The Controversial CDATA programming construct has caused somewhat of a love-hate relationship among RSS programmers. What is CDATA? Well to put it in very easy terms, it allows us to place within the description sub-element of Item, HTML commands and language. In other words it extends the description by allowing us to create links, references and the like within what is purely a text element created to describe the item.
Remember that within the Item element, the sub-element of description will look like this.
Let us say I want to extend this piece and I wanted to get a Bold command
Remember Randy Pandy and his Perfumery at randypandy.com? Well now not only does his wife Sandy want to describe the HeavenScent Skunk Perfume but she wants a picture of the bottle with the description. So, hold on, you say. Easy as pie. Use the enclosure command. Well right and not right. Sure you can put a picture of the perfume bottle in the enclosure command, but it will NOT appear WITH the description. It will appear alone and then the user will have to read the description. So while this is GREAT for audio and video a plain visual that I want next to a description kind of gets left alone if I just put in an enclosure.
So we have the description, and for the sake of all I will repeat it here.
Created especially by Skunk Perfumes it is their newest and best
selling perfume on the market today. Purchase a beautifully shaped
skunk bottle with this incredible perfume and get a whopping 50%
off! And if you purchase over $100 we will throw in Free overnight
delivery as well!
Okay now Sandy wants a picture to go right into that description and when the user sees the text in their aggregator they will also get a visual. Thus the CDATA command.
First lets look at it in action and then we will explain.
Heaven Scent Perfume the Smell your lover will die for. Created randypandy.com -
especially by Skunk Perfumes it is their newest and best selling
perfume on the market today. Purchase a beautifully shaped skunk
bottle with this incredible perfume and get a whopping 50% off!
And if you purchase over $100 we will throw in Free overnight
delivery as well!
All Perfumes You Can Ever desire
Heaven Scent Perfume the Smell your lover will die for. Created
Notice first what we did? First we set the tag description. Then within it immediately we tell the file “Hey get ready for some good old HTML”, and thus we add the
Next we want our picture of the perfume. So for those of you who know HTML this is simple. We give it the image information.
After that we continue with our description. Get in a few line
breaks with either the
finally before the end we close it off with ]] tag.
You can get fairly sophisticated with CDATA. The thing is many programmers do NOT like it, as it allows too many rooms for mistakes, and it is a throwback to old HTML. The purity of the XML is kind of compromised here. But it serves a purpose and allows us to get a picture with the words, which is incredibly important. Many, many RSS feeds use it, and it is a very useful tool to get the “picture” across to the user. You can combine it as well with enclosure, to get an audio out, a description, and say a picture of the Album. In other words a full media experience of text + picture + audio.
Well that is it. Our next article will put it all together and give you a look at the final well formed XML file which will act as our template for rss.xml. It will lay it all out for you with a couple of items, so you can grab it and use it for your RSS feed.
This Article was Part Nine of the series – RSS Mania Understanding RSS. All of this series is available at Ezine Articles (ezinearticles.com)
Copyright © 2005 Ted W. Gross. All rights reserved. (You may publish this article in its entirety with the following author’s information with live links only.)
Ted W. Gross owns Virgin Earth http://www.virginisrael.com, a real estate brokerage firm in Jerusalem, Israel. Virgin Earth represents residential and commercial real estate all over Israel. Virgin Earth also maintains an RSS Feed on its current properties and also operates Virgin Earth – Israel Tourism & Information Portal on the same site. Ted Gross is also a published author and maintains a web site for his works. This can be found at: http://www.virginisrael.com/twg/iw.html. Virgin Earth Blog can be found at: http://virginearth.blogspot.com/