record is not found</param>
  61                 public ARFetchAttribute(String requestParameterName, bool create, bool required) : base()
  62                 {
  63                         this.requestParameterName = requestParameterName;
  64                         this.create = create;
  65                         this.required = required;
  66                 }
  67
  68                 /// <summary>
  69                 /// Constructs an <see cref="ARFetchAttribute"/> using the
  70                 /// parameter name as the <see cref="ARFetchAttribute.RequestParameterName"/>
  71                 /// </summary>
  72                 public ARFetchAttribute() : this(null, false, false)
  73                 {
  74                 }
  75
  76                 /// <summary>
  77                 /// Constructs an <see cref="ARFetchAttribute"/> specifing the
  78                 /// parameter name
  79                 /// <seealso cref="ARFetchAttribute.RequestParameterName"/>
  80                 /// </summary>
  81                 public ARFetchAttribute(String requestParameterName) : this(requestParameterName, false, false)
  82                 {
  83                 }
  84
  85                 /// <summary>
  86                 /// Constructs an <see cref="ARFetchAttribute"/> using the
  87                 /// parameter name as the <see cref="ARFetchAttribute.RequestParameterName"/>
  88                 /// and the create and require behavior
  89                 /// </summary>
  90                 /// <param name="create"><c>true</c> if you want an instance even when the record is not found</param>
  91                 /// <param name="require"><c>true</c> if you want an exception if the record is not found</param>
  92                 public ARFetchAttribute(bool create, bool require) : this(null, create, require)
  93                 {
  94                 }
  95
  96                 /// <summary>
  97                 /// The parameter name to be read from the request. The parameter value will
  98                 /// be used as the primary key value to load the target object instance.
  99                 /// </summary>
 100                 public String RequestParameterName
 101                 {
 102                         get { return requestParameterName; }
 103                         set { requestParameterName = value; }
 104                 }
 105
 106                 /// <summary>
 107                 /// When set to <c>true</c> an instance of
 108                 /// the target type will be created if the record
 109                 /// is not found. The default is <c>false</c>.
 110                 /// </summary>
 111                 public bool Create
 112                 {
 113                         get { return create; }
 114                         set { create = value; }
 115                 }
 116
 117                 /// <summary>
 118                 /// When set to <c>true</c>, an exception will be thrown
 119                 /// if the record specified is not found. The default is <c>false</c>.
 120                 /// </summary>
 121                 public bool Required
 122                 {
 123                         get { return required; }
 124                         set { required = value; }
 125                 }
 126
 127                 /// <summary>
 128                 /// Comma-separated list of lazy associations to eager-fetch, when loading the ActiveRecord object.
 129                 /// </summary>
 130                 public String Eager
 131                 {
 132                         get { return eager; }
 133                         set { eager = value; }
 134                 }
 135
 136                 public virtual int CalculateParamPoints(SmartDispatcherController controller, ParameterInfo parameterInfo)
 137                 {
 138                         String paramName = RequestParameterName != null ? RequestParameterName : parameterInfo.Name;
 139
 140                         return controller.Request.Params.Get(paramName) != null ? 10 : 0;
 141                 }
 142
 143                 public virtual object Bind(SmartDispatcherController controller, ParameterInfo parameterInfo)
 144                 {
 145                         ARFetcher fetcher = new ARFetcher(controller.Binder.Converter);
 146
 147                         return fetcher.FetchActiveRecord(parameterInfo, this, controller.Request);
 148                 }
 149         }
 150 }