lazyloader.module in Image Lazyloader 7.2
Same filename and directory in other branches
Lazyloader Module
@author: Daniel Honrade http://drupal.org/user/351112
Note: Obviously, this will not work unless the javascript is on.
File
lazyloader.moduleView source
<?php
/**
* @file
* Lazyloader Module
*
* @author: Daniel Honrade http://drupal.org/user/351112
*
* Note: Obviously, this will not work unless the javascript is on.
*
*/
define("LAZYLOADER_ENABLED", TRUE);
define("LAZYLOADER_DISTANCE", 250);
define("LAZYLOADER_ICON", 7);
define("LAZYLOADER_CUSTOM_ICON_PATH", '');
define("LAZYLOADER_PLACEHOLDER", '');
define("LAZYLOADER_PATHS", "media/*/format-form\nadmin/*\nnode/add/*\nnode/*/edit");
define("LAZYLOADER_EXCLUDED_FILENAMES", '');
define("LAZYLOADER_PAGE_EXCLUDE_OPTION", 'exclude');
define("LAZYLOADER_CONTENT_TYPE_EXCLUDE_OPTION", 'exclude');
define("LAZYLOADER_LOAD_IMAGE_DELAY", 50);
define("LAZYLOADER_DEBOUNCE", TRUE);
define("LAZYLOADER_UNLOAD", FALSE);
define("LAZYLOADER_DEBUGGING", FALSE);
/**
* Implements hook_menu().
*
*/
function lazyloader_menu() {
$items = array();
$items['admin/config/media/lazyloader'] = array(
'title' => 'Image Lazyloader',
'page callback' => 'drupal_get_form',
'access callback' => 'user_access',
'access arguments' => array(
'administer lazyloader',
),
'page arguments' => array(
'lazyloader_admin_configure',
NULL,
),
'type' => MENU_NORMAL_ITEM,
'file' => 'lazyloader.admin.inc',
'description' => 'Configure Lazyloader',
);
$items['admin/config/media/lazyloader/configure'] = array(
'title' => 'Configure',
'type' => MENU_DEFAULT_LOCAL_TASK,
'description' => 'Configure Lazyloader settings',
);
$items['admin/config/media/lazyloader/exclude'] = array(
'title' => 'Exclude options',
'page callback' => 'drupal_get_form',
'access callback' => 'user_access',
'access arguments' => array(
'administer lazyloader',
),
'page arguments' => array(
'lazyloader_admin_exclude',
NULL,
),
'type' => MENU_LOCAL_TASK,
'file' => 'lazyloader.admin.inc',
'description' => 'Configure Lazyloader inclusion/exclusion settings',
);
return $items;
}
/**
* Implements hook_perm().
*
*/
function lazyloader_permission() {
return array(
'administer lazyloader' => array(
'title' => t('Administer Lazyloader'),
'description' => t('Perform administration tasks for Lazyloader.'),
),
);
}
/**
* Implements hook_theme().
*/
function lazyloader_theme($existing, $type, $theme, $path) {
$info = array();
if (isset($existing['image']['variables'])) {
$info['lazyloader_image'] = array(
'variables' => $existing['image']['variables'],
'function' => 'theme_lazyloader_image',
);
}
return $info;
}
/**
* Implements hook_theme_registry_alter().
*/
function lazyloader_theme_registry_alter(&$theme_registry) {
if (variable_get('lazyloader_enabled', LAZYLOADER_ENABLED)) {
$theme_registry['image']['function'] = 'theme_lazyloader_image';
}
return $theme_registry;
}
/**
* Returns HTML for an image.
*
* @param $variables
* An associative array containing:
* - path: Either the path of the image file (relative to base_path()) or a
* full URL.
* - width: The width of the image (if known).
* - height: The height of the image (if known).
* - alt: The alternative text for text-based browsers. HTML 4 and XHTML 1.0
* always require an alt attribute. The HTML 5 draft allows the alt
* attribute to be omitted in some cases. Therefore, this variable defaults
* to an empty string, but can be set to NULL for the attribute to be
* omitted. Usually, neither omission nor an empty string satisfies
* accessibility requirements, so it is strongly encouraged for code calling
* theme('image') to pass a meaningful value for this variable.
