1.4 DATA FORMATS
• The format of the data is important so that other programs may interpret it correctly.
1.4.1 HTML - Hyper Text Markup Language
• This is a format that is invisible to the user on the web. It allows documents to be formatted to fit the local screen.
• Editors are available that allow users to update HTML documents the same way they use word processors.
18.104.22.168 - Publishing Web Pages
• Once a web page has been modified it is necessary to put it back on the web server.
• When publishing a page with a browser ‘FTP’ will be used.
• The web page called ‘index.html’ is the first one to be returned. If you are publishing a main page your main page should be called ‘index.html’.
• Keep in mind that the website is just another computer. You have directories and files there too. To create a web site that has multiple files we need to create other files or directory names.
• Note that some web servers do not observe upper/lower case and cut the ‘html’ extension to ‘htm’. Microsoft based computers are notorious for this, and this will be the most common source of trouble.
• In HTML documents we need to refer to resources. To do this we use a label to identify the type of resource, followed by a location.
• Universal Resource Locators (URLs)
• Below is a list of hints for publishing web pages
- Windows will not allow multiple applications to open the same file at the same time. If you seem to be having trouble opening a file, make sure it is not open in another application.
- As you add other files to your homepage, put them in the ‘temp’ directory. This will make all of the procedures simpler.
- Try to make your web pages small, and link them together. This will decrease download time and make browsers happier.
- Avoid using excessive images. Anything over 10K will make it very slow downloading over modem. Anything over 100K makes modem downloading painfully slow.
- When putting images on the web page use ‘jpg’ for photographic images, and ‘gif’ for line images. ‘jpg’ images can be compressed more than ‘gif’, but lines will become blurred.
- To link to other files or web pages there will be a ‘link’ command. If you want to add a file that is in your ‘temp’ directory, just put the name of the file in the ‘URL’ field.
- Watch upper/lower case. This is a major cause of web page problems.
1.4.4 Specialized Editors
• There are a variety of editors that will allow us to edit single web pages or entire sites.
• These programs include,
- Microsoft Word
• A format proposed by Adobe. This is not a ‘standard’, but is very widely accepted.
• When documents are presented in pdf format their original layout is preserved (HTML will actually change the look/layout of a document), but the files become hard/impossible to work with.
• A special plug-in is required to view these files.
• Allows some degree of privacy, but this is not guaranteed.
• Basically, if you have something you don’t want seen, don’t do it on the computer.
• We can make a file smaller by compressing it (unless it is already compressed, then it gets larger)
• File compression can make files harder to use in Web documents, but the smaller size makes them faster to download. A good rule of thumb is that when the file is MB is size, compression will have a large impact.
• Many file formats have compression built in, including,
images - JPG, GIF
video - MPEG, AVI
programs - installation programs are normally compressed
• Typical compression formats include,
zip - zip, medium range compression
gz - g-zip - good compression
Z - unix compression
Stuffit - A Mac compression format
• Some files, such as text, will become 1/10 of their original size.