content.inc

<?php


/**
 * @file
 * Contains the tools to handle pluggable content that can be used by other
 * applications such as Panels or Dashboard.
 *
 * See the context-content.html file in advanced help for documentation
 * of this tool.
 */

/**
 * Provide defaults for a content type.
 *
 * Currently we check for automatically named callbacks to make life a little
 * easier on the developer.
 */
function ctools_content_process(&$plugin, $info) {
    $function_base = $plugin['module'] . '_' . $plugin['name'] . '_content_type_';
    if (empty($plugin['render callback']) && function_exists($function_base . 'render')) {
        $plugin['render callback'] = $function_base . 'render';
    }
    if (empty($plugin['admin title'])) {
        if (function_exists($function_base . 'admin_title')) {
            $plugin['admin title'] = $function_base . 'admin_title';
        }
        else {
            $plugin['admin title'] = $plugin['title'];
        }
    }
    if (empty($plugin['admin info']) && function_exists($function_base . 'admin_info')) {
        $plugin['admin info'] = $function_base . 'admin_info';
    }
    if (!isset($plugin['edit form']) && function_exists($function_base . 'edit_form')) {
        $plugin['edit form'] = $function_base . 'edit_form';
    }
    if (!isset($plugin['add form']) && function_exists($function_base . 'add_form')) {
        $plugin['add form'] = $function_base . 'add_form';
    }
    if (!isset($plugin['add form']) && function_exists($function_base . 'edit_form')) {
        $plugin['add form'] = $function_base . 'edit_form';
    }
    if (!isset($plugin['description'])) {
        $plugin['description'] = '';
    }
    if (!isset($plugin['icon'])) {
        $plugin['icon'] = ctools_content_admin_icon($plugin);
    }
    // Another ease of use check:
    if (!isset($plugin['content types'])) {
        // If a subtype plugin exists, try to use it. Otherwise assume single.
        if (function_exists($function_base . 'content_types')) {
            $plugin['content types'] = $function_base . 'content_types';
        }
        else {
            $type = array(
                'title' => $plugin['title'],
                'description' => $plugin['description'],
                'icon' => ctools_content_admin_icon($plugin),
                'category' => $plugin['category'],
            );
            if (isset($plugin['required context'])) {
                $type['required context'] = $plugin['required context'];
            }
            if (isset($plugin['top level'])) {
                $type['top level'] = $plugin['top level'];
            }
            $plugin['content types'] = array(
                $plugin['name'] => $type,
            );
            if (!isset($plugin['single'])) {
                $plugin['single'] = TRUE;
            }
        }
    }
}

/**
 * Fetch metadata on a specific content_type plugin.
 *
 * @param mixed $content
 *   Name of a panel content type.
 *
 * @return
 *   An array with information about the requested panel content type.
 */
function ctools_get_content_type($content_type) {
    ctools_include('context');
    ctools_include('plugins');
    return ctools_get_plugins('ctools', 'content_types', $content_type);
}

/**
 * Fetch metadata for all content_type plugins.
 *
 * @return
 *   An array of arrays with information about all available panel content types.
 */
function ctools_get_content_types() {
    ctools_include('context');
    ctools_include('plugins');
    return ctools_get_plugins('ctools', 'content_types');
}

/**
 * Get all of the individual subtypes provided by a given content type. This
 * would be all of the blocks for the block type, or all of the views for
 * the view type.
 *
 * @param $type
 *   The content type to load.
 *
 * @return
 *   An array of all subtypes available.
 */
function ctools_content_get_subtypes($type) {
    static $cache = array();
    $subtypes = array();
    if (is_array($type)) {
        $plugin = $type;
    }
    else {
        $plugin = ctools_get_content_type($type);
    }
    if (empty($plugin) || empty($plugin['name'])) {
        return;
    }
    if (isset($cache[$plugin['name']])) {
        return $cache[$plugin['name']];
    }
    if (isset($plugin['content types'])) {
        $function = $plugin['content types'];
        if (is_array($function)) {
            $subtypes = $function;
        }
        elseif (function_exists($function)) {
            // Cast to array to prevent errors from non-array returns.
            $subtypes = (array) $function($plugin);
        }
    }
    // Walk through the subtypes and ensure minimal settings are
    // retained.
    foreach ($subtypes as $id => $subtype) {
        // Ensure that the 'subtype_id' value exists.
        if (!isset($subtype['subtype_id'])) {
            $subtypes[$id]['subtype_id'] = $id;
        }
        // Use exact name since this is a modify by reference.
        ctools_content_prepare_subtype($subtypes[$id], $plugin);
    }
    $cache[$plugin['name']] = $subtypes;
    return $subtypes;
}