* - http://www.w3.org/TR/REC-html40/struct/objects.html#h-13.8
* - http://www.w3.org/TR/xhtml1/dtds.html
* - http://dev.w3.org/html5/spec/Overview.html#alt
* - title: The title text is displayed when the image is hovered in some
* popular browsers.
* - attributes: Associative array of attributes to be placed in the img tag.
* @return string
* HTML for a lazyloaded image
*/
function theme_lazyloader_image($variables) {
$theme_image = theme_image($variables);
// Use theme_image if lazyloader is not enabled.
if ($variables['theme_hook_original'] !== 'lazyloader_image') {
if (!_lazy_loader_enabled() || _lazyloader_excluded_by_filename($variables) || _lazyloader_excluded_by_image_style($variables)) {
return $theme_image;
}
}
static $rdwimages_enabled, $image_placeholder_src;
$attributes = $variables['attributes'];
// Set the data source and placeholder image.
$attributes['data-echo'] = file_create_url($variables['path']);
$attributes['data-icon'] = _lazyloader_icon_path();
if (!isset($image_placeholder_src)) {
// Path to dummy placeholder image, to be replaced by actual image.
$image_placeholder = trim(variable_get('lazyloader_placeholder', LAZYLOADER_PLACEHOLDER));
$image_placeholder_src = $image_placeholder ? base_path() . $image_placeholder : file_create_url(drupal_get_path('module', 'lazyloader') . '/image_placeholder.gif');
}
// Integrate with Responsive Webdesign module.
if (!isset($rdwimages_enabled)) {
global $_rwdimages_set;
$rdwimages_enabled = module_exists('rdwimages') && $_rwdimages_set['enabled'];
}
if ($rdwimages_enabled) {
$attributes['class'] = isset($attributes['class']) ? $attributes['class'] + array(
'rwdimage',
) : array(
'rdwimage',
);
}
// Add noscript as a fallback.
$noscript = "<noscript>{$theme_image}</noscript>";
$arguments = array(
'path' => $image_placeholder_src,
'attributes' => $attributes,
);
foreach (array(
'width',
'height',
'alt',
'title',
) as $key) {
if (isset($variables[$key])) {
$arguments[$key] = $variables[$key];
}
}
// Get the icon width and height for use in the javascript.
$icon_path = substr(_lazyloader_icon_path(), strlen(base_path()));
// The path will be empty if the user configured the option to show no icon.
list($icon_width, $icon_height) = !empty($icon_path) ? getimagesize($icon_path) : array(
0,
0,
);
$settings['lazyloader'] = array(
'throttle' => variable_get('lazyloader_load_image_delay', LAZYLOADER_LOAD_IMAGE_DELAY),
'offset' => variable_get('lazyloader_distance', LAZYLOADER_DISTANCE),
'debounce' => variable_get('lazyloader_debounce', LAZYLOADER_DEBOUNCE),
'unload' => variable_get('lazyloader_unload', LAZYLOADER_UNLOAD),
'icon' => _lazyloader_icon_path(),
'offsetX' => $icon_width > 0 ? floor($icon_width / 2) : 0,
'offsetY' => $icon_height > 0 ? floor($icon_height / 2) : 0,
);
drupal_add_js($settings, array(
'type' => 'setting',
));
// Load the Echo library.
$variant = variable_get('lazyloader_debugging', LAZYLOADER_DEBUGGING) ? NULL : 'minified';
libraries_load_files(libraries_load('echo', $variant));
// Render the image.
return theme_image($arguments) . $noscript;
}
/**
* Helper function to determine whether the lazyloader is enabled in a page.
*
* @return bool
*/
function _lazy_loader_enabled() {
// Bail if lazyloader is disabled entirely.
if (!variable_get('lazyloader_enabled', LAZYLOADER_ENABLED)) {
return FALSE;
}
// This method gets called quite often, so let's cache all the heavy stuff.
static $enabled;
if (isset($enabled)) {
return $enabled;
}
// Convert path to lowercase. This allows comparison of the same path
// with different case. Ex: /Page, /page, /PAGE.
$pages = drupal_strtolower(variable_get('lazyloader_paths', LAZYLOADER_PATHS));
// Convert the Drupal path to lowercase
$path = drupal_strtolower(drupal_get_path_alias($_GET['q']));
// Compare the lowercase internal and lowercase path alias (if any).
