Monday 23^rd April

Xml- More on Markup Languages
This afternoon some of us will be getting our first taste of a mark-up language other than XHTML! It’s called Scalable Vector Graphics (SVG) – and the great thing is, you’ll find because you’ve been learning XHTML and Stylesheets, you’ll be able to pick up SVG really easily! In fact, there’s lots of different Markup languages – one for every purpose you could think of!
What is xml?
XML (Extensible Markup Language) is a standard for creating markup languages which describe the structure of data. It is not a fixed set of elements like HTML, but rather, it is like SGML (Standard Generalized Markup Language) in that it is a metalanguage, or a language for describing languages. XML enables authors to define their own tags. XML is a formal specification of the World Wide Web Consortium. To find XML editors, see `Whirlwind Guide to SGML to ols’ http://www.infotek.no/sgmltool/editetc.htm and also http://www.stud.ifi.uio.no/~larsga/linker/XMLtools.html.

Useful site for other markup languages:
http://www.acad.bg/beginner/gnrt/appendix/glossary.html

Information for xml challenges.
How to make yellow?
Eg. Stroke: rbg (255,255,0); Red, green, blue- To make yellow add full strength red and full strength blue.
Additive colors are easy to demonstrate on a color computer monitor equipped with a color-control program. Just so happens I have one right here. How do we make yellow? By adding full-strength red and full-strength green. Adding two-thirds strength blue gives us a lighter (not darker) yellow. Full-strength blue, red, and green produce bright white. This is a counterintuitive result if you learned your color-mixing skills in kindergarten. But we know that white light can be broken into all the colors of the rainbow. So we shouldn’t be surprised to learn the process also works in reverse–i.e, the colors of the rainbow can be combined to make white. Besides, it only stands to reason that the more light you shed on something, the brighter (that is, closer to white) it gets.
From: http://www.straightdope.com/classics/a3_344.html

What is Opacity? Opacity is the amount of light which is blocked by a medium, like smoke or a tinted window. Opacity is a measurement and is usually stated as a percentage. An opacity of 0% means that all light passes through, and an opacity of 100% means that no light can pass through. Opacity is important because it gives an indication of the concentration of pollutants leaving a smokestack. The more particles which are passed through a stack, the more light will be blocked, and, as a result, a higher opacity percentage is achieved. From http://www.geocities.com/gawhitlow/whatisopacity.htm

Opacity in challenge one, is the control of white coming through the fill in the rectangle.

XML Challenge 4- Roll your own RSS feed.
RSS Definitions-
RSS is a family of web feed formats, specified in XML and used for web syndication.[1]( [1] Web syndication is a form of syndication in which a section of a website is made available for other sites to use. This could be simply by licensing the content so that other people can use it; however, in general, web syndication refers to making Web feeds available from a site in order to provide other people with a summary of the website’s recently added content (for example, the latest news or forum posts).
RSS is a family of web feed formats used to publish frequently updated data, such as blogs, news feeds and podcasts.

Users of RSS content use software programs called “feed readers” or “feed aggregators”. The user subscribes to a feed by entering a link to the feed into the reader program. The reader can then check the user’s subscribed feeds to see if any of those feeds have new content since the last time it checked, and if so, retrieve that content and present it to the user.

Helpful page on RSS- http://www.xul.fr/en-xml-rss.html.

Interesting site Andrew sent me involving grid design of sites- http://tutorialblog.org/grid-systems-in-web-design/