PlainXmlDeserializer.cs source code in C# .NET

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Code:

/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataWeb / Server / System / Data / Services / Serializers / PlainXmlDeserializer.cs / 1305376 / PlainXmlDeserializer.cs

                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//  
//      Provides a deserializer for plain XML content.
//  
// 
// @owner [....]
//--------------------------------------------------------------------- 

namespace System.Data.Services.Serializers
{
    using System; 
    using System.Data.Services.Common;
    using System.Data.Services.Parsing; 
    using System.Data.Services.Providers; 
    using System.Diagnostics;
    using System.IO; 
    using System.Text;
    using System.Xml;

    /// Provides a deserializer for plain XML content. 
    internal class PlainXmlDeserializer : Deserializer
    { 
        /// reader to read xml from the request stream 
        private readonly XmlReader xmlReader;
 
        /// Whether  is owned and should be disposed of.
        private readonly bool xmlReaderOwned;

        /// Properties already applied based on content 
        private readonly EpmContentDeSerializer.EpmAppliedPropertyInfo propertiesApplied;
 
        /// Prefix of the path to use in  
        private String currentPathPrefix;
 
        /// Initializes a new  for the specified stream.
        /// Input stream reader from which POX content must be read.
        /// Encoding to use for the stream (null to auto-discover).
        /// Data service for which the deserializer will act. 
        /// Indicates whether this is a PUT operation (rather than POST).
        /// Tracker to use for modifications. 
        internal PlainXmlDeserializer(Stream stream, Encoding encoding, IDataService dataService, bool update, UpdateTracker tracker) 
            : base(update, dataService, tracker)
        { 
            Debug.Assert(stream != null, "stream != null");
            this.xmlReader = XmlUtil.CreateXmlReader(stream, encoding);
            this.xmlReaderOwned = true;
        } 

        /// Initializes a new  based on the settings for another one. 
        /// Reader for content. 
        /// Parent deserializer.
        /// Properties already applied based on content 
        internal PlainXmlDeserializer(XmlReader reader, Deserializer deserializer, EpmContentDeSerializer.EpmAppliedPropertyInfo propertiesApplied)
            : base(deserializer)
        {
            Debug.Assert(reader != null, "reader != null"); 
            this.xmlReader = reader;
            Debug.Assert(propertiesApplied != null, "Requires valid collection for applied properties"); 
            this.propertiesApplied = propertiesApplied; 
            this.currentPathPrefix = String.Empty;
 
            // this.xmlReaderOwned = false;
        }

        /// Returns the content format for the deserializer. 
        protected override ContentFormat ContentFormat
        { 
            get 
            {
                return ContentFormat.PlainXml; 
            }
        }

        /// Applies properties from the reader to the specified resource. 
        /// Deserializer which is driving the .
        /// XmlReader to read from. 
        /// Type of resource. 
        /// Resource to set value on.
        /// Properties already applied based on content 
        /// current object count for this operation.
        /// 
        /// This method will end as soon as it find something that is not an
        /// XML element to process. 
        /// 
        internal static void ApplyContent(Deserializer deserializer, XmlReader reader, ResourceType resourceType, object resource, EpmContentDeSerializer.EpmAppliedPropertyInfo propertiesApplied, int currentObjectCount) 
        { 
            Debug.Assert(deserializer != null, "deserializer != null");
            Debug.Assert(reader != null, "reader != null"); 
            using (PlainXmlDeserializer xml = new PlainXmlDeserializer(reader, deserializer, propertiesApplied))
            {
                // Initialize the new deserializer instance with the current object count
                xml.UpdateObjectCount(currentObjectCount); 

                // load all the properties 
                xml.ApplyContent(xml.xmlReader, resourceType, resource); 

                // After all the properties have been loaded, initialize the current deserializer value with the object count 
                deserializer.UpdateObjectCount(xml.MaxObjectCount);
            }
        }
 