$path_match = drupal_match_path($path, $pages);
if ($path != $_GET['q']) {
$path_match = $path_match || drupal_match_path($_GET['q'], $pages);
}
$path_exclude = variable_get('lazyloader_page_exclude_option', LAZYLOADER_PAGE_EXCLUDE_OPTION);
$enabled = $path_exclude === 'exclude' ? !$path_match : $path_match;
// Only check content types if Lazyloader is not disabled already.
if ($enabled && ($node = menu_get_object())) {
$types = _lazyloader_filter_selected_values(variable_get('lazyloader_content_types', array()));
if (!empty($types)) {
$type = node_type_get_type($node);
$type_match = in_array($type->type, $types);
$enabled = $type_match;
}
}
return $enabled;
}
/**
* Helper function to determine if an image should be excluded by filename.
*/
function _lazyloader_excluded_by_filename($variables) {
$excluded_files = preg_split("/\\r\\n|\\r|\\n/", variable_get('lazyloader_excluded_filenames', LAZYLOADER_EXCLUDED_FILENAMES));
$parts = explode('/', $variables['path']);
$parts = explode('?', array_pop($parts));
$filename = array_shift($parts);
return (bool) in_array($filename, $excluded_files);
}
/**
* Helper function to determine if an image should be excluded by image style.
*/
function _lazyloader_excluded_by_image_style($variables) {
$excluded_styles = _lazyloader_filter_selected_values(variable_get('lazyloader_image_styles', array()));
// If no image styles are selected we have nothing to exclude.
if (empty($excluded_styles)) {
return FALSE;
}
$styles = implode('|', array_keys(image_styles()));
// Make sure the image is actually a derived image.
if (preg_match('/styles\\/[' . $styles . ']/', $variables['path'])) {
return (bool) (!in_array($variables['style_name'], $excluded_styles));
}
else {
// Not a derived image, nothing to do here.
return FALSE;
}
}
/**
* Helper function to get the loading icon.
*/
function _lazyloader_icon_path() {
$icon = variable_get('lazyloader_icon', LAZYLOADER_ICON);
$custom_icon_path = variable_get('lazyloader_custom_icon_path', LAZYLOADER_CUSTOM_ICON_PATH);
if (!empty($icon)) {
$base = base_path();
if ($icon == 9) {
return "{$base}{$custom_icon_path}";
}
else {
$path = drupal_get_path('module', 'lazyloader');
return "{$base}{$path}/loader/loader-{$icon}.gif";
}
}
return '';
}
/**
* Implements hook_libraries_info().
*/
function lazyloader_libraries_info() {
$libraries['echo'] = array(
'name' => 'Echo',
'vendor url' => 'http://toddmotto.com/labs/echo/',
'download url' => 'https://github.com/toddmotto/echo/archive/master.zip',
'path' => 'dist',
'files' => array(
'js' => array(
'echo.js',
),
),
'integration files' => array(
'lazyloader' => array(
'js' => array(
'lazyloader.js',
),
),
),
'variants' => array(
'minified' => array(
'files' => array(
'js' => array(
'echo.min.js',
),
),
),
),
);
return $libraries;
}
/**
* Filters an array of selected checkbox values.
*/
function _lazyloader_filter_selected_values($values) {
// Filter out deselected values.
foreach ($values as $key => $value) {
if (!$value) {
unset($values[$key]);
}
}
return $values;
}Functions
Name |
Description |
|---|---|
| lazyloader_libraries_info | Implements hook_libraries_info(). |
| lazyloader_menu | Implements hook_menu(). |
| lazyloader_permission | Implements hook_perm(). |
| lazyloader_theme | Implements hook_theme(). |
| lazyloader_theme_registry_alter | Implements hook_theme_registry_alter(). |
| theme_lazyloader_image | Returns HTML for an image. |
| _lazyloader_excluded_by_filename | Helper function to determine if an image should be excluded by filename. |
| _lazyloader_excluded_by_image_style | Helper function to determine if an image should be excluded by image style. |
| _lazyloader_filter_selected_values | Filters an array of selected checkbox values. |
| _lazyloader_icon_path | Helper function to get the loading icon. |
| _lazy_loader_enabled | Helper function to determine whether the lazyloader is enabled in a page. |