Really Simple RSS (Yeah, I know)

Introduction

There are plenty of articles out there dealing with consuming RSS, but only a few dealing with making your own. Furthermore, every time I use the xsd.exe tool published by Microsoft, I find people who have never heard of it. Despite its limitations, it is a good tool that needs more mention.

One thing I would like to mention up front is that XML and XSD are usually camelCase and not pascalCase. Unfortunately, the xsd.exe tool generates a blind copy of casing. If you manually edit the generated *.cs file below, you can change the attributes and the casing to get pascalCase .NET code. The output will still be compliant camelCase RSS, i.e.

[System.Xml.Serialization.XmlElement("rss")]
public partial class RSS {
    ...

I don't use this method in this article, in favor of generatability. With that said, I humbly present a simple XSD file and some code which, when used, will make it really simple to add really simple syndication to your site.

Background

This Wikipedia Article on RSS is the best background, I think.

Code

I skipped a lot of the standards for RSS 2.0 to make life easier. If you find you need a field that the schema below doesn't provide, then add it and regenerate the class file. Basically, copy and paste the file below into a file on your machine called C:\RSS_20.xsd (chosen for the article's sake; change at will).

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
    elementFormDefault="unqualified" version="2.0.1.10">
    <xs:annotation>
        <xs:documentation>Simple XML Schema for RSS 2.0</xs:documentation>
    </xs:annotation>
    <xs:element name="rss">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="channel">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="title" type="xs:string" />
                            <xs:element name="link" type="xs:anyURI" />
                            <xs:element name="description" 
                                type="xs:string" />
                            <xs:element name="language" type="xs:string" />
                            <xs:element name="pubDate" type="xs:dateTime" />
                            <xs:element name="lastBuildDate" 
                                type="xs:dateTime" />
                            <xs:element name="docs" type="xs:string" />
                            <xs:element name="generator" type="xs:string" />
                            <xs:element name="managingEditor" 
                                type="xs:string" />
                            <xs:element name="webMaster" type="xs:string" />
                            <xs:element name="item" maxOccurs="unbounded">
                                <xs:complexType>
                                    <xs:sequence>
                                        <xs:element name="title" 
                                            type="xs:string" />
                                        <xs:element name="link" 
                                            type="xs:string" />
                                        <xs:element name="description" 
                                            type="xs:string" />
                                        <xs:element name="pubDate" 
                                            type="xs:dateTime" />
                                        <xs:element name="guid" 
                                            type="xs:string" />
                                    </xs:sequence>      
                                </xs:complexType> 
                            </xs:element>
                        </xs:sequence>    
                    </xs:complexType>   
                </xs:element>
            </xs:sequence>
            <xs:attribute name="version" type="xs:string"/>
        </xs:complexType>
    </xs:element>
</xs:schema>

Now the fun part. Run a Visual Studio command prompt. There should be a shortcut installed from the Start menu -> Visual Studio -> Visual Studio Tools. If you cannot find it, then just open a command prompt and change your path Environment Variable. While I cannot tell you what your path will be, the one on my current machine is C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727. Your mileage may vary. For those that don't know, the path command is SET PATH=C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin with no space between the equals.

• In the command prompt, type C: and press Enter
• In the command prompt, type cd\ and press Enter
• In the command prompt, type xsd.exe RSS_20.xsd -c /n:"My.Favorite.Namespace" and press Enter

You should now have a RSS_20.cs file created.

//--------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:2.0.50727.832
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//--------------------------------------------------------------------------

...
snip
...

Add the file to your favorite C# project in ASP.NET. Create a sample page with only the page load method wired up and add the code below.

private rss FakeRss(){
    rss someRss = new rss();
    someRss.version = "2.0";
    someRss.channel = new rssChannel();
    someRss.channel.description = "A nice description for the channel";
    someRss.channel.language = "en-us";
    someRss.channel.link = "http://www.erlglobal.com";
    someRss.channel.title = "The Title of my feed";
    someRss.channel.pubDate = DateTime.Now.ToUniversalTime();

    rssChannelItem channelItem = new rssChannelItem();
    channelItem.pubDate = DateTime.Now.ToUniversalTime();
    channelItem.title = "News Item Title";
    channelItem.link = "http://www.a.link.to.the.item";
    channelItem.guid = "Usually the link but make it unique";
    channelItem.description = "A Brief Summary";
    someRss.channel.item = new rssChannelItem[]{channelItem};

    return someRss;
}

protected void Page_Load(object sender, EventArgs e) {
    Response.Clear();
    Response.ContentType = "text/xml";
    Response.ContentEncoding = System.Text.Encoding.UTF8;
    XmlSerializer XML = new XmlSerializer(typeof(rss));
    xml.Serialize(Response.Output, FakeRss());
    Response.End();
}

There you go: an RSS feed that you can deliver from your own site, using a schema which can be validated against illustrating the xsd.exe tool.

Points of Interest

• The Specification
• The Wiki

History

• 9 October, 2007 -- Removed error in the *.xsd, thanks pzkpfw
• 5 October, 2007 -- Original version posted