/**
 * @file
 * A silly module to assist whizbang novelists who are in a rut by providing a
 * random sentence generator for their posts.
 */

/**
 * Implementation of hook_filter().
 */
function creativejuice_filter($op, $delta = 0, $format = -1, $text = '') {
  switch ($op) {
    case 'list':
      return array(
        0 => t('Creative Juices filter'),
        1 => t('The name of my second filter'),
      );

    case 'description':
      switch ($delta) {
        case 0:
          return t('Enables users to insert random sentences into their posts.');
        case 1:
          return t('If this module provided a second filter, the description for that second filter would go here.');
        // Should never return here as value of $delta never exceeds the last index of the 'list' array.
        default:
          return;
      }
      break;

    case 'settings':
        // No settings user interface for this filter.
      break;

    case 'no cache':
      return FALSE;

    case 'prepare':
      return $text;

    case 'process':
      return preg_replace_callback("|\[juice!\]|i", 'creativejuice_sentence', $text);

    default:
      return $text;
  }
}

/**
 * Generate a random sentence.
 */
function creativejuice_sentence() {
  $phrase[0][] = t('A majority of us believe');
  $phrase[0][] = t('Generally speaking,');
  $phrase[0][] = t('As times carry on');
  $phrase[0][] = t('Barren in intellect,');
  $phrase[0][] = t('Deficient in insight,');
  $phrase[0][] = t('As blazing blue sky poured down torrents of light,');
  $phrase[0][] = t('Aloof from the motley throng,');
  $phrase[1][] = t('life flowed in its accustomed stream');
  $phrase[1][] = t('he ransacked the vocabulary');
  $phrase[1][] = t('the grimaces and caperings of buffoonery');
  $phrase[1][] = t('the mind freezes at the thought');
  $phrase[1][] = t('she reverted to another matter');
  $phrase[1][] = t('he lived as modestly as a hermit');

  $phrase[2][] = t('through the red tape of officialdom.');
  $phrase[2][] = t('as it set anew in some fresh and appealing form.');
  $phrase[2][] = t('supported by evidence.');
  $phrase[2][] = t('as fatal as the fang of the most venomous snake.');
  $phrase[2][] = t('as full of spirit as a gray squirrel.');
  $phrase[2][] = t('as dumb as a fish.');
  $phrase[2][] = t('like a damp-handed auctioneer.');
  $phrase[2][] = t('like a bald ferret.');

  foreach ($phrase as $key => $value) {
    $rand_key = array_rand($phrase[$key]);
    $sentence[] = $phrase[$key][$rand_key];
  }

  return implode(' ', $sentence);
}

/**
 * Implementation of hook_filter_tips().
 */
function creativejuice_filter_tips($delta, $format, $long = FALSE) {
  if ($long) {
    // Detailed explanation for http://example.com/?q=filter/tips page.
    return t('The Creative Juices filter is for those times when your brain is incapable of being creative. These time comes for everyone, when even strong coffee and a barrel of jelly beans does not create the desired effect. When that happens, you can simply enter the [juice!] tag into your posts...');
  }
  else {
    // Short explanation for underneath a post's textarea.
    return t('Insert a random sentence into your post with the [juice!] tag.');
  }
}

blogstatus 0 1 db_rewrite_sql()db_fetch_object()db_fetch_array()3Getting a Limited Range of Results

$type = 'blog';

$status = 1;

$sql = "SELECT * FROM {node} n WHERE type = '%s' AND status = %d ORDER BY

n.created DESC";

$result = db_query_range(db_rewrite_sql($sql), $type, $status, 0, 10);

4Getting Results for Paged Display

$sql = "SELECT * FROM {node} n WHERE type = 'blog' AND status = 1 ORDER BY

n.created DESC"

$result = pager_query(db_rewrite_sql($sql), 0, 10);

while ($data = db_fetch_object($result)) {

$node = node_load($data->nid);

print node_view($node, TRUE);

}

// Add links to remaining pages of results.

print theme('pager', NULL, 10);

5Deleting Tables on Uninstall

âž?Modules page has an Uninstall tab that not only allows modules to be disabled,but also removes their data from the database. If you want to enable the deletion of your module’s tables on this page, implement the uninstall hook in your module’s .install file. You might want to delete any variables you’ve defined at the same time.

