1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Http.Controllers;
using System.Web.Http.Metadata;
using System.Web.Http.Validation;
using System.Web.Http.ValueProviders;
using System.Web.Http.ValueProviders.Providers;
namespace System.Web.Http.ModelBinding
{
/// <summary>
/// Describes a parameter that gets bound via ModelBinding.
/// </summary>
public class ModelBinderParameterBinding : HttpParameterBinding
{
private readonly ValueProviderFactory[] _valueProviderFactories;
private readonly ModelBinderProvider _modelBinderProvider;
// Cache information for ModelBindingContext.
private ModelMetadata _metadataCache;
private ModelValidationNode _validationNodeCache;
public ModelBinderParameterBinding(HttpParameterDescriptor descriptor,
ModelBinderProvider modelBinderProvider,
IEnumerable<ValueProviderFactory> valueProviderFactories)
: base(descriptor)
{
if (modelBinderProvider == null)
{
throw Error.ArgumentNull("modelBinderProvider");
}
if (valueProviderFactories == null)
{
throw Error.ArgumentNull("valueProviderFactories");
}
_modelBinderProvider = modelBinderProvider;
_valueProviderFactories = valueProviderFactories.ToArray();
}
public IEnumerable<ValueProviderFactory> ValueProviderFactories
{
get { return _valueProviderFactories; }
}
public ModelBinderProvider ModelBinderProvider
{
get { return _modelBinderProvider; }
}
public override Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider, HttpActionContext actionContext, CancellationToken cancellationToken)
{
string name = Descriptor.ParameterName;
ModelBindingContext ctx = GetModelBindingContext(metadataProvider, actionContext);
IModelBinder binder = this._modelBinderProvider.GetBinder(actionContext, ctx);
bool haveResult = binder.BindModel(actionContext, ctx);
object model = haveResult ? ctx.Model : Descriptor.DefaultValue;
actionContext.ActionArguments.Add(name, model);
return TaskHelpers.Completed();
}
private ModelBindingContext GetModelBindingContext(ModelMetadataProvider metadataProvider, HttpActionContext actionContext)
{
string name = Descriptor.ParameterName;
Type type = Descriptor.ParameterType;
string prefix = Descriptor.Prefix;
IValueProvider vp = CreateValueProvider(this._valueProviderFactories, actionContext);
if (_metadataCache == null)
{
Interlocked.Exchange(ref _metadataCache, metadataProvider.GetMetadataForType(null, type));
}
ModelBindingContext ctx = new ModelBindingContext()
{
ModelName = prefix ?? name,
FallbackToEmptyPrefix = prefix == null, // only fall back if prefix not specified
ModelMetadata = _metadataCache,
ModelState = actionContext.ModelState,
ValueProvider = vp
};
if (_validationNodeCache == null)
{
Interlocked.Exchange(ref _validationNodeCache, ctx.ValidationNode);
}
else
{
ctx.ValidationNode = _validationNodeCache;
}
return ctx;
}
// Instantiate the value providers for the given action context.
private static IValueProvider CreateValueProvider(ValueProviderFactory[] factories, HttpActionContext actionContext)
{
if (factories.Length == 1)
{
return factories[0].GetValueProvider(actionContext);
}
IValueProvider[] providers = Array.ConvertAll(factories, f => f.GetValueProvider(actionContext));
return new CompositeValueProvider(providers);
}
}
}
|
