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<?php
/**
* @file
* Explains how a module declares theme functions, preprocess functions, and
* templates.
*
* The underlying approach is that a module should allow themes to do all
* rendering, but provide default implementations where appropriate.
*
* Modules are also expected to leave data as render arrays as long as possible,
* leaving rendering to theme functions and templates.
*/
/**
* @defgroup theming_example Example: Theming
* @ingroup examples
* @{
* Example of Drupal theming.
*
* The theming_example module attempts to show how module developers can add
* theme functions to their projects so that themes can modify output.
*
* Module developers should to strive to avoid hard-wiring any HTML into the
* output of their code, this should all be done in theme functions.
*
* Starting with the first example, function 'theming_example_page()':
* the output is put into an array $content which is then fed to a theming
* function 'theme_theming_example_content_array()' which loops over the
* content, wrapping it in html in the process.
*
* In order to get function 'theme_theming_example_content_array()' recognized
* it needs to be registered with the module theme register function of the type
* 'hook_theme'.
*
* function 'theming_example_theme()' does this for this module.
* for details of what can be done in this hook see the link to api.drupal.org
*
* The functions 'theming_example_list_page()' and theming_example_order_form()
* work in the same way.
*
* In 'theme_theming_example_list_page()' the content is themed as an
* ordered list and given a class attribute 'theming_example_mylist' which
* is defined in theming_example.css
*
* In function 'theme_theming_example_order_form()' the title is loaded into a
* temporary variable '$title', deleted from the $form array and output
* wrapped in html. The rest of the form is wrapped in a div using '#prefix'
* and '#suffix'
*
* The theming functions can be copied to a theme's template.php, renaming
* appropriately, so if your theme is called 'mytheme' you would copy function
* 'theme_theming_example_content_array()' to function
* 'mytheme_theming_example_page()' in template.php and it will be used instead
* of the original.
*
* The fourth example shows the use of a template file
* 'theming_example_text_form.tpl.php'
* This file can be copied to a theme's folder and it will be used instead.
*
* This example also shows what can be done using Drupal's
* template_preprocess_HOOK method. In this case it modifies the output so
* that a themer can output the whole form or gain control over some of its
* parts in the template file.
*/
/**
* Implements hook_menu().
*
* The @link menu_example.module Menu Example @endlink provides extensive
* examples for hook_menu().
*/
function theming_example_menu() {
$items['examples/theming_example'] = array(
'title' => 'Theming Example',
'description' => 'Some theming examples.',
'page callback' => 'theming_example_page',
'access callback' => TRUE,
'access arguments' => array('access content'),
);
$items['examples/theming_example/theming_example_list_page'] = array(
'title' => 'Theming a list',
'page callback' => 'theming_example_list_page',
'access arguments' => array('access content'),
'weight' => 1,
);
$items['examples/theming_example/theming_example_select_form'] = array(
'title' => 'Theming a form (select form)',
'page callback' => 'drupal_get_form',
'page arguments' => array('theming_example_select_form'),
'access arguments' => array('access content'),
'weight' => 2,
);
$items['examples/theming_example/theming_example_text_form'] = array(
'title' => 'Theming a form (text form)',
'page callback' => 'drupal_get_form',
'page arguments' => array('theming_example_text_form'),
'access arguments' => array('access content'),
'weight' => 3,
);
return $items;
}
/**
* Implements hook_theme().
*
* Defines the theming capabilities provided by this module.
*/
function theming_example_theme($existing, $type, $theme, $path) {
return array(
'theming_example_content_array' => array(
// We use 'render element' when the item to be passed is a self-describing
// render array (it will have #theme_wrappers)
'render element' => 'element',
),
'theming_example_list' => array(
// We use 'variables' when the item to be passed is an array whose
// structure must be described here.
'variables' => array(
'title' => NULL,
'items' => NULL,
),
),
'theming_example_select_form' => array(
'render element' => 'form',
),
'theming_example_text_form' => array(
'render element' => 'form',
// In this one the rendering will be done by a template file
// (theming-example-text-form.tpl.php) instead of being rendered by a
// function. Note the use of dashes to separate words in place of
// underscores. The template file's extension is also left out so that
// it may be determined automatically depending on the template engine
// the site is using.
'template' => 'theming-example-text-form',
),
);
}
/**
* Initial landing page explaining the use of the module.
*
* We create a render array and specify the theme to be used through the use
* of #theme_wrappers. With all output, we aim to leave the content as a
* render array just as long as possible, so that other modules (or the theme)
* can alter it.
*
* @see render_example.module
* @see form_example_elements.inc
*/
function theming_example_page() {
$content[]['#markup'] = t('Some examples of pages and forms that are run through theme functions.');
$content[]['#markup'] = l(t('Simple page with a list'), 'examples/theming_example/theming_example_list_page');
$content[]['#markup'] = l(t('Simple form 1'), 'examples/theming_example/theming_example_select_form');
$content[]['#markup'] = l(t('Simple form 2'), 'examples/theming_example/theming_example_text_form');
$content['#theme_wrappers'] = array('theming_example_content_array');
return $content;
}
/**
* The list page callback.
*
* An example page where the output is supplied as an array which is themed
* into a list and styled with css.
*
* In this case we'll use the core-provided theme_item_list as a #theme_wrapper.
* Any theme need only override theme_item_list to change the behavior.
*/
function theming_example_list_page() {
$items = array(
t('First item'),
t('Second item'),
t('Third item'),
t('Fourth item'),
);
// First we'll create a render array that simply uses theme_item_list.
$title = t("A list returned to be rendered using theme('item_list')");
$build['render_version'] = array(
// We use #theme here instead of #theme_wrappers because theme_item_list()
// is the classic type of theme function that does not just assume a
// render array, but instead has its own properties (#type, #title, #items).
