[Network] comprehensive introduction to blog and RSS

Comprehensive introduction to blog and RSS
Original: Aaron skonnard
Translation: northtibet
Source: msdn magazine Apr. 2004 (the XML files)
What is a blog?

"Blog" is short for Web Log (this is also called a blog in mainland China )). It is an intermediary between the author and the reader to interact in the log style. In the software community, people share ideas and ideas in the form of online blogs. For example, http://blogs.msdn.com is a blogging on msdn.

What is the easiest way to create a website?

The easiest way to create your own blog is to register a new user at a site like blogger.com, which provides a Web interface for creating a custom blog, and you can use the created network records immediately. There are many sites similar to blogger.com, all of which provide support for the characteristics of the website. If you want to control the basic structure of your website or create a website service system on your server. You can choose one of the following most popular business products: Radio userland, Manila, and movable type. Some easy-to-use. Net blog applications are available for free. The most popular ones are. Text and dasblog. You only need to download them and install and set them according to the installation instructions. A running wangzhi service system can be established in minutes.
Functionally, these two. Net-based wangzhi application systems are comparable. The main difference is. text requires a database, SQL Server, or MSDE, while dasblog stores all information in XML files (based on the blogx framework created by some original Microsoft developers). Another difference is that. text in a single installation configuration can support multiple network records (such as the current http://blogs.msdn.com), and dasblog to support multiple network records, must be installed multiple times. But dasblog has a very prominent feature, that is, "mail to weblog", which allows you to publish new information through mail.
The new msdn wangzhi service station and PDC bloggers are both good places to start searching for software development topics. You only need to browse one of these sites to read their aggregated predefined content. The pre-prepared abstract will reveal many personal notes to you, and gradually you will naturally find some content that you prefer to read. In this way, you can directly reserve your favorite personal blog abstract.
For the blogs devoted to XML and web services, please refer to the list on the msdn Web Services Developer Center. I personally spend a lot of time on these websites.

What is feed (hereinafter referred to as feed) and how to reserve it?

Wangzhi provides a feed for its content in the form of an RSS document, which can be obtained through a well-known URL. An RSS document is an XML file that contains a large number of discrete news items, such as entries in a blog (see Figure 1 for an RSS feed example ). Because RSS is an XML file, it is easy to be used by other programs.
RSS aggregator is a program that reads RSS documents and displays news items. Most aggregators only need to enter the rss url to make the pre-feed possible.
RSS makes it easy to read online logs. Most developers who frequently read the website use a certain type of aggregator to help them effectively filter the abstract content. The aggregators make it feel like reading emails, because they highlight news items and buffer them for offline reading (see figure 2 ).
Some online RSS aggregators also bundle RSS feeds to a separate website. It is easy to set and can access your abstract content from any computer. Of course, its disadvantage is also obvious, that is, the connection must always be maintained during reading.
RSS is the root of wangzhi becoming a powerful new form of information exchange. Before the advent of wangzhi, most developers usually spend a lot of time filtering out annoying irrelevant information to find the desired content.
Wangzhi allows the reader to select the abstract to be read and give control to the reader, so as to effectively build their own personalized content stream.
Other types of sites can also use RSS to aggregate content. For example, most mainstream news sites, including wired, CNET, Yahoo, and news, provide RSS feeds. Visit blogdigger and syndic8. You can find some sites that support RSS.
Microsoft's msdn provides RSS feeds to aggregate the technical content newly added to the site. The just published abstract of msdn is a primary method for keeping msdn new articles and downloads. Even msdn magazine (msdn magazine) has its own RSS feed! Can book: http://msdn.microsoft.com/msdnmag/rss/recent.xml get monthly updates to view what's going on in this period? There are currently many RSS aggregators to choose from, and a fairly complete list can be found on the http://blogs.law.harvard.edu/tech/directory/5/aggregators. Some of them are online aggregators, while others are desktop applications. Some of them are free of charge, and others need to be paid for use.

Which RSS version is the most common?

