DotText实现支持自动发现服务接口

目标：使用Live Writer添加Dottext Blog帐号时支持自动发现webservice接口。实现后的添加只要一个步骤：输入blog地址，例如http://blogs.impx.net/dragonimp和blog帐号密码，点下一步自动配置service的api，完成即可。

实现：根据自动发现接口协议，实现对Dottext blog的service api的自动发现。

1、首先在default.aspx中增加link：

<link id="RSDLink" title="rsd" type="application/rsd+xml" rel="edituri" runat="Server"/>

2、在DottextMasterPage.cs中增加地址设置

RSDLink.Attributes.Add("href",CurrentBlog.FullyQualifiedUrl + "rsd.aspx");

3、在web.config中增加rsd.aspx的处理引擎

<HttpHandler pattern="/rsd/.aspx$" type="Dottext.Common.Syndication.RsdHandler,Dottext.Common"??? handlerType="Direct" />

4、实现RsdHandler类和RsdWriter（采用Rss的写法并继承原有的BaseSyndicationHandler类）

/*
using something needed...
Description:Rsd handler for DotText metaweblog api
Author:dragonimp 2009.1.11
http://www.impx.net?http://blogs.impx.net/dragonimp

*/

namespace Dottext.Common.Syndication
{
??? class RsdWriter : System.Xml.XmlTextWriter
??? {
??????? private StringWriter _sw = null;
??????? protected BlogConfig config;

??????? public RsdWriter(): this(new StringWriter())
??????? {
??????? }

??????? public RsdWriter(System.IO.Stream stream,Encoding encoding) : base(stream,encoding)
??????? {
??????? }

??????? public RsdWriter(StringWriter sw): base(sw)
??????? {
??????????? _sw = sw;
??????????? config = Dottext.Framework.Configuration.Config.CurrentBlog();
??????? }

??????? public StringWriter StringWriter
??????? {
??????????? get
??????????? {
??????????????? Build();
??????????????? return _sw;
??????????? }
??????? }

??????? public string GetXml
??????? {
??????????? get { return this.StringWriter.ToString(); }
??????? }

??????? private void Build()
??????? {
??????????? //this.Formatting = System.Xml.Formatting.Indented;
?????????? // this.WriteStartDocument();
??????????? this.WriteStartElement("rsd");
??????????? this.WriteAttributeString("version","1.0");
??????????? this.WriteStartElement("servie");
??????????? this.WriteElementString("engineName","DotText Rsd service 1.0 by dragonimp");
??????????? //this.WriteEndElement();//enginename
??????????? this.WriteElementString("engineLink",config.FullyQualifiedUrl + "rsd.aspx");
??????????? //this.WriteEndElement();//enginelink
??????????? this.WriteElementString("homePageLink",config.FullyQualifiedUrl);
??????????? //this.WriteEndElement();//homepagelinke???????????
??????????? this.WriteStartElement("apis");
??????????? this.WriteStartElement("api");
??????????? this.WriteAttributeString("name","MetaWeblog");
??????????? this.WriteAttributeString("preferred","true");
??????????? this.WriteAttributeString("apiLink",config.FullyQualifiedUrl + @"services/metablogapi.aspx");
??????????? this.WriteAttributeString("blogID",config.UserName);
??????????? this.WriteEndElement();//api
??????????? this.WriteEndElement();//apis
??????????? this.WriteEndElement();//service
??????????? this.WriteEndElement();//rsd
?????????? //? this.WriteEndDocument();//
??????? }
??? }

??? class RsdHandler : Dottext.Framework.Syndication.BaseSyndicationHandler
??? {
??????? public RsdHandler() { }
??????? private string key = "IndividualMainFeed_Rsd:FQU{0}";

??????? protected override string CacheKey()
??????? {
??????????? return string.Format(key,CurrentBlog.FullyQualifiedUrl);
??????? }
??????? protected override void Cache(CachedFeed feed)
??????? {
??????????? Context.Cache.Insert(CacheKey(),feed,null,DateTime.Now.AddSeconds((double)Dottext.Common.Data.CacheTime.Medium),TimeSpan.Zero);
??????? }
??????? protected override CachedFeed BuildFeed()
??????? {
??????????? this.key += "BlogID_Rsd" + CurrentBlog.BlogID.ToString();
??????????? CachedFeed feed = new CachedFeed();
??????????? feed.LastModified = this.ConvertLastUpdatedDate(CurrentBlog.LastUpdated);

??????????? RsdWriter rsdwriter = new RsdWriter();
??????????? feed.Xml=rsdwriter.GetXml;
??????????? return feed;
??????? }
??? }
}

参考文章：

http://www.tiray.net/post/Really-Simple-Discovery.aspx
http://cyber.law.harvard.edu/blogs/gems/tech/rsd.html