Drupal 7 Module Development

Chapter 4
In Chapter 5, Building an Admin Interface, you'll learn how to build administration
forms that could make our single_blog module configurable, but in this chapter we
simply created a few PHP constants that define the node type to use for blog entries
and the list count for block.
Next up, we provided a simple API for our module that allows any code to retrieve
a list of blog nodes; we've called the function single_blog_list(). We're using
Drupal's Database API to query for the data. You can learn more about it from
Drupal's online documentation at http://drupal.org/node/310069. For now,
you'll have to rely on DB API's relatively self-documenting method names. We
selected the unique node ID, title, creation date and author (uid stands for user ID)
fields of nodes that are of the SINGLE_BLOG_NODE_TYPE content type and that are
published (status = 1). We only selected the $number latest nodes that have
been created.
Why did we create a single_blog_list() function instead of just putting that
database query code inside hook_block_view()? Some Drupal developers get so
caught up in hooking into Drupal's APIs that they forget to write abstracted APIs for
their own module's business logic. Don't make that same mistake. We could put the
database query inside a Drupal hook, but that reduces the chance that other modules
can integrate with your module in ways you could never anticipate. Remember, be
lazy. If your module's API is good enough, some other developer will write the code
to integrate your module with theirs.
Now that we have our API function written, let's use it to build the block using
Drupal's Block API:
/**
* Implements hook_block_info().
*/
function single_blog_block_info() {
$blocks = array();
// The array key defines the $delta parameter used in all
// other block hooks.
$blocks['recent'] = array(
// The name of the block on the blocks administration page.
'info' => t('Recent blog posts'),
);
}
return $blocks;
/**
* Implements hook_block_view().
*
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