        /// 
        /// Converts the given value to the expected type as per XML serializer rules. 
        /// Make sure these rules are in [....] with PlainXmlSerializer. 
        /// 
        /// value to the converted 
        /// name of the property whose value is getting converted
        /// clr type to which the value needs to be converted to
        /// object which is in [....] with the properties type
        internal static object ConvertValuesForXml(object value, string propertyName, Type typeToBeConverted) 
        {
            Debug.Assert(WebUtil.IsPrimitiveType(typeToBeConverted), "WebUtil.IsPrimitiveType(typeToBeConverted)"); 
            Debug.Assert(value == null || value is string, "This method should be used only for converting string to a primitve value."); 

            string stringValue = value as string; 
            if (stringValue != null)
            {
                try
                { 
                    value = WebConvert.StringToPrimitive(stringValue, typeToBeConverted);
                } 
                catch (FormatException e) 
                {
                    throw DataServiceException.CreateBadRequestError(Strings.BadRequest_ErrorInConvertingPropertyValue(propertyName, typeToBeConverted), e); 
                }
            }

            return value; 
        }
 
        ///  
        /// Assumes the payload to represent a single object and processes accordingly
        ///  
        /// info about the object being created
        /// the newly formed object that the payload represents
        protected override object CreateSingleObject(SegmentInfo segmentInfo)
        { 
            Debug.Assert(
                segmentInfo.TargetKind == RequestTargetKind.OpenProperty || 
                segmentInfo.TargetKind == RequestTargetKind.ComplexObject || 
                segmentInfo.TargetKind == RequestTargetKind.Primitive,
                segmentInfo.TargetKind + " is one of open property; complex object; primitive -- otherwise the wrong serializer was chosen"); 

            if (!WebUtil.XmlReaderEnsureElement(this.xmlReader))
            {
                throw DataServiceException.CreateBadRequestError(Strings.PlainXml_PayloadLacksElement); 
            }
 
            if (HasNullAttributeWithTrueValue(this.xmlReader)) 
            {
                return null; 
            }

            string propertyName;
            if (segmentInfo.TargetKind == RequestTargetKind.OpenProperty) 
            {
                propertyName = this.xmlReader.LocalName; 
            } 
            else
            { 
                Debug.Assert(segmentInfo.ProjectedProperty != null, "segmentInfo.ProjectedProperty != null");
                Debug.Assert(
                    segmentInfo.ProjectedProperty.ResourceType.ResourceTypeKind != ResourceTypeKind.EntityType,
                    "entity types not expected in the PlainXmlDeserializer"); 

                propertyName = segmentInfo.ProjectedProperty.Name; 
                if (propertyName != this.xmlReader.LocalName) 
                {
                    throw DataServiceException.CreateBadRequestError( 
                        Strings.PlainXml_IncorrectElementName(propertyName, this.xmlReader.LocalName));
                }
            }
 
            object result = this.ReadPropertyWithType(this.xmlReader, propertyName, segmentInfo.ProjectedProperty);
            return result; 
        } 

        /// Provides an opportunity to clean-up resources. 
        /// 
        /// Whether the call is being made from an explicit call to
        /// IDisposable.Dispose() rather than through the finalizer.
        ///  
        protected override void Dispose(bool disposing)
        { 
            base.Dispose(disposing); 
            if (disposing && this.xmlReaderOwned)
            { 
                this.xmlReader.Close();
            }
        }
 
        /// 
        /// Get the resource referred by the uri in the payload 
        ///  
        /// resource referred by the uri in the payload.
        protected override string GetLinkUriFromPayload() 
        {
            if (!WebUtil.XmlReaderEnsureElement(this.xmlReader))
            {
                throw DataServiceException.CreateBadRequestError(Strings.PlainXml_PayloadLacksElement); 
            }
 
            string uri = null; 
            bool skipped;
            do 
            {
                skipped = false;
                switch (this.xmlReader.NodeType)
                { 
                    case XmlNodeType.Element:
                        string localName = this.xmlReader.LocalName; 
                        string elementNamespace = this.xmlReader.NamespaceURI; 
                        if ((elementNamespace != XmlConstants.DataWebMetadataNamespace && elementNamespace != XmlConstants.DataWebNamespace) ||
                            localName != XmlConstants.UriElementName) 
                        {
                            this.xmlReader.Skip();
                            skipped = true;
                            continue; 
                        }
 
                        if (uri != null) 
                        {
                            throw DataServiceException.CreateBadRequestError(Strings.BadRequest_MoreThanOneUriElementSpecified); 
                        }