function annotate_uninstall() {

db_query("DROP TABLE {annotations}");

variable_del('annotate_nodetypes');

}

6Writing Your Own Database Abstraction Layer

_db_query($query, $debug = 0)

db_affected_rows()

db_connect($url)

db_decode_blob($data)

db_distinct_field($table, $field, $query)

db_encode_blob($data)

db_error()

db_escape_string($text)

db_fetch_array($result)

db_fetch_object($result)

db_lock_table($table)

db_next_id($name)

db_num_rows($result)

db_query_range($query)

db_query_temporary($query)

db_result($result, $row = 0)

db_status_report($phase)

db_table_exists($table)

db_unlock_tables()

db_version()

Usually menu access is controlled by defining permissions inside the

module using hook_perm() and testing those permissions using user_access().

function mymenu_perm() {

       return array('receive greeting', 'receive goodbye');

}

function mymenu_menu($may_cache) {

       $items = array();

       if ($may_cache) {

              // Define a static menu item.

              $items[] = array(

                     'title' => t('Greeting'),

                     'path' => 'mymenu',

                     'weight' => -10,

                     'callback' => 'mymenu_hello',

                     'callback arguments' => array(t('Hi!'), t('Ho!')),

                     'access' => user_access('receive greeting')

              );

              $items[] = array(

                     'title' => t('Farewell'),

                     'path' => 'mymenu/goodbye',

                     'callback' => 'mymenu_goodbye',

                     'access' => user_access('receive goodbye')

              );

       }

       return $items;

}

Assigning Callbacks Without Adding a Link to the Menu

Often you may want to map a URL to a function without creating a visible menu item. You

can do this by assigning the MENU_CALLBACK type to your menu item, as in this example from

node.module:

$items[] = array(

       'path' => 'rss.xml',

       'title' => t('RSS feed'),

       'callback' => 'node_feed',

       'access' => user_access('access content'),

       'type' => MENU_CALLBACK

);

Displaying Menu Items As Tabs

In Drupal’s admittedly obscure menu lingo, a callback that is displayed as a tab is known as a

local task and has the type MENU_LOCAL_TASK or MENU_DEFAULT_LOCAL_TASK. The title of a local

task should be a short verb, such as “add” or “list.” Local tasks usually act on some kind of

object, such as a node, user, or workflow.

Local tasks must have a parent item in order for the tabs to be rendered. A common practice

is to assign a callback to a root path like milkshake, and then assign local tasks to paths that

extend that path, like milkshake/prepare, milkshake/drink, and so forth. Drupal has built-in

support for two levels of tabbed local tasks.

function milkshake_menu($may_cache) {

       $items = array();

       if ($may_cache) {

              $items[] = array(

                     'path' => 'milkshake',

                     'title' => t('Milkshake flavors'),

                     'callback' => 'milkshake_overview',

                     'access' => TRUE

              );

              $items[] = array(

                     'path' => 'milkshake/list',

                     'title' => t('List flavors'),

                     'type' => MENU_DEFAULT_LOCAL_TASK, //menu

                     'access' => TRUE,

                     'weight' => 0

              );

              $items[] = array(

                     'path' => 'milkshake/add',

                     'title' => t('Add flavors'),

                     'callback' => 'milkshake_add',

                     'type' => MENU_LOCAL_TASK,

                     'access' => TRUE,

                     'weight' => 1

              );

              $items[] = array(

                     'path' => 'milkshake/list/fruity',

                     'title' => t('Fruity flavors'),

                     'callback' => 'milkshake_list',

                     'type' => MENU_LOCAL_TASK,

                     'access' => TRUE,

              );

              $items[] = array(

                     'path' => 'milkshake/list/candy',

                     'title' => t('Candy flavors'),

                     'callback' => 'milkshake_list',

                     'type' => MENU_LOCAL_TASK,

                     'access' => TRUE,

              );

       }

       return $items;

}

function milkshake_overview() {

       $output = t('The following flavors are available...');

       // ... more code here

       return $output;

}

function milkshake_add() {

       return t('milkshake add');

}

If you want the menu item to show up in the administrative menu block, you have to make

the type a MENU_NORMAL_ITEM instead of a MENU_LOCAL_TASK. And if you want it to show up in both

places, use the following:

'type' => MENU_NORMAL_ITEM | MENU_LOCAL_TASK

Programmatically Modifying Existing Menus

1Wrapping Calls to Menu Items

/**

* Implementation of hook_menu().