/**
 * Given a content type and a subtype id, return the information about that
 * content subtype.
 *
 * @param $type
 *   The content type being fetched.
 * @param $subtype_id
 *   The id of the subtype being fetched.
 *
 * @return
 *   An array of information describing the content subtype.
 */
function ctools_content_get_subtype($type, $subtype_id) {
    $subtype = array();
    if (is_array($type)) {
        $plugin = $type;
    }
    else {
        $plugin = ctools_get_content_type($type);
    }
    $function = ctools_plugin_get_function($plugin, 'content type');
    if ($function) {
        $subtype = $function($subtype_id, $plugin);
    }
    else {
        $subtypes = ctools_content_get_subtypes($type);
        if (isset($subtypes[$subtype_id])) {
            $subtype = $subtypes[$subtype_id];
        }
        // If there's only 1 and we somehow have the wrong subtype ID, do not
        // care. Return the proper subtype anyway.
        if (empty($subtype) && !empty($plugin['single'])) {
            $subtype = current($subtypes);
        }
    }
    if ($subtype) {
        // Ensure that the 'subtype_id' value exists. This is also done in
        // ctools_content_get_subtypes(), but it wouldn't be called if the plugin
        // provides the subtype through its own function.
        if (!isset($subtype['subtype_id'])) {
            $subtype['subtype_id'] = $subtype_id;
        }
        ctools_content_prepare_subtype($subtype, $plugin);
    }
    return $subtype;
}

/**
 * Ensure minimal required settings on a content subtype exist.
 */
function ctools_content_prepare_subtype(&$subtype, $plugin) {
    foreach (array(
        'path',
        'js',
        'css',
    ) as $key) {
        if (!isset($subtype[$key]) && isset($plugin[$key])) {
            $subtype[$key] = $plugin[$key];
        }
    }
    // Trigger hook_ctools_content_subtype_alter().
    drupal_alter('ctools_content_subtype', $subtype, $plugin);
}

/**
 * Get the content from a given content type.
 *
 * @param $type
 *   The content type. May be the name or an already loaded content type plugin.
 * @param $subtype
 *   The name of the subtype being rendered.
 * @param $conf
 *   The configuration for the content type.
 * @param $keywords
 *   An array of replacement keywords that come from outside contexts.
 * @param $args
 *   The arguments provided to the owner of the content type. Some content may
 *   wish to configure itself based on the arguments the panel or dashboard
 *   received.
 * @param $context
 *   An array of context objects available for use.
 * @param $incoming_content
 *   Any incoming content, if this display is a wrapper.
 *
 * @return
 *   The content as rendered by the plugin, or NULL.
 *   This content should be an object with the following possible properties:
 *   - title: The safe to render title of the content.
 *   - title_heading: The title heading.
 *   - content: The safe to render HTML content.
 *   - links: An array of links associated with the content suitable for
 *     theme('links').
 *   - more: An optional 'more' link (destination only)
 *   - admin_links: Administrative links associated with the content, suitable
 *     for theme('links').
 *   - feeds: An array of feed icons or links associated with the content.
 *     Each member of the array is rendered HTML.
 *   - type: The content type.
 *   - subtype: The content subtype. These two may be used together as
 *     module-delta for block style rendering.
 */
function ctools_content_render($type, $subtype, $conf, $keywords = array(), $args = array(), $context = array(), $incoming_content = '') {
    if (is_array($type)) {
        $plugin = $type;
    }
    else {
        $plugin = ctools_get_content_type($type);
    }
    $subtype_info = ctools_content_get_subtype($plugin, $subtype);
    $function = ctools_plugin_get_function($subtype_info, 'render callback');
    if (!$function) {
        $function = ctools_plugin_get_function($plugin, 'render callback');
    }
    if ($function) {
        $pane_context = ctools_content_select_context($plugin, $subtype, $conf, $context);
        if ($pane_context === FALSE) {
            return;
        }
        $content = $function($subtype, $conf, $args, $pane_context, $incoming_content);
        if (empty($content)) {
            return;
        }
        // Set up some defaults and other massaging on the content before we hand
        // it back to the caller.
        if (!isset($content->type)) {
            $content->type = $plugin['name'];
        }
        if (!isset($content->subtype)) {
            $content->subtype = $subtype;
        }
        // Override the title if configured to.
        if (!empty($conf['override_title'])) {
            // Give previous title as an available substitution here.
            $keywords['%title'] = empty($content->title) ? '' : $content->title;
            $content->original_title = $keywords['%title'];
            $content->title = $conf['override_title_text'];
            $content->title_heading = isset($conf['override_title_heading']) ? $conf['override_title_heading'] : 'h2';
        }
        if (!empty($content->title)) {
            // Perform substitutions.
            if (!empty($keywords) || !empty($context)) {
                $content->title = ctools_context_keyword_substitute($content->title, $keywords, $context);
            }
            // Sterilize the title.
            $content->title = filter_xss_admin($content->title);
            // If a link is specified, populate.
            if (!empty($content->title_link)) {
                if (!is_array($content->title_link)) {
                    $url = array(
                        'href' => $content->title_link,
                    );
                }
                else {
                    $url = $content->title_link;
                }
                // Set defaults so we don't bring up notices.
                $url += array(
                    'href' => '',
                    'attributes' => array(),
                    'query' => array(),
                    'fragment' => '',
                    'absolute' => NULL,
                    'html' => TRUE,
                );
                $content->title = l($content->title, $url['href'], $url);
            }
        }
        return $content;
    }
}

