block_example.module

<?php


/**
 * @file
 * This is an example outlining how a module can define blocks to be
 * displayed on each page.
 */

/**
 * @defgroup block_example Example: Block
 * @ingroup examples
 * @{
 * Block defined by a module. (drupal 6)
 *
 * This example is part of the Examples for Developers Project which you can download
 * and experiment with here: http://drupal.org/project/examples
 */

/**
 * 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 = '', $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['configurable-text'] = 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['empty'] = 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 == 'configurable-text') {
                // 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 == 'configurable-text') {
                // Have Drupal save the string to the database.
                variable_set('block_example_string', $edit['block_example_string']);
            }
            return;
        case 'view':
            // 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 'configurable-text':
                    // 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 configurable-text block');
                    // The content of the block is typically generated by calling a custom
                    // function.
                    $block['content'] = block_example_contents(1);
                    break;
                case 'empty':
                    $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;
    }
}

/**
 * @} End of "defgroup block_example".
 */