*/

function mymodule_menu($may_cache) {

       $items = array();

       if (!$may_cache && module_exist('devel')) { // Make sure devel.module is enabled.

              $items[] = array(

                     'path' => 'devel/cache/clear', // Same path that devel.module uses.

                     'title' => t('Wrap cache clear'),

                     'callback' => 'mymodule_clear_cache',

                     'type' => MENU_CALLBACK,

                     'access' => user_access('access devel information') // Same as devel.module.

              );

       }

}

function mymodule_clear_cache() {

       drupal_set_message('We got called first!');

       // Wrap the devel function normally called.

       devel_cache_clear();

}

2Deleting Existing Menus

$items[] = array(

       'path' => 'node/add',

       'title' => t('This should not show up'),

       'callback' => 'drupal_not_found',

       'type' => MENU_CALLBACK

);

Adding to Existing Menus

$items[] = array(

       'path' => 'admin/user/user/eradicate',

       'title' => t('Eradicate all users'),

       'callback' => 'mymodule_eradicate_users',

       'type' => MENU_LOCAL_TASK,

       'access' => TRUE

);

drupal只有21個檔案在include裡頭åQŒæ¯‹Æ¡å¿…會loading進來åQŒå…¶ä»–的全都攑֜¨modulesã€?br /> 也就是說åQŒé™¤äº?ji¨£n)é‚£òqùNš»æª”案以外åQŒå…¨éƒ¨çš„æÞp¥¿éƒ½æŠŠä»–當成module在寫。諸如CMS最基本的功能，文章½Ž¡ç†ã€è©•è«–、討論區、分™å?..½{‰çš„功能åQŒå…¨éƒ¨éƒ½å¯«åœ¨module裡，include裡頭所提供的是各種a(ch¨£n)piåQŒæª”案處理函式、資料åín存取、表單生æˆ?..½{‰ç­‰åQŒé€™æ¨£çš„分層，module便可以專å¿?j¨©)的開發各種功能ã€?/p>

當然åQŒé€™æ¨£çš„架構不夠ä×o(h¨´)人注目。有­a±å¤šweb app架構åQŒå°æ–¼æ¨¡¾i?åQˆmoduleåQ‰ã€æ’ä»Óž¼ˆplug-inåQ?..½{‰çš„運作åQŒé€šå¸¸æ˜¯è®“他們各自為政，自己òq¹è‡ªå·Þqš„事情。多是用核心(j¨©)提供的objectå’ŒfunctionåQŒåŠ ä¸Šmodule自己™åå¤–çš„codeåQŒé”到module要做到的™åå¤–功能。但是drupalçš„æ ¸å¿?j¨©)運作卻不是如此ã€?/p>

drupal處理使用的程式為modules/user.module。如果今天想要在看ä‹É用者資料的同時åQŒä¹Ÿæƒ³çœ‹çœ‹æ‰€æœ‰ä‹É用者過åŽÈ?r¨´n)¼è¡¨æ–‡ç« çš„liståQŒé‚£è©²æ€Žéº¼å¯«å‘¢åQ?/p>

直接一é»?/strong>åQŒæ›´æ”¹user.modueåQŒåœ¨™å¯ç¤ºæ™‚，順便åŽÀL–‡ç« è³‡æ–™åín抓相關的資料åQŸç„¶è€Œé€™æ¨£åÖM¸æ˜¯ä¸€å€‹å¥½æ–¹å¼åQŒä»Šå¤©ä“Q何想要對使用者增加新功能的時候，都得trace一‹Æ¡user.moduleçš„codeåQŒçœ‹æ‡‚他在嘋(g¨°u)啥，然後把新的code安插在合適的地方... 最後可能增加user.module的複雜度åQŒå¢žåŠ ç¶­è­·é‚£æ”¯module的難度，共同開發時，更是一個危險的方式ã€?/p>

