An Introduction to WCTL - A Non-Programmer's Guide to Web Crossing

In the previous section, you created a simple script and placed it in a folder header. The script contained the expression %% user.userName %%. When the folder header was displayed, %% user.userName %% was automatically replaced by the logged in user's user name. This expression, including the surrounding double-percent marks, was written in the Web Crossing Template Language (WCTL).

WCTL is Web Crossing's traditional scripting language. Almost all you see in Web Crossing - folders, discussions, messages, the login form, the registration form, the form in which you set user preferences, etc., are defined as templates which are written as a combination of standard HTML mixed with WCTL. You can modify these templates to gain almost 100% control over your Web Crossing conference.

WCTL is a full programming language, with variables and conditional structures, file I/O, filters, email abilities and many other features. Using WCTL you can modify not only the appearance of your Web Crossing forums, but also the actions taken when users access your forums. You can even use WCTL instead of ordinary CGI (Common Gateway Interface) programs to do things like provide hit counters for your Web Crossing pages and form handling, such as form to email handlers. These are easily accomplished using WCTL.

Before we start in on writing full templates, let's look some more at the expression %% user.userName %% and understand all the parts of this expression. Understanding the syntax of WCTL will help reduce your learning curve and get you started with your own customization more quickly.

The contents of a WCTL expression are evaluated and mixed in with the rest of your HTML to create a web page which is sent to the user's browser.

became substituted by the current (accessing) user's user name. If the user's name was Doug, then

Note: Spaces in WCTL expressions (between the percent marks) are ignored. For example, %% user.userName %% and %%user.userName%% are evaluated the same way. Extra spaces are not added to the HTML created by Web Crossing. You can include spaces in your expressions to make your WCTL easier to read.

In between the percent-marks the WCTL expression user.userName is a variable (a place holder for values) with two parts

The word user (before the period) is the type of variable and the word userName (which follows the period) is the name of the variable (or, as we often call it, the property). The userName property is a standard Web Crossing property belonging to all Web Crossing registered users. Each user has a unique userName that is set at registration time.

There are various standard user properties such as userEmail (the email address set when a user is registered) and user2ndLine (the 2nd profile line user's can set when editing their preferences).

Using WCTL you can also create your own customized user properties (such as telephone number, sex, age, address, etc.) and add these properties to the Web Crossing database. Customized user properties are stored in the Web Crossing database and can be used just like other properties; you can use them in WCTL expressions and use them for searches, etc. We will see how to add customized user properties later on.

The user type refers to "the registered user currently accessing Web Crossing." In other words, if a user opens a Web Crossing forum and WCTL in the page contains %% user.userName %%, the accessing user sees his or her own name.

Another type of variable - the author type - refers to the author (the person who created a message or any other person being referred to besides yourself) of the location being looked at. For example, when you see a Web Crossing message written by somebody, the underlying WCTL to display the author of that message is not %% user.userName %% it is %% author.userName %%.

Perhaps the most common mistake that WCTL beginners make is confusing user and author variable types. Just remember - a user variable refers to the actual user who is accessing and looking at the conference. An author variable refers to the other users - people who wrote messages, for example. We will be returning to this important point again and again.

To clarify the difference between user and author variables, try this simple test.

After you have saved the changes to the header, go back and open the folder. You will see that the first line shows the name of the author of the folder - the test user you created. The second line shows your name. Think back on this example if you ever get confused by the difference between user and author variables.

In addition to user and author variables, WCTL also has other variable types. We will be referring to these types as needed in subsequent sections. The following table summarizes the various variable types:

Variable type	Meaning
untyped (example: myMessage)	If no type is specified, the variable is considered a local variable. This variable is useful in macros as temporary place holders for values. Local variables exist only during the current execution of a macro and are not stored in the Web Crossing database.
user (example: user.userName)	A user variable refers to the currently accessing user. You can add new user properties whenever you want and the values will get saved in the database.
author (example: author.userName)	An author variable refers to the author of the current location or any third person whose properties you are changing (for example, if you change a user's preferences via the Control Panel). These values are also saved in the database.
path (example: path.title)	A path variable refers to the current location (top level, folder, discussion, message, chat room or link). You can add new path variables whenever you want and these values are also saved in the database.
site (example: site.totalVisitors)	A site variable is a global variable that can be referenced from anywhere. It is stored in the database and can be used at any time. You can add as many site variables as you want.
session (example: session.count)	A session variable is a temporary variable that lasts only during a user's access session. Each session variable is assigned to the currently accessing user and is tracked by following the user's certificate. The user does not have to be a registered user. Session variable are not saved in the database. You can use session variables to track a visitors page views, keep track of a user's shopping cart, etc.

The next section will use some of these variable types and show you more about WCTL syntax and usage.

I tried the example above, but when I look at the header all I see is the WCTL itself, with all the double-percent marks. What am I doing wrong?

WCTL Server-side Scripting