The document introduces the Render API in Drupal 7. It discusses how the Render API works similarly to the Form API by collecting necessary data into an array that is then converted to HTML and displayed. It describes main hooks like hook_page_build() and hook_page_alter() that can be used to add or override page elements. It also provides examples of using #theme and #arguments to theme render arrays and attach CSS/JS files.

1. Render API in Drupal7
Shmaleniuk Nikolay
n.shmaleniuk@gmail.com

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4. Render API introduction
Render API similar to the work of the Form API.
1. The system collects an array which contains all the
necessary data
– Array data converted to html and displayed

5. Main hooks
• hook_page_build
add items to the page
• hook_page_alter
override the output of all page elements before output

7. dsm(hook_page_alter_data)

10. Render API theming
• #theme - theme_function to be called
• #arg_1, #arg_2 - arguments with prefix "#", necessary for the
theme function

11. The advantages of using
• One general system of generating output data
• All html on the page, can be easily overridden by using a one
hook
• Reusability code. Reusability the menu callbacks or blocks
for the their tasks (eg AJAX replies)
• Caching

12. 3 types of element
1. Standerd element, key #type (hook_element_info())
2. Text data, key #markup
3. Theme element, key #theme

13. Example, node.tpl.php
render(), show(), hide()
<?php
hide($content['comments']);
hide($content['links']);
print render($content);
?>
<?php if (!empty($content['links'])): ?>
<div class="links"><?php print render($content['links']); ?>
</div>
<?php endif; ?>
<?php print render($content['comments']); ?>

14. Example
// Drupal 6.
function my_module_show_same_items() {
$items = array('item 1', 'item 2', 'item 3');
$out = theme('item_list', $items);
return $out;
}
// Drupal 7.
function my_module_show_some_items() {
$items = array('item 1', 'item 2', 'item 3');
$build = array(
'items' => array('#theme' => 'item_list', '#items' => $items),
);
return $build;
}

15. Example
function theme_pager_link($variables) {
$var_text = $variables['var'];
$var_page_new = $variables['var_2'];
... }
function my_module_show_some_text() {
$item = array(
'items' => array(
'#theme' => 'pager_link',
'#var' => 'some text',
'#var_2' => '...',
),
);
return $item;
}

16. The array keys Render API
• #access - TRUE or FALSE
• #type - str
• #printed - TRUE or FALSE
• #cache - array()
• #theme - str
• #theme_wrappers - array()
• #pre_render - array()
• #post_render - array()
• #attached - array()
• #prefix, #suffix - str

17. Sequence of actions drupal_render()
1. Checking #access и #printed
2. Checking the cache
3. Loading the default item (if #type)
4. Call #pre_render
5. Call #theme
6. Call #theme_wrappers
7. Call #post_render
8. Load attached recurses #attached (JS, CSS, etc.)
9. If #cache set, the write cache
10.return #prefix . $out . #suffix;

18. Attached recurses, JS/CSS files
$form['#attached']['css'] = array(
drupal_get_path('module', 'ajax_example') .
'/ajax_example.css',
);
$form['#attached']['js'] = array(
drupal_get_path('module', 'ajax_example') . '/ajax_example.js',
);

19. Attached recurses, JS settings
$settings = array('id' => 'mymodule-element-1');
$form['#attached']['js'][] = array(
'data' => array('mymodule' => $settings),
'type' => 'setting',
);

20. Attached recurses, http header
and library
$form['#attached']['drupal_add_http_header'] = array(
array('Content-Type', 'application/rss+xml; charset=utf-8'),
);
$form['#attached']['library'][] = array('system', 'drupal.ajax');

21. Caching
$build = array(
'items' => array(
'#theme' => 'item_list',
'#items' => $items,
'#cache' => array(
'keys' => array('example', 'cache'),
'bin' => 'cache',
'expire' => time() + $interval,
'granularity' => DRUPAL_CACHE_PER_PAGE |
DRUPAL_CACHE_PER_ROLE,
),
),
);

22. Caching
$items = module_load_item_list();
$build = array(
'items' => array(
'#theme' => 'item_list',
'#items' => $items,
'#cache' => array(
'keys' => array('example', 'cache'),
'bin' => 'cache',
'expire' => time() + $interval,
'granularity' => DRUPAL_CACHE_PER_PAGE |
DRUPAL_CACHE_PER_ROLE,
),
),
);

23. Caching
$build = array(
'items' => array(
'#theme' => 'item_list',
'#pre_render' => array( 'module_load_item_list'),
'#items' => array(),
'#cache' => array(
'keys' => array('example', 'cache'),
'granularity' => DRUPAL_CACHE_PER_PAGE,
),
),
);
function module_load_item_list(&$element) {
$element['#items'] = module_load_item_list();
}

24. • Render Arrays in Drupal
http://drupal.org/node/930760
• Examples
http://drupal.org/project/examples
Shmaleniuk Nikolay
n.shmaleniuk@gmail.com