½W¬äºŒ½E®æ–¹å¼?/strong>åQŒé‡å¯«ä¸€å€‹æ–°çš„瀏覽頁面åQŒé‡æ–°å¯«ä¸€å€‹SELECT的語句，讓SELECT的時候除äº?ji¨£n)ä‹É用者資­aŠï¼Œä¹ŸæŠŠæ–‡ç« è³‡æ–™ä¸€èµähŠ“å‡ÞZ¾†åQŒç„¶å¾Œé¡¯½Cºåˆ°ä¸åŒçš„頁面。但是這樣很浪費，明明跟user.module重複的功能達åˆîC¸€åŠä»¥ä¸Šï¼Œé‚£æ˜¯ä¸æ˜¯ä¹‹å¾Œè¦æ–°å¢žåŠŸèƒ½ï¼Œéƒ½å¾—重寫一‹Æ¡å‘¢åQ?/p>

上面兩種方式在drupal中也都可以達成，然而熟æ‚(zh¨¨n)‰Drupalçš„ähåÖM¸æœƒå¦‚此。Drupalçš„é–‹ç™ÆD€…很聰明åQŒä»–的模¾i„ç³»¾i±ï¼ˆmodule systemåQ‰è€ƒæ…®åˆîCº†(ji¨£n)模組再利用這一點，每個模¾i„都視為可以再利用的資源åQŒåªè¦å¯«moduleçš„äh惛_¯«åQŒé€éŽæ¨¡çµ„¾pȝ®”(d¨¡ng)便可以跟所有的module交互作用ã€?/p>

½W¬ä¸‰½E®æ–¹å¼?/strong>ä»?code>modules/user.moduleç‚ÞZ¾‹åQŒä»–åÏx(ch¨®ng)˜¯è™•ç†åŒ…含新增、修攏V€åˆªé™¤ã€è¨»å†Šã€ç™»å…?...½{‰æ‰€æœ‰èˆ‡ä½¿ç”¨è€…相關的功能。在進行每個重要的功能時，user.module都會呼叫一個函式去掃所有的moduleåQŒçœ‹çœ‹æ˜¯å¦æœ‰å…¶ä»–çš„module要在user.module進行此動作時åQŒä¹Ÿé€²è¡Œä¸€äº›å…¶ä»–想要做的事情，這就是drupal重要çš?a rel="nofollow">Hook Systemã€?br /> example:
在drupal user.module裡頭可以扑ֈ°å¦‚下的程式碼

function user_view($uid = 0) {
// ... skip
// moudle_invoke掃描所有的module
// 看看有沒有modulename_user這個function
// 有個話ž®Þqœ‹'view'這個功能的部䆾要加上什éº?
foreach (module_list() as $module) {
if ($data = module_invoke($module, 'user', 'view', '', $account)) {
// do something...
}
}
// ... skip
}

所以，½W¬ä¸‰½E®æ–¹å¼ï¼Œä¸ç”¨é‡å¯«åQŒä¹Ÿä¸ç”¨æ”¹åˆ°user.moduleåQŒåªè¦è‡ªå·±æ–°å¢žmodule和寫一個functionåQŒä¾¿å¯ä»¥è¼•é¬†è®“瀏覽使用者資­aŠæ™‚åQŒåŠ ä¸ŠéŽå¾€æ–‡ç« ã€?br /> example:
新增自己的moduleåQŒèˆ‡hook system¾RŠå¯†é‹ä½œ
新增sample.module

function sample_user($type, &$edit, &$user, $category = NULL) {
if ($type == 'view') {
return /*過往文章åQŒåž‹åˆ¥ç‚ºä¸€é™£åˆ—*/;
}
}

這就是drupal把眾多主要功能都寫成module的原因，讓所有模¾i„之間都可以交互利用åQŒæˆ–是寫¾i¦åˆ¥äººåˆ©ç”¨ï¼Œæˆ–是利用別ähçš„moduleåQŒåƒ½Iæœ¨ä¸€æ¨£æŽ¨ç ŒæˆæƒŒ™¦çš„功能，åÕdˆä¸æµªè²»è³‡æºã€?/p>

參考資源：(x¨¬)
詳細的用法在åQ?br /> http://drupaldocs.org/api/head/function/hook_user
Module developer's guideåQ?br /> http://drupal.org/node/508

Eric.Zhou 2007-11-29 13:23 发表评论

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