Velocity model and data objects in Apache Roller
There are several standard model and data objects you can use in Apache Roller to access your weblog’s data. Some of the most widely used are $config, $model, $url, $utils, $weblog, $weblogCategory, and $weblogPage. In the following exercise, you’ll get to work with the $config object.
The $config object
This model is used to access Roller’s site-wide configuration parameters, such as the e-mail address of Roller’s administrator, the name of the Roller site, and so on.
Time for action – properties of the $config model object
The following exercise will show you how to use some properties of the $config model object inside your custom template:
- Go to your custom template editing page, and replace the six lines of code below the <body><html> line with the following lines:
Welcome to my blog, <b>$model.weblog.name</b> --> <i>$config.
siteDescription</i> </br>
I'm using Apache Roller Version <b>$config.rollerVersion</b> </br>
You can e-mail me at <b>$config.siteEmail</b> if you run into any
problems in this site. </br>
This is my first template </br>
My weblog's absolute URL is: <b>$url.absoluteSite</b> </br>
</br> - The entire code of your template should look like the following screenshot (the code you have to change is highlighted):
- Save your changes and click on your template’s [launch] link to open a new tab in your web browser and see the results:
- Close the results tab if you like, but leave the Frontpage: Templates window open for the next exercise.
What just happened?
The following table summarizes the $config object properties you learned to use in the previous exercise, along with their value:
Property |
Definition |
Value |
$config.siteDescription |
Shows your site’s description. |
My First Installation of Apache Roller |
$config.rollerVersion |
Shows the Apache Roller version used. |
4.0.1 |
$config.siteEmail |
Shows the site administrator’s email. |
You can find all $config parameters under Roller’s Server Admin tab:
The $model, $category, and $entry objects
These objects are used to access all the data for a specific weblog: weblog entries, categories, comments, among others.