                        uri = ReadElementString(this.xmlReader, localName);
                        if (String.IsNullOrEmpty(uri)) 
                        {
                            throw DataServiceException.CreateBadRequestError(Strings.BadRequest_MissingUriForLinkOperation); 
                        } 

                        break; 
                    default:
                        break;
                }
            } 
            while (skipped || this.xmlReader.Read());
 
            Debug.Assert( 
                this.xmlReader.NodeType != XmlNodeType.Element,
                "reader.NodeType != XmlNodeType.Element -- otherwise we should have kept processing"); 

            if (String.IsNullOrEmpty(uri))
            {
                throw DataServiceException.CreateBadRequestError(Strings.BadRequest_MissingUriForLinkOperation); 
            }
 
            return uri; 
        }
 
        /// 
        /// returns true if the null attribute is specified and the value is true
        /// 
        /// xml reader from which attribute needs to be read 
        /// true if the null attribute is specified and the attribute value is true
        private static bool HasNullAttributeWithTrueValue(XmlReader reader) 
        { 
            Debug.Assert(reader != null, "reader != null");
            Debug.Assert(reader.NodeType == XmlNodeType.Element, "reader.NodeType == XmlNodeType.Element"); 

            string elementValue = reader.GetAttribute(XmlConstants.AtomNullAttributeName, XmlConstants.DataWebMetadataNamespace);

            // If the null attribute is specified and the value is true, then set the property value to null, 
            // otherwise set the value to empty string
            if ((null != elementValue) && XmlConvert.ToBoolean(elementValue)) 
            { 
                string elementName = reader.LocalName;
                if (!reader.IsEmptyElement) 
                {
                    reader.Read();
                    if (reader.NodeType != XmlNodeType.EndElement)
                    { 
                        throw DataServiceException.CreateBadRequestError(
                            Strings.BadRequest_CannotSpecifyValueOrChildElementsForNullElement(elementName)); 
                    } 
                }
 
                return true;
            }

            return false; 
        }
 
        ///  
        /// Reads the value from the given element. This leaves the reader in the EndElement.
        ///  
        /// xml reader from which the value needs to be read
        /// name of the element whose value is getting read
        /// returns the xml string values as specified in the payload
        private static string ReadElementString(XmlReader reader, string elementName) 
        {
            Debug.Assert(reader != null, "reader != null"); 
            Debug.Assert(XmlNodeType.Element == reader.NodeType, "not positioned on Element"); 
            string elementValue = null;
 
            if (HasNullAttributeWithTrueValue(reader))
            {
                return null;
            } 
            else if (reader.IsEmptyElement)
            { 
                return String.Empty; 
            }
 
            StringBuilder builder = null;
            bool done = false;
            while (!done && reader.Read())
            { 
                switch (reader.NodeType)
                { 
                    case XmlNodeType.EndElement: 
                        done = true;
                        break; 
                    case XmlNodeType.CDATA:
                    case XmlNodeType.Text:
                    case XmlNodeType.SignificantWhitespace:
                        if (elementValue == null) 
                        {
                            elementValue = reader.Value; 
                        } 
                        else if (builder == null)
                        { 
                            string newValue = reader.Value;
                            builder = new StringBuilder(newValue.Length + elementValue.Length);
                            builder.Append(elementValue);
                            builder.Append(newValue); 
                        }
                        else 
                        { 
                            builder.Append(reader.Value);
                        } 

                        break;
                    case XmlNodeType.Comment:
                    case XmlNodeType.Whitespace: 
                        break;
 
                    #region XmlNodeType error 
                    case XmlNodeType.None:
                    case XmlNodeType.XmlDeclaration: 
                    case XmlNodeType.Attribute:
                    case XmlNodeType.EndEntity:
                    case XmlNodeType.EntityReference:
                    case XmlNodeType.Entity: 
                    case XmlNodeType.Document:
                    case XmlNodeType.DocumentType: 
                    case XmlNodeType.DocumentFragment: 
                    case XmlNodeType.Notation:
                    case XmlNodeType.ProcessingInstruction: 
                    default:
                        throw DataServiceException.CreateBadRequestError(Strings.BadRequest_InvalidValue(elementName));
                    #endregion
                } 
            }
 
            if (builder != null) 
            {
                elementValue = builder.ToString(); 
            }
            else if (elementValue == null)
            {
                elementValue = String.Empty; 
            }
 