/**
 * Determine if a content type can be edited or not.
 *
 * Some content types simply have their content and no options. This function
 * lets a UI determine if it should display an edit link or not.
 */
function ctools_content_editable($type, $subtype, $conf) {
    if (empty($type['edit form']) && empty($subtype['edit form'])) {
        return FALSE;
    }
    $function = FALSE;
    if (!empty($subtype['check editable'])) {
        $function = ctools_plugin_get_function($subtype, 'check editable');
    }
    elseif (!empty($type['check editable'])) {
        $function = ctools_plugin_get_function($type, 'check editable');
    }
    if ($function) {
        return $function($type, $subtype, $conf);
    }
    return TRUE;
}

/**
 * Get the administrative title from a given content type.
 *
 * @param $type
 *   The content type. May be the name or an already loaded content type object.
 * @param $subtype
 *   The subtype being rendered.
 * @param $conf
 *   The configuration for the content type.
 * @param $context
 *   An array of context objects available for use. These may be placeholders.
 */
function ctools_content_admin_title($type, $subtype, $conf, $context = NULL) {
    if (is_array($type)) {
        $plugin = $type;
    }
    elseif (is_string($type)) {
        $plugin = ctools_get_content_type($type);
    }
    else {
        return;
    }
    if ($function = ctools_plugin_get_function($plugin, 'admin title')) {
        $pane_context = ctools_content_select_context($plugin, $subtype, $conf, $context);
        if ($pane_context === FALSE) {
            if ($plugin['name'] == $subtype) {
                return t('@type will not display due to missing context', array(
                    '@type' => $plugin['name'],
                ));
            }
            return t('@type:@subtype will not display due to missing context', array(
                '@type' => $plugin['name'],
                '@subtype' => $subtype,
            ));
        }
        return $function($subtype, $conf, $pane_context);
    }
    elseif (isset($plugin['admin title'])) {
        return $plugin['admin title'];
    }
    elseif (isset($plugin['title'])) {
        return $plugin['title'];
    }
}

/**
 * Get the proper icon path to use, falling back to default icons if no icon exists.
 *
 * $subtype
 *   The loaded subtype info.
 */
function ctools_content_admin_icon($subtype) {
    $icon = '';
    if (isset($subtype['icon'])) {
        $icon = $subtype['icon'];
        if (!file_exists($icon)) {
            $icon = $subtype['path'] . '/' . $icon;
        }
    }
    if (empty($icon) || !file_exists($icon)) {
        $icon = ctools_image_path('no-icon.png');
    }
    return $icon;
}

/**
 * Set up the default $conf for a new instance of a content type.
 */
function ctools_content_get_defaults($plugin, $subtype) {
    if (isset($plugin['defaults'])) {
        $defaults = $plugin['defaults'];
    }
    elseif (isset($subtype['defaults'])) {
        $defaults = $subtype['defaults'];
    }
    if (isset($defaults)) {
        if (is_string($defaults) && function_exists($defaults)) {
            if ($return = $defaults($pane)) {
                return $return;
            }
        }
        elseif (is_array($defaults)) {
            return $defaults;
        }
    }
    return array();
}