'#theme' => 'item_list',
// '#type' => 'ul', // The default type is 'ul'
// We can easily make sure that a css or js file is present using #attached.
'#attached' => array('css' => array(drupal_get_path('module', 'theming_example') . '/theming_example.css')),
'#title' => $title,
'#items' => $items,
'#attributes' => array('class' => array('render-version-list')),
);
// Now we'll create a render array which uses our own list formatter,
// theme('theming_example_list').
$title = t("The same list rendered by theme('theming_example_list')");
$build['our_theme_function'] = array(
'#theme' => 'theming_example_list',
'#attached' => array('css' => array(drupal_get_path('module', 'theming_example') . '/theming_example.css')),
'#title' => $title,
'#items' => $items,
);
return $build;
}
/**
* A simple form that displays a select box and submit button.
*
* This form will be be themed by the 'theming_example_select_form' theme
* handler.
*/
function theming_example_select_form($form, &$form_state) {
$options = array(
'newest_first' => t('Newest first'),
'newest_last' => t('Newest last'),
'edited_first' => t('Edited first'),
'edited_last' => t('Edited last'),
'by_name' => t('By name'),
);
$form['choice'] = array(
'#type' => 'select',
'#options' => $options,
'#title' => t('Choose which ordering you want'),
);
$form['submit'] = array(
'#type' => 'submit',
'#value' => t('Go'),
);
return $form;
}
/**
* Submit handler for the select form.
*
* @param array $form
* Form API form array.
* @param array $form_state
* Form API form state array.
*/
function theming_example_select_form_submit($form, &$form_state) {
drupal_set_message(t('You chose %input', array('%input' => $form_state['values']['choice'])));
}
/**
* A simple form that displays a textfield and submit button.
*
* This form will be rendered by theme('form') (theme_form() by default)
* because we do not provide a theme function for it here.
*/
function theming_example_text_form($form, &$form_state) {
$form['text'] = array(
'#type' => 'textfield',
'#title' => t('Please input something!'),
'#required' => TRUE,
);
$form['submit'] = array(
'#type' => 'submit',
'#value' => t('Go'),
);
return $form;
}
/**
* Submit handler for the text form.
*
* @param array $form
* Form API form array.
* @param array $form_state
* Form API form state array.
*/
function theming_example_text_form_submit($form, &$form_state) {
drupal_set_message(t('You entered %input', array('%input' => $form_state['values']['text'])));
}
/**
* Theme a simple content array.
*
* This theme function uses the newer recommended format where a single
* render array is provided to the theme function.
*/
function theme_theming_example_content_array($variables) {
$element = $variables['element'];
$output = '';
foreach (element_children($element) as $count) {
if (!$count) {
// The first paragraph is bolded.
$output .= '<p><strong>' . $element[$count]['#children'] . '</strong></p>';
}
else {
// Following paragraphs are just output as routine paragraphs.
$output .= '<p>' . $element[$count]['#children'] . '</p>';
}
}
return $output;
}
/**
* Theming a simple list.
*
* This is just a simple wrapper around theme('item_list') but it's worth
* showing how a custom theme function can be implemented.
*
* @see theme_item_list()
*/
function theme_theming_example_list($variables) {
$title = $variables['title'];
$items = $variables['items'];
// Add the title to the list theme and
// state the list type. This defaults to 'ul'.
// Add a css class so that you can modify the list styling.
// We'll just call theme('item_list') to render.
$variables = array(
'items' => $items,
'title' => $title,
'type' => 'ol',
'attributes' => array('class' => 'theming-example-list'),
);
$output = theme('item_list', $variables);
return $output;
}
/**
* Theming a simple form.
*
* Since our form is named theming_example_select_form(), the default
* #theme function applied to is will be 'theming_example_select_form'
* if it exists. The form could also have specified a different
* #theme.
*
* Here we collect the title, theme it manually and
* empty the form title. We also wrap the form in a div.
*/
function theme_theming_example_select_form($variables) {
$form = $variables['form'];
$title = $form['choice']['#title'];
$form['choice']['#title'] = '';
$output = '<strong>' . $title . '</strong>';
$form['choice']['#prefix'] = '<div class="container-inline">';
$form['submit']['#suffix'] = '</div>';
$output .= drupal_render_children($form);
return $output;
}
/**
* Implements template_preprocess().
*
* We prepare variables for use inside the theming-example-text-form.tpl.php
* template file.
*
* In this example, we create a couple new variables, 'text_form' and
* 'text_form_content', that clean up the form output. Drupal will turn the
* array keys in the $variables array into variables for use in the template.
*
* So $variables['text_form'] becomes available as $text_form in the template.
*
* @see theming-example-text-form.tpl.php
*/
function template_preprocess_theming_example_text_form(&$variables) {
$variables['text_form_content'] = array();
$text_form_hidden = array();
// Each form element is rendered and saved as a key in $text_form_content, to
// give the themer the power to print each element independently in the
// template file. Hidden form elements have no value in the theme, so they
// are grouped into a single element.
foreach (element_children($variables['form']) as $key) {
$type = $variables['form'][$key]['#type'];
if ($type == 'hidden' || $type == 'token') {
$text_form_hidden[] = drupal_render($variables['form'][$key]);
}
else {
$variables['text_form_content'][$key] = drupal_render($variables['form'][$key]);
}
}
$variables['text_form_content']['hidden'] = implode($text_form_hidden);
// The entire form is then saved in the $text_form variable, to make it easy
// for the themer to print the whole form.
$variables['text_form'] = implode($variables['text_form_content']);
}
/**
* @} End of "defgroup theming_example".
*/