block_example.module
<?php
// $Id: block_example.module,v 1.9 2007/07/06 18:16:15 drewish Exp $
/**
* @file
* This is an example outlining how a module can define blocks to be
* displayed on each page.
*/
/**
* Implementation of hook_block().
*
* This hook both declares to Drupal what blocks are provided by the module, and
* generates the contents of the blocks themselves.
*/
function block_example_block($op = 'list', $delta = 0, $edit = array()) {
// The $op parameter determines what piece of information is being requested.
switch ($op) {
case 'list':
// If $op is "list", we just need to return a list of block descriptions.
// This is used to provide a list of possible blocks to the administrator,
// end users will not see these descriptions.
$blocks[0] = array(
'info' => t('Example: configurable text string'),
);
// A block can provide default settings. In this case we'll enable the
// block and make it visible only on the 'node/*' pages.
$blocks[1] = array(
'info' => t('Example: empty block'),
'status' => TRUE,
'weight' => 0,
'visibility' => 1,
'pages' => 'node/*',
);
return $blocks;
case 'configure':
// If $op is "configure", we need to provide the administrator with a
// configuration form. The $delta parameter tells us which block is being
// configured. In this example, we'll allow the administrator to customize
// the text of the first block.
$form = array();
if ($delta == 0) {
// All we need to provide is a text field, Drupal will take care of
// the other block configuration options and the save button.
$form['block_example_string'] = array(
'#type' => 'textfield',
'#title' => t('Block contents'),
'#size' => 60,
'#description' => t('This string will appear in the example block.'),
'#default_value' => variable_get('block_example_string', t('Some example content.')),
);
}
return $form;
case 'save':
// If $op is "save", we need to save settings from the configuration form.
// Since the first block is the only one that allows configuration, we
// need to check $delta to make sure we only save it.
if ($delta == 0) {
// Have Drupal save the string to the database.
variable_set('block_example_string', $edit['block_example_string']);
}
return;
case 'view': default:
// If $op is "view", then we need to generate the block for display
// purposes. The $delta parameter tells us which block is being requested.
switch ($delta) {
case 0:
// The subject is displayed at the top of the block. Note that it
// should be passed through t() for translation.
$block['subject'] = t('Title of block #1');
// The content of the block is typically generated by calling a custom
// function.
$block['content'] = block_example_contents(1);
break;
case 1:
$block['subject'] = t('Title of block #2');
$block['content'] = block_example_contents(2);
break;
}
return $block;
}
}
/**
* A block content function.
*/
function block_example_contents($which_block) {
switch ($which_block) {
case 1:
// Modules would typically perform some database queries to fetch the
// content for their blocks. Here, we'll just use the variable set in the
// block configuration or, if none has set, a default value.
return variable_get('block_example_string', t('A default value.'));
case 2:
// It is possible that your block will not have any content, since it is
// probably dynamically constructed. In this case, Drupal will not display
// the block at all.
return;
}
}