#455844 by yched, JohnAlbin, moshe weitzman, Frando, et al: Allow more granular theming of drupal_render()ed elements.

2 files changed, 76 insertions, 17 deletions

diff --git a/includes/common.inc b/includes/common.inc
index a926d019d..a1996a189 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -3748,6 +3748,56 @@ function drupal_render_children(&$element, $children_keys = NULL) {
 }
 
 /**
+ * Render and print an element.
+ *
+ * This function renders an element using drupal_render() and then prints out
+ * the rendered output. The top level element is always rendered and printed
+ * even if hide() had been previously used on it.
+ *
+ * Any nested elements are only printed if they haven't been printed before or
+ * if they have been re-enabled with show(). If the element is a string instead
+ * of a renderable array it is also printed.
+ *
+ * @see drupal_render()
+ * @see show()
+ * @see hide()
+ */
+function render(&$element) {
+  if (is_array($element)) {
+    show($element);
+    print drupal_render($element);
+  }
+  else {
+    print $element;
+  }
+}
+
+/**
+ * Hide an element from later rendering.
+ *
+ * @see render()
+ * @see show()
+ */
+function hide(&$element) {
+  $element['#printed'] = TRUE;
+  return $element;
+}
+
+/**
+ * Show a hidden or already printed element from later rendering.
+ *
+ * Alternatively, render($element) could be used which automatically shows the
+ * element while rendering and printing it.
+ *
+ * @see render()
+ * @see hide()
+ */
+function show(&$element) {
+  $element['#printed'] = FALSE;
+  return $element;
+}
+
+/**
  * Function used by uasort to sort structured arrays by weight.
  */
 function element_sort($a, $b) {
diff --git a/includes/theme.inc b/includes/theme.inc
index 59561c560..7558d2b1d 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -1886,7 +1886,7 @@ function template_process(&$variables, $hook) {
 }
 
 /**
- * Process variables for page.tpl.php
+ * Preprocess variables for page.tpl.php
  *
  * Most themes utilize their own copy of page.tpl.php. The default is located
  * inside "modules/system/page.tpl.php". Look in there for the full list of
@@ -1897,12 +1897,9 @@ function template_process(&$variables, $hook) {
  *
  * Any changes to variables in this preprocessor should also be changed inside
  * template_preprocess_maintenance_page() to keep all of them consistent.
- *
- * The $variables array contains two keys:
- * - 'page': the fully decorated page.
- * - 'content': the content of the page, already rendered.
- *
+ * 
  * @see drupal_render_page
+ * @see template_process_page
  * @see page.tpl.php
  */
 function template_preprocess_page(&$variables) {
@@ -1910,11 +1907,6 @@ function template_preprocess_page(&$variables) {
   $variables['show_blocks'] = $variables['page']['#show_blocks'];
   $variables['show_messages'] = $variables['page']['#show_messages'];
 
-  // Render each region into top level variables.
-  foreach (system_region_list($GLOBALS['theme']) as $region_key => $region_name) {
-    $variables[$region_key] = empty($variables['page'][$region_key]) ? '' : drupal_render($variables['page'][$region_key]);
-  }
-
   // Add favicon.
   if (theme_get_setting('toggle_favicon')) {
     $favicon = theme_get_setting('favicon');
@@ -1928,10 +1920,10 @@ function template_preprocess_page(&$variables) {
 
   // Set up layout variable.
   $variables['layout'] = 'none';
-  if (!empty($variables['left'])) {
+  if (!empty($variables['page']['left'])) {
     $variables['layout'] = 'left';
   }
-  if (!empty($variables['right'])) {
+  if (!empty($variables['page']['right'])) {
     $variables['layout'] = ($variables['layout'] == 'left') ? 'both' : 'right';
   }
 
@@ -1950,7 +1942,6 @@ function template_preprocess_page(&$variables) {
   $variables['front_page']        = url();
   $variables['breadcrumb']        = theme('breadcrumb', drupal_get_breadcrumb());
   $variables['feed_icons']        = drupal_get_feeds();
-  $variables['head']              = drupal_get_html_head();
   $variables['language']          = $GLOBALS['language'];
   $variables['language']->dir     = $GLOBALS['language']->direction ? 'rtl' : 'ltr';
   $variables['logo']              = theme_get_setting('logo');
@@ -1960,9 +1951,6 @@ function template_preprocess_page(&$variables) {
   $variables['search_box']        = (theme_get_setting('toggle_search') ? drupal_render(drupal_get_form('search_theme_form')) : '');
   $variables['site_name']         = (theme_get_setting('toggle_name') ? filter_xss_admin(variable_get('site_name', 'Drupal')) : '');
   $variables['site_slogan']       = (theme_get_setting('toggle_slogan') ? filter_xss_admin(variable_get('site_slogan', '')) : '');
-  $variables['css']               = drupal_add_css();
-  $variables['styles']            = drupal_get_css();
-  $variables['scripts']           = drupal_get_js();
   $variables['tabs']              = theme('menu_local_tasks');
   $variables['title']             = drupal_get_title();
   // RDFa allows annotation of XHTML pages with RDF data, while GRDDL provides
@@ -2014,6 +2002,27 @@ function template_preprocess_page(&$variables) {
     $variables['classes_array'][] = 'one-sidebar sidebar-' . $variables['layout'];
   }
 }
+/**
+ * Process variables for page.tpl.php
+ *
+ * Perform final addition and modification of variables before passing into 
+ * the template. To customize these variables, call drupal_render() on elements 
+ * in $variables['page'] during THEME_preprocess_page().
+ *
+ * @see template_preprocess_page()
+ * @see page.tpl.php
+ */
+function template_process_page(&$variables) {
+  // Render each region into top level variables.
+  foreach (system_region_list($GLOBALS['theme']) as $region_key => $region_name) {
+    $variables[$region_key] = drupal_render($variables['page'][$region_key]);
+  }
+
+  $variables['head']    = drupal_get_html_head();
+  $variables['css']     = drupal_add_css();
+  $variables['styles']  = drupal_get_css();
+  $variables['scripts'] = drupal_get_js();
+}
 
 /**
  * Generate an array of page template suggestions.