drupal module 开发的例子

需求:
开发一个module，列出某一时间段内的所有node。module的名称为current_posts

开始
1 module的文件放的位置
在drupal中，$DRUPAL_ROOT/sites/all/modules 存放非core的module。我们在此目录下建立名为current_posts的目录, 所有的current_posts module的文件都放在此目录下。

2 module的描述文件current_posts.info
current_posts.info文件描述了module的基本信息。current_posts.info的内容为：
name = Current posts
description = A block module that lists links to rencent posts.
core = 7.x
files[] = current_posts.test

.info文件的格式
必填的字段:
name
description
core
可选的字段:
files
例：file[] = example.test
Drupal 支持动态加载代码。module要在files字段中包含定义class和interface的文件。在enable module的时候，Drupal会扫描files字段指定的文件，记录所有的class和interface。当访问class和interface, 他们会被自动php加载
dependencies
例：dependencies[] = taxonomy   
例：dependencies[] = comment
本module需要qitamodule的支持，如果依赖的module没有enable，则本enable本module会失败
package
例：package = "you arbitrary grouping string"
module的分组。如果没有package字段，module默认被分到others

3 实现hook
一般的把hook的实现函数写到module_name.module文件中，对于本例，对应的写到current_posts.module
3.1 实现hook_help
function current_posts_help($path, $arg){ switch ($path) { case "admin/help#current_posts": return '<p>'. t("Displays links to nodes created on this date") .'</p>'; break;} 
当访问admin/help/current_posts时，会看到help的内容
3.2 实现hook_block_info
function current_posts_block_info(){ $blocks['current_posts'] = array( 'info' => t('Current posts'), //block的信息，会出现在block列表里 'cache' => DRUPAL_CACHE_PER_ROLE, //Default ); return $blocks;} 
3.3 获取数据
function current_posts_contents($display='block'){ $today = getdate(); $start_time = mktime(0, 0, 0,$today['mon'],($today['mday'] - 7), $today['year']); $end_time = time(); $query = db_select('node', 'n') ->fields('n', array('nid', 'title', 'created')) ->condition('status', 1) //Published. ->condition('created', array($start_time, $end_time), 'BETWEEN') ->orderBy('created', 'DESC'); //Most recent first. /*if('block' == $display) { //如果没有取到current_posts_max，则最多显示3条 $max_num = variable_get('current_posts_max', 3); $query->range(0, $max_num); } */ return $query->execute; } 
3.4 实现hook_block_view
function current_posts_block_view($delta = ''){ switch($delta){ case 'current_posts': $block['subject'] = t('Current posts'); if(user_access('access content')){ $result = current_posts_contents('block'); $items = array(); foreach ($result as $node){ $items[] = array( 'data' => l($node->title, 'node/' . $node->nid), ); } if (empty($items)) { //No content in the last week. $block['content'] = t('No posts available.'); } else { //Pass data through theme function. $block['content']['posts'] = array( '#theme' => 'item_list__current_posts__block', '#items' => $items, ); //Add a link to the page for more entries. $block['content']['more'] = array( '#theme' => 'more_link__current_posts', '#url' => 'current_posts', '#title' => t('See the full list of current posts.'), ); } } } return $block;} 
3.5 配置module
3.5.1 准备配置module的表单
实现hook_menu
function current_posts_menu(){ $items = array(); $items['admin/config/content/current_posts'] = array( 'title' => 'Current posts', 'description' => 'Configuration for Current posts module', 'page callback' => 'drupal_get_form', 'page arguments' => array('current_posts_form'), 'access arguments' => array('access administration pages'), 'type' => MENU_NORMAL_ITEM, ); $items['current_posts'] = array( 'title' => 'Current posts', 'page callback' => '_current_posts_page', 'access arguments' => array('access current_posts content'), 'type' => MENU_CALLBACK, //Will not appear in any menu. ); return $items;} 
当访问admin/config/content/current_posts时会调用page callback指定的函数，并给函数传递page arguments指定的参数
type的值为MENU_NORMAL_ITEM时， 会在navigation菜单中
function current_posts_form($form, &$form_state){ $form['current_posts_max'] = array( '#type' => 'textfield', '#title' => t('Maximum number of posts'), '#default_value' => variable_get('current_posts_max', 3), '#size' => 2, '#maxlength' => 2, '#description' => t('The maximum number of links to display in the block.'), '#required' => TRUE, ); return system_settings_form($form);} 

3.5.2 校验数据 实现hook_form_validate
function current_posts_form_validate($form, &$form_state){ $max_num = $form_state['values']['current_posts_max']; if (!is_numeric($max_num)){ form_set_error('current_posts_max', t('You must enter an integer for the maximum number of posts to display.')); } else if ($max_num <= 0){ form_set_error('current_posts_max', t('Maximum number of posts to display must be positive.')); }} 
3.5.3 权限设置 实现hook_permission
function current_posts_permission()
{
    return array(
        'access current_posts content' => array(
            'title' => t('Access content for the Current posts module'),
            )
        );
}
3.6 适配查询
在block和page中都要调用current_posts_contents($display)。
把current_posts_contents中的注释打开

3.7 主题化page
function _current_posts_page(){ drupal_set_title('Current posts'); $result = current_posts_contents('page'); $items = array(); foreach ($result as $node) { $items[] = array( 'data' => l($node->title, 'node/' . $node->nid), ); } if (empty($items)) { $page_array['current_posts_arguments'] = array( '#title' => t('All posts from the last week'), '#markup' => t('No posts available.'), ); return $page_array; } else { $page_array['current_posts_arguments'] = array( '#title' => t('All posts from the last week'), '#items' => $items, //Theme function includes theme hook suggestion. '#theme' => 'item_list__current_posts', ); return $page_array; }}注意'theme' => 'item_list__current_posts'会调用theme_item_list__current_posts主题函数。条件是实现了theme_hook, 在theme_hookl里注册item_list__current_posts, 同时提供了theme_item_list_current_posts函数function current_posts_theme(){ return array( 'item_list__current_posts' => array( //模板优先theme_item_list__current_posts调用 //如果设置了template，就不调用theme_item_list_current_posts (猜的， 不确定) 'template' => 'ludonghai', //调用sites/all/module/current_posts/ludonghai.tpl.php 'render element' => 'element', //在模板里可以调用的变量 ) ); }function theme_item_list__current_posts(){ return "hello";} 

注意：在修改hook之后必须reenable module在可以, drupal会把实现的hook存到数据库中

 

完整current_posts.module文件请猛击此处