Drupal 7 Module Development

Theming a Module
Now that you've learned the architecture of the theme layer, let's put that knowledge
to practical use. In this chapter, we'll write some real code that both uses existing
theme implementations and builds new theme implementations.
While the previous chapter was a whirlwind tour of the theme layer, this chapter
will be a more thoughtful exploration of the system and how to best use it. We'll
touch on the following ideas:
• The advantages of being lazy by reusing code
• Finding and reusing a theme hook
• Attaching CSS to render elements
• Creating stylesheets for RTL languages
• Building a theme hook
To help us learn these points, we're going to build a simple module in our examples.
Drupal comes with the blog module, which creates multi-user blogs, one for each
user and one aggregate blog. However, many websites only need a single blog. We're
going to re-create some of the functionality of the blog module, and re-purpose it
for a single blog that uses Drupal's default article content type. If you try out this
chapter's code, you should disable Drupal 7's blog module first.
Reusing a default theme implementation
Now the first question you need to ask is "Should I reuse an existing theme hook or
build my own?" Code reuse is one of the virtues of a lazy programmer. So the answer
to that question is "Yes, be lazy!"