            return elementValue; 
        }
 
        /// Applies properties from the reader to the specified resource.
        /// XmlReader to read from.
        /// Type of resource.
        /// Resource to set value on. 
        /// 
        /// This method will end as soon as it find something that is not an 
        /// XML element to process. 
        /// 
        private void ApplyContent(XmlReader reader, ResourceType resourceType, object resource) 
        {
            Debug.Assert(resourceType != null, "resourceType != null");
            Debug.Assert(resource != null, "resource != null");
 
            if (!WebUtil.XmlReaderEnsureElement(reader))
            { 
                return; 
            }
 
            this.RecurseEnter();
            bool skipped;
            do
            { 
                skipped = false;
                switch (reader.NodeType) 
                { 
                    case XmlNodeType.Element:
                        string localName = reader.LocalName; 
                        string elementNamespace = reader.NamespaceURI;
                        if (elementNamespace != XmlConstants.DataWebNamespace)
                        {
                            reader.Skip(); 
                            skipped = true;
                            continue; 
                        } 

                        this.ApplyProperty(reader, localName, resourceType, resource); 
                        break;
                    default:
                        break;
                } 
            }
            while (skipped || reader.Read()); 
 
            Debug.Assert(
                reader.NodeType != XmlNodeType.Element, 
                "reader.NodeType != XmlNodeType.Element -- otherwise we should have kept processing");
            this.RecurseLeave();
        }
 
        /// Applies a property from the reader to the specified resource.
        /// XmlReader to read from. 
        /// Name of property to set on the specified resource. 
        /// Type of resource.
        /// Resource to set value on. 
        private void ApplyProperty(XmlReader reader, string propertyName, ResourceType resourceType, object resource)
        {
            Debug.Assert(reader != null, "reader != null");
            Debug.Assert(propertyName != null, "propertyName != null"); 
            Debug.Assert(resourceType != null, "resourceType != null");
            Debug.Assert(resource != null, "resource != null"); 
 
            ResourceProperty property = resourceType.TryResolvePropertyName(propertyName);
            bool ignoreValue = false; 
            if (property == null)
            {
                if (resourceType.IsOpenType == false)
                { 
                    throw DataServiceException.CreateBadRequestError(Strings.BadRequest_InvalidPropertyNameSpecified(propertyName, resourceType.FullName));
                } 
            } 
            else
            { 
                if (this.Update && property.IsOfKind(ResourcePropertyKind.Key))
                {
                    ignoreValue = true;
                } 
            }
 
            object propertyValue = this.ReadPropertyWithType(reader, propertyName, property); 
            if (!ignoreValue)
            { 
                if (property == null)
                {
                    Deserializer.SetOpenPropertyValue(resource, propertyName, propertyValue, this.Service);
                } 
                else
                { 
                    Deserializer.SetPropertyValue(property, resource, propertyValue, this.ContentFormat, this.Service); 
                }
            } 
        }

        /// Gets the type attribute and resolves the type.
        /// reader from which type attribute needs to be read 
        /// resolved type
        private ResourceType ReadOpenPropertyTypeAttribute(XmlReader reader) 
        { 
            Debug.Assert(reader != null, "reader != null");
            string typeName = reader.GetAttribute(XmlConstants.AtomTypeAttributeName, XmlConstants.DataWebMetadataNamespace); 
            ResourceType resourceType = null;

            // If the type is not specified in the payload, we assume the type to be the expected type
            if (String.IsNullOrEmpty(typeName)) 
            {
                resourceType = ResourceType.PrimitiveStringResourceType; 
            } 
            else
            { 
                // try and resolve the name specified in the payload
                resourceType = WebUtil.TryResolveResourceType(this.Service.Provider, typeName);
                if (resourceType == null)
                { 
                    throw DataServiceException.CreateBadRequestError(Strings.BadRequest_InvalidTypeName(typeName));
                } 
 
                if (resourceType.ResourceTypeKind == ResourceTypeKind.EntityType)
                { 
                    throw DataServiceException.CreateBadRequestError(
                        Strings.PlainXml_EntityTypeNotSupported(resourceType.FullName));
                }
            } 

            return resourceType; 
        } 

        /// Reads a typed property from the specified XmlReader. 
        /// XmlReader to read from.
        /// Name of property to read.
        /// resourceProperty whose value is to be read.
        /// The instance read, possibly null. 
        private object ReadPropertyWithType(XmlReader reader, string propertyName, ResourceProperty resourceProperty)
        { 
            Debug.Assert(reader != null, "reader != null"); 
            Debug.Assert(propertyName != null, "propertyName != null");
            ResourceType propertyType = null; 

