Weblogs, CMS, and Web Servers

Today we'll be talking about weblogs. What are they? How are they different from "regular" web sites? What opportunities and challenges do they present for web developers? Weblogs are a specialized type of CMS, or content management system, so we'll talk about CMS more generally, as well.

Weblogs will be an integral part of the course this quarter. This site, for example is a special-purpose weblog. Each of you will be creating your own weblogs for posting in-class exercises and links to assignments, as well as your thoughts on lectures and readings.

Because the Movable Type weblog software we'll be using is a set of programs that run on the web server, we'll review some basic server concepts so that you can install the programs in your Grace account.

Readings on Weblogs and CMS

• Wikipedia entries on blogs, wikis, and content management systems.
• Chapter 2: The Read-Write Web (PDF) from Dan Gillmor's book We, the Media
• Blogs open doors for developers (ZDNet)
• Why Content Management Fails

Installing Movable Type: In-Class Exercise

1) Telnet (or secure shell) to grace, and use pwd to find the full path to your home directory (you'll need this later, so write it down). Mine is /users/rit0/g1/ellics, but yours will be slightly different.

2) If one doesn't already exist, create an .suexec file in www directory. (The presence of this file allows the web server to run CGI programs as "you," so that you don't have to give write permissions to the whole world.) The easiest way to create the file is to use the "touch" command.

3) You're going to need three directories--one in your home directory to hold the database files, one in your www directory for the movable type program files, and another one in your www directory for the publicly-viewable blog files. In the examples below, the database directory is called db, the movable type program directory is called mt, and the blog directory is called blog. You can call these whatever you want. The permissions on all three directories must be set to 755.

(If you use the example directory names, the path to log into your blog for editing and configuration would be http://www.rit.edu/~yourid/mt/ , and the path to read your blog would be http://www.rit.edu/~yourid/blog/)

When done, log out from grace.

4) Go to the Movable Type site and click on the "free download" button. Download the full version of the software in .zip format.

5) Upload the .zip file to your www directory on grace, and decompress it using the unzip command. Rename the resulting directory as mt, and change the permissions for the directory and all of its contents to 755 (chmod -R 755 mt)

6) Edit the mt.cfg file using pico or vi. (More detailed information on the configuration file can be found in the Movable Type installation documentation, on their web site. This is an abbreviated version of the instructions specifically for the RIT web server.)

• change the CGIPath variable to be http://www.rit.edu/~yourid/mt/ (if you chose a different name for the movable type file directory, use it here)
• change the DataSource line to show the full directory path to your db directory (e.g. /users/rit0/g1/yourid/db), substituting your path from step 1, and the name you gave your db directory
• Uncomment the following lines in the file by removing the # from in front of them.

DBUmask 0022
HTMLUmask 0022
UploadUmask 0022
DirUmask 0022

7) Open a browser and run the mt-check program to test the installation: http://www.rit.edu/~yourid/mt/mt-check.cgi

If mt-check.cgi is successful, run the mt-load program to initialize the software http://www.rit.edu/~yourid/mt/mt-load.cgi

(Substitute the name of your movable type directory if you didn't use mt)

If mt-load runs properly, delete the file so it can't be re-run.

8) Use a browser to go to http://www.rit.edu/~yourid/mt/mt.cgi and log in with the default values--user Melody, password Nelson. Immediately edit your profile to change the user name and password to what you want. (The user name will be what shows up on your posts, so choose something you'd like to be "public".)

9) Choose "Manage Weblog" for the default weblog that was created, and then select "Weblog Config" from the menu on the left.

10) On the first config screen, you need to enter the UNIX path to your blog directory, and the URL to the directory; then add "archives" to the end of each for the next two fields. It should look much like the example below, but with your user ID and path substituted for mine.

11) Now choose "Rebuild Site" from the menu at the left, and click Rebuild to save all the html files your weblog to the specified directory. Test it by clicking on the "View Site" button at the top of the screen.

Web Developer's Toolbar

A colleague has pointed me to the very useful Web Developer's Extension, an extension for both Firefox and Mozilla.

It has an extraordinary number of useful features, which I'll be talking about in class today. I encourage you to install this extension on your own computers, and I've asked our sysadmins to install it on the IT computers as well.

Wikipedia

For today's class I asked you to read several articles from the Wikipedia. What you may not have realized is that every page on the Wikipedia site can be edited by any user--including you. How does that change your assessment of the site as a resource? Do you trust it more? Less?

(This has been a lively topic recently in the "blogosphere," with several people running empirical tests of how quickly the site is "self-healing" when errors are introduced.)