The answer to this question depends on who you are asking. There are many RSS versions, including 0.90, 0.91, 0.92, 0.93, 0.94, 1.0, and 2.0. Figuring out the differences between these versions is one of the greatest challenges. To understand them, you need to understand their historical background. Netscape created the first version of RSS 0.90. The initial name is "RDF Site Summary" or "rich site summary" (the former is the official name in the Specification ). Netscape creates RSS 0.90 for its web portal. At this time, others see the potential of RSS. Userland software is one of the first business users to use RSS for their online business products.
Version 0.90 is largely based on W3C Resource Description Framework (RDF ). Many people think that RDF is too complex, so we recommend a free simplified version 0.91. This task happens to be assigned to userland software. Userland software continues to develop simplified RSS versions, including 0.92, 0.93, and 0.94. To emphasize its simplified work, they set the full name of RSS as "Really Simple Syndication ".
While userland software continues to focus on its simplification, another group of developers are reviving the original version of RDF (0.90) Because RSS claims to be more flexible. They finally released an RSS 1.0 version named "RDF Site Summary ". Because of the use of RDF, this version is completely different from the version controlled by userland software. Of course, userland software is reluctant to see the fact that RSS 1.0 seems to replace its version 0.94, so a new version is released and the version is jumped to 2.0.
This is today's situation, forming two major competing versions: one based on RDF 1.0, and the other based on not (2.0), but both of them share the same name. This is a terrible mess, because the version numbers lead to people mistakenly think that 2.0 is an improved version of 1.0, but they are actually two completely different standards. Another group of developers has begun to solve this confusion by defining a new syndication specification to break away with the random RSS name. This solution is called an atom project. This article will be discussed in detail later.
Which version is actually irrelevant? Most RSS aggregation mechanisms support all RSS versions (some even support atom ). The final decision depends on whether you want to use RDF. It can be called radish cabbage and love each other. It depends entirely on the concept of semantic web that someone believes in.

What does RSS 1.0 and RSS 2.0 look like?

The core information contained in the RSS 1.0 and 2.0 formats is the same, but its structure is different. I provide an RSS 1.0 document (see figure 1) and an equivalent RSS 2.0 (see figure 2) for comparison.
You will notice the difference between the root elements at the right of the top line. The root element of RSS 1.0 is RDF: RDF, and the root element of RSS 2.0 is RSS. RSS also contains a forced version attribute to indicate the exact format of the RSS used (possible values include 0.91, 0.94, and so on ). Another major difference is that there is a namespace limit for RSS 1.0 documents, so there is no RSS 2.0 document. In any case, the information contained in the two documents is essentially the same.
Both versions contain the channel element, and the channel element contains three required elements: title, description, and link. The Code is as follows:

<Channel>
<Title> <! -- Channel title --> </title>
<Description> <! -- Brief description --> </description>
<Link> <! -- Channel URL --> </link>
<! -- Optional/extensible element -->
</Channel>
In addition to these required elements, RSS 1.0 defines three additional elements: image, items, and textinput. Image and textinput are optional. On the other hand, RSS 2.0 provides 16 additional elements, including image, items, and textinput, as well as language, copyright, managingeditor, pubdate, and category. RSS 1.0 allows you to create this type of metadata by defining extensible elements in a separate XML namespace.
The main difference between the two formats must be the representation of their item, image, and textinput nodes. In RSS 1.0, the channel element contains references to the item, image, and textinput nodes, which exist outside the channel Node itself. In this way, an RDF association is established between the channel and the referenced node. As shown in figure 1, the channel element is associated with an image element and two item elements. In RSS 2.0, the item element is discharged continuously in the channel element (as shown in Figure 2 ). The item element contains the actual news item information. The item structure is the same in two versions. The item element usually contains the title, link, and description elements, as shown in the following code:

<Item>
<Title> <! -- Item title --> </title>
<Link> <! -- Item URL --> </link>
<Description> <! -- Brief description --> </description>
<! -- Optional/extensible elements -->
</Item>
In RSS 1.0, title and link are required, and description is optional. In RSS 2.0, either the title or description must be provided. Other options are available. These are just the item elements defined in RSS 1.0. RSS 2.0 provides several other optional elements, including author, category, comments, enclosure, guid, pubdate, and source. RSS 1.0 obtains such metadata by defining an extensible element called the RSS module in a separate XML namespace. For example, in figure 1, the date of an item is represented by the <DC: Date> element of the dublic core module.

For complete information about different formats, see the RSS 1.0 and 2.0 specifications.

So what is Atom?

