/* Copyright (c) 2006 Google Inc.
*
* 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
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using System.IO;
using System.Collections;
using System.Text;
using System.Xml;
using Google.GData.Client;
namespace Google.GData.Extensions{
/// <summary>
/// GData schema extension describing a nested entry link.
/// </summary>
public class EntryLink : IExtensionElement
{
/// <summary>holds the href property of the EntryLink element</summary>
protected string href;
/// <summary>holds the readOnlySet property of the EntryLink element</summary>
protected bool readOnly;
/// <summary>holds the AtomEntry property of the EntryLink element</summary>
protected AtomEntry entry;
private bool readOnlySet;
/// <summary>
/// Entry URI
/// </summary>
public string Href
{
get { return href; }
set { href = value; }
}
/// <summary>
/// Read only flag.
/// </summary>
public bool ReadOnly
{
get { return this.readOnly; }
set { this.readOnly = value; this.readOnlySet = true; }
}
/// <summary>
/// Nested entry (optional).
/// </summary>
public AtomEntry Entry
{
get { return entry; }
set { entry = value; }
}
#region EntryLink Parser
//////////////////////////////////////////////////////////////////////
/// <summary>parses an xml node to create an EntryLink object</summary>
/// <param name="node">entrylink node</param>
/// <param name="parser">AtomFeedParser to use</param>
/// <returns> the created EntryLink object</returns>
//////////////////////////////////////////////////////////////////////
public static EntryLink ParseEntryLink(XmlNode node, AtomFeedParser parser)
{
Tracing.TraceCall();
EntryLink link = null;
Tracing.Assert(node != null, "node should not be null");
if (node == null)
{
throw new ArgumentNullException("node");
}
object localname = node.LocalName;
if (localname.Equals(GDataParserNameTable.XmlEntryLinkElement))
{
link = new EntryLink();
if (node.Attributes != null)
{
if (node.Attributes[GDataParserNameTable.XmlAttributeHref] != null)
{
link.Href = node.Attributes[GDataParserNameTable.XmlAttributeHref].Value;
}
if (node.Attributes[GDataParserNameTable.XmlAttributeReadOnly] != null)
{
link.ReadOnly = node.Attributes[GDataParserNameTable.XmlAttributeReadOnly].Value.Equals("true");
}
}
if (node.HasChildNodes)
{
foreach (XmlNode entryChild in node.ChildNodes)
{
if (entryChild.LocalName == AtomParserNameTable.XmlAtomEntryElement &&
entryChild.NamespaceURI == BaseNameTable.NSAtom)
{
if (link.Entry == null)
{
XmlReader reader = new XmlNodeReader(entryChild);
parser.NewAtomEntry += new FeedParserEventHandler(link.OnParsedNewEntry);
parser.ParseEntry(reader);
}
else
{
throw new ArgumentException("Only one entry is allowed inside the g:entryLink");
}
}
}
}
}
return link;
}
//////////////////////////////////////////////////////////////////////
/// <summary>Event chaining. We catch this from the AtomFeedParser
/// we want to set this to our property, and do not add the entry to the collection
/// </summary>
/// <param name="sender"> the object which send the event</param>
/// <param name="e">FeedParserEventArguments, holds the feed entry</param>
/// <returns> </returns>
//////////////////////////////////////////////////////////////////////
internal void OnParsedNewEntry(object sender, FeedParserEventArgs e)
{
// by default, if our event chain is not hooked, add it to the collection
Tracing.TraceCall("received new item notification");
Tracing.Assert(e != null, "e should not be null");
if (e == null)
{
throw new ArgumentNullException("e");
}
if (e.CreatingEntry == false)
{
if (e.Entry != null)
{
// add it to the collection
Tracing.TraceMsg("\t new EventEntry found");
this.Entry = e.Entry;
e.DiscardEntry = true;
}
}
}
/////////////////////////////////////////////////////////////////////////////
#endregion
#region overloaded for persistence
//////////////////////////////////////////////////////////////////////
/// <summary>Returns the constant representing this XML element.</summary>
//////////////////////////////////////////////////////////////////////
public string XmlName
{
get { return GDataParserNameTable.XmlEntryLinkElement; }
}
/// <summary>
/// Used to save the EntryLink instance into the passed in xmlwriter
/// </summary>
/// <param name="writer">the XmlWriter to write into</param>
public void Save(XmlWriter writer)
{
if (Utilities.IsPersistable(this.Href) ||
this.readOnlySet ||
this.entry != null)
{
writer.WriteStartElement(BaseNameTable.gDataPrefix, XmlName, BaseNameTable.gNamespace);
if (Utilities.IsPersistable(this.Href))
{
writer.WriteAttributeString(GDataParserNameTable.XmlAttributeHref, this.Href);
}
if (this.readOnlySet)
{
writer.WriteAttributeString(GDataParserNameTable.XmlAttributeReadOnly, this.ReadOnly.ToString());
}
if (entry != null)
{
entry.SaveToXml(writer);
}
writer.WriteEndElement();
}
}
#endregion
}
}
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