            // If this is a open property OR we do not have to do type conversion for primitive types,
            // read the type from the payload.
            bool readTypeFromWire = 
                resourceProperty == null ||
                (!this.Service.Configuration.EnableTypeConversion && resourceProperty.ResourceType.ResourceTypeKind == ResourceTypeKind.Primitive); 
 
            if (readTypeFromWire)
            { 
                propertyType = this.ReadOpenPropertyTypeAttribute(reader);
            }
            else
            { 
                propertyType = resourceProperty.ResourceType;
            } 
 
            if (this.propertiesApplied != null)
            { 
                this.propertiesApplied.AddPropertyToTypeMapItem(
                                            this.BuildPropertyPath(propertyName),
                                            propertyType.FullName);
            } 

            object propertyValue; 
            String appliedPropertyName = resourceProperty != null ? resourceProperty.Name : propertyName; 

            switch (propertyType.ResourceTypeKind) 
            {
                case ResourceTypeKind.ComplexType:
                    this.CheckAndIncrementObjectCount();
 
                    bool isNull = HasNullAttributeWithTrueValue(reader);
                    if (this.propertiesApplied != null) 
                    { 
                        this.propertiesApplied.AddAppliedProperty(this.BuildPropertyPath(appliedPropertyName), isNull);
                    } 

                    if (isNull)
                    {
                        propertyValue = null; 
                    }
                    else 
                    { 
                        propertyValue = this.Updatable.CreateResource(null, propertyType.FullName);
                        if (!reader.IsEmptyElement) 
                        {
                            // Step inside the complex type, apply its properties, and pop back out.
                            using (XmlReader propertyReader = reader.ReadSubtree())
                            { 
                                if (!WebUtil.XmlReaderEnsureElement(propertyReader))
                                { 
                                    throw DataServiceException.CreateBadRequestError( 
                                        Strings.PlainXml_PropertyLacksElement(propertyName));
                                } 

                                propertyReader.ReadStartElement();
                                String savedPath = this.currentPathPrefix;
                                this.currentPathPrefix = String.IsNullOrEmpty(this.currentPathPrefix) ? appliedPropertyName : this.currentPathPrefix + "/" + appliedPropertyName; 
                                ApplyContent(propertyReader, propertyType, propertyValue);
                                this.currentPathPrefix = savedPath; 
                            } 

                            Debug.Assert( 
                                reader.NodeType == XmlNodeType.EndElement,
                                "reader.NodeType == XmlNodeType.EndElement -- otherwise ReadSubtree left outer read in incorrect position.");
                        }
                    } 

                    break; 
                case ResourceTypeKind.EntityType: 
                    throw DataServiceException.CreateBadRequestError(
                        Strings.PlainXml_NavigationPropertyNotSupported(propertyName)); 
                default:
                    Debug.Assert(
                        propertyType.ResourceTypeKind == ResourceTypeKind.Primitive,
                        "property.TypeKind == ResourceTypeKind.Primitive -- metadata shouldn't return " + propertyType.ResourceTypeKind); 

                    propertyValue = ReadElementString(reader, propertyName); 
 
                    // We need to convert the type to the wire type. Conversion to the property type happens in Deserializer.SetValue method.
                    if (readTypeFromWire) 
                    {
                        propertyValue = PlainXmlDeserializer.ConvertValuesForXml(propertyValue, propertyName, propertyType.InstanceType);
                    }
 
                    if (this.propertiesApplied != null)
                    { 
                        this.propertiesApplied.AddAppliedProperty(this.BuildPropertyPath(appliedPropertyName), false); 
                    }
 
                    break;
            }

            return propertyValue; 
        }
 
        /// Gives an absolute property path based on current prefix 
        /// Name of property
        /// Absolute path to the property 
        private String BuildPropertyPath(String propertyName)
        {
            return String.IsNullOrEmpty(this.currentPathPrefix) ? propertyName : this.currentPathPrefix + "/" + propertyName;
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.


                        

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