As mentioned above, atom is the name of a project. It is mainly used to develop a new log digest format to solve the current RSS problem (the chaotic version number is not a real open standard, indicating inconsistent methods, poor definitions, and so on ). Atom wants to provide a clear version to meet everyone's needs. Its design is completely independent of suppliers, and anyone can freely scale it out. A complete description is provided.
Today, many blog engines support the current digest format. Figure 3 is an example of an atom 0.3 feed, which is equivalent to the preceding figure 1 and figure 2 RSS feeds. Note that atom feeds are limited by namespaces, but do not use RDF. This makes atom and RSS 1.0 and RSS 2.0 similar in some places. Whether atom will be accepted in the future remains to be seen.
In addition to defining the new digest format, Atom also wants to define a standard archive file format and a standard website editing API (atom API ). For details about atom specifications and other atom resources, visit the Atom project.

What is blogroll?

Blogroll is a collection of blog feeds. Most blogger (blogs) provide blogroll on their personal blogs. This allows the reader to connect to the blogs of other people with different interests and writing styles. Blogroll facilitates network communication. By using outline processor Markup Language (opml), people can exchange blogroll files in XML format. Figure 4 is an example of blogroll.
Most log engines manage blogroll by themselves, and each time the reader requests blogroll, the corresponding XML format is generated by themselves. Similarly, most aggregators can import blogroll and automatically schedule the summary contained. For more information about opml, see http://opml.scripting.com.

Can you explain what referrers, trackbacks, and pingbacks are?

Most logtail software allows readers to add blog comments. However, a more common practice is to allow the reader to add an ingress relink to the original post on his or her own blog. Bloggers are happy to track the time when a connection occurs so that new readers can understand the entire session.
A referrer is an external site. You can click a hyperlink on the site to access your website. Many indexing engines automatically keep track of your indexing portal. Most engines display a referrers list at the bottom of the blog entry so that readers can navigate back to the referrer site and understand what they want to say about the entry. This is based on the assumption that, that is, if they link to it, they may write something about it. The problem with referrer is that this assumption must be established-there is not enough information to indicate whether the referenced page actually contains the relevant information. In fact, spam publishers have used this vulnerability to redirect readers for marketing purposes.
Trackback and pingback have the same specification and are used to remedy the above problems. With trackback and pingback, other blogs can automatically send a ping to your blog to explicitly indicate that they have written an entry to reference a specific post.
This type of Anti-chain allows your blog to display a list of all comments in a more obvious way. Most wangzhi software today supports all of these technologies. See trackback technical specification and pingback 1.0.

How can I generate an RSS feed for my site?

Figure 5 illustrates how to use the ASP: Repeater control to generate an RSS 2.0 feed on the. ASPX page. This page assumes that you have set the datasource attribute of the control to the corresponding database result set in the back-end code file.

I want to aggregate several RSS feeds and display the information on my website. Can I explain how to implement this?

Because RSS feeds are XML files, you can use XML APIs that you are best at, such as Microsoft.. NET Framework. XML, figure 6 contains ASP. net web user control code, which is written by me to aggregate the blogroll file (. opml. This Code assumes that the opml element contains the numbertodisplay attribute to indicate the number of items in each feed you want to display.

Figure 7 ASP. NET web user control

You can drag controls to any. on the ASPX page, it displays the items of different feeds listed in the blogroll file, and Figure 7 shows Utah. net user group website uses the effect screen of this control.

Is there any Web Services APIs that interacts with wangzhi?

Many wangzhi engines provide their own web service interfaces and interact with wangzhi through programming. However, there is no standardization at present.
Both. Text and dasblog provide some. asmx endpoints, which can be edited through soap, but their interfaces are different. Blogger.com provides XML-RPC-based interactive APIs ). Userland software has enhanced the function of Blogger API and called it metaweblog API. These may be recognized as the Internet log APIs, but they are still not supported by all the Internet log engines. Another dedicated API for adding comments is called comment API, which is not widely supported.
The atom group is working to solve these problems. The Atom API defines a standard blog API for publishing and editing the Blog content. For more information, see the Atom project website.

Send questions and comments to Aaron: xmlfiles at Microsoft dot com.
　
Author Profile
Aaron skonnard teaches at northface University in Salt Lake City. We work with people on "essential XML Quick Reference" (Addison-Wesley, 2001) and "essential XML" (Addison-Wesley, 2000). We often give speeches at meetings. You can contact him in http://www.skonnard.com.
This article is from msdn magazine's 2004 Journal, which can be obtained through a local newsstand or preferably subscribed.