aspnetcore/src/Microsoft.AspNet.Mvc.ModelBinding/ModelBindingContext.cs

// Copyright (c) Microsoft Open Technologies, Inc.
// All Rights Reserved
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
// WITHOUT LIMITATION ANY IMPLIED WARRANTIES OR CONDITIONS OF
// TITLE, FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABLITY OR
// NON-INFRINGEMENT.
// See the Apache 2 License for the specific language governing
// permissions and limitations under the License.

using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using Microsoft.AspNet.Http;

namespace Microsoft.AspNet.Mvc.ModelBinding
{
    public class ModelBindingContext
    {
        private string _modelName;
        private ModelStateDictionary _modelState;
        private Dictionary<string, ModelMetadata> _propertyMetadata;
        private ModelValidationNode _validationNode;

        public ModelBindingContext()
        {
        }

        // copies certain values that won't change between parent and child objects,
        // e.g. ValueProvider, ModelState
        public ModelBindingContext(ModelBindingContext bindingContext)
        {
            if (bindingContext != null)
            {
                ModelState = bindingContext.ModelState;
                ValueProvider = bindingContext.ValueProvider;
                MetadataProvider = bindingContext.MetadataProvider;
                ModelBinder = bindingContext.ModelBinder;
                ValidatorProviders = bindingContext.ValidatorProviders;
                HttpContext = bindingContext.HttpContext;
            }
        }

        public object Model
        {
            get
            {
                EnsureModelMetadata();
                return ModelMetadata.Model;
            }
            set
            {
                EnsureModelMetadata();
                ModelMetadata.Model = value;
            }
        }

        public ModelMetadata ModelMetadata { get; set; }

        public string ModelName
        {
            get
            {
                if (_modelName == null)
                {
                    _modelName = String.Empty;
                }
                return _modelName;
            }
            set { _modelName = value; }
        }

        [SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly", Justification = "This is writeable to support unit testing")]
        public ModelStateDictionary ModelState
        {
            get
            {
                if (_modelState == null)
                {
                    _modelState = new ModelStateDictionary();
                }
                return _modelState;
            }
            set { _modelState = value; }
        }

        public Type ModelType
        {
            get
            {
                EnsureModelMetadata();
                return ModelMetadata.ModelType;
            }
        }

        public bool FallbackToEmptyPrefix { get; set; }

        public HttpContext HttpContext { get; set; }

        public IValueProvider ValueProvider
        {
            get;
            set;
        }

        public IModelBinder ModelBinder
        {
            get;
            set;
        }

        public IModelMetadataProvider MetadataProvider
        {
            get;
            set;
        }

        public IEnumerable<IModelValidatorProvider> ValidatorProviders
        {
            get;
            set;
        }

        public IDictionary<string, ModelMetadata> PropertyMetadata
        {
            get
            {
                if (_propertyMetadata == null)
                {
                    _propertyMetadata = ModelMetadata.Properties.ToDictionary(m => m.PropertyName, StringComparer.OrdinalIgnoreCase);
                }

                return _propertyMetadata;
            }
        }

        public ModelValidationNode ValidationNode
        {
            get
            {
                if (_validationNode == null)
                {
                    _validationNode = new ModelValidationNode(ModelMetadata, ModelName);
                }
                return _validationNode;
            }
            set { _validationNode = value; }
        }

        private void EnsureModelMetadata()
        {
            if (ModelMetadata == null)
            {
                throw new InvalidOperationException(Resources.ModelBindingContext_ModelMetadataMustBeSet);
            }
        }
    }
}