/**
 * Get the administrative title from a given content type.
 *
 * @param $type
 *   The content type. May be the name or an already loaded content type object.
 * @param $subtype
 *   The subtype being rendered.
 * @param $conf
 *   The configuration for the content type.
 * @param $context
 *   An array of context objects available for use. These may be placeholders.
 */
function ctools_content_admin_info($type, $subtype, $conf, $context = NULL) {
    if (is_array($type)) {
        $plugin = $type;
    }
    else {
        $plugin = ctools_get_content_type($type);
    }
    if ($function = ctools_plugin_get_function($plugin, 'admin info')) {
        $output = $function($subtype, $conf, $context);
    }
    if (empty($output) || !is_object($output)) {
        $output = new stdClass();
        // Replace the _ with " " for a better output.
        $subtype = check_plain(str_replace("_", " ", $subtype));
        $output->title = $subtype;
        $output->content = t('No info available.');
    }
    return $output;
}

/**
 * Add the default FAPI elements to the content type configuration form.
 */
function ctools_content_configure_form_defaults($form, &$form_state) {
    $plugin = $form_state['plugin'];
    $subtype = $form_state['subtype'];
    $contexts = isset($form_state['contexts']) ? $form_state['contexts'] : NULL;
    $conf = $form_state['conf'];
    $add_submit = FALSE;
    if (!empty($subtype['required context']) && is_array($contexts)) {
        $form['context'] = ctools_context_selector($contexts, $subtype['required context'], isset($conf['context']) ? $conf['context'] : array());
        $add_submit = TRUE;
    }
    ctools_include('dependent');
    // Unless we're not allowed to override the title on this content type, add this
    // gadget to all panes.
    if (empty($plugin['no title override']) && empty($subtype['no title override'])) {
        $form['aligner_start'] = array(
            '#markup' => '<div class="option-text-aligner clearfix">',
        );
        $form['override_title'] = array(
            '#type' => 'checkbox',
            '#default_value' => isset($conf['override_title']) ? $conf['override_title'] : '',
            '#title' => t('Override title'),
            '#id' => 'override-title-checkbox',
        );
        $form['override_title_text'] = array(
            '#type' => 'textfield',
            '#default_value' => isset($conf['override_title_text']) ? $conf['override_title_text'] : '',
            '#size' => 35,
            '#id' => 'override-title-textfield',
            '#dependency' => array(
                'override-title-checkbox' => array(
                    1,
                ),
            ),
            '#dependency_type' => 'hidden',
        );
        $form['override_title_heading'] = array(
            '#type' => 'select',
            '#default_value' => isset($conf['override_title_heading']) ? $conf['override_title_heading'] : 'h2',
            '#options' => array(
                'h1' => t('h1'),
                'h2' => t('h2'),
                'h3' => t('h3'),
                'h4' => t('h4'),
                'h5' => t('h5'),
                'h6' => t('h6'),
                'div' => t('div'),
                'span' => t('span'),
            ),
            '#id' => 'override-title-heading',
            '#dependency' => array(
                'override-title-checkbox' => array(
                    1,
                ),
            ),
            '#dependency_type' => 'hidden',
        );
        $form['aligner_stop'] = array(
            '#markup' => '</div>',
        );
        if (is_array($contexts)) {
            $form['override_title_markup'] = array(
                '#prefix' => '<div class="description">',
                '#suffix' => '</div>',
                '#markup' => t('You may use %keywords from contexts, as well as %title to contain the original title.'),
            );
        }
        $add_submit = TRUE;
    }
    if ($add_submit) {
        // '#submit' is already set up due to the wizard.
        $form['#submit'][] = 'ctools_content_configure_form_defaults_submit';
    }
    return $form;
}

/**
 * Submit handler to store context/title override info.
 */
function ctools_content_configure_form_defaults_submit(&$form, &$form_state) {
    if (isset($form_state['values']['context'])) {
        $form_state['conf']['context'] = $form_state['values']['context'];
    }
    if (isset($form_state['values']['override_title'])) {
        $form_state['conf']['override_title'] = $form_state['values']['override_title'];
        $form_state['conf']['override_title_text'] = $form_state['values']['override_title_text'];
        $form_state['conf']['override_title_heading'] = $form_state['values']['override_title_heading'];
    }
}

/**
 * Get the config form.
 *
 * The $form_info and $form_state need to be preconfigured with data you'll need
 * such as whether or not you're using ajax, or the modal. $form_info will need
 * your next/submit callbacks so that you can cache your data appropriately.
 *
 * @return
 *   If this function returns false, no form exists.
 */
function ctools_content_form($op, $form_info, &$form_state, $plugin, $subtype_name, $subtype, &$conf, $step = NULL) {
    $form_state += array(
        'plugin' => $plugin,
        'subtype' => $subtype,
        'subtype_name' => $subtype_name,
        'conf' => &$conf,
        'op' => $op,
    );
    $form_info += array(
        'id' => 'ctools_content_form',
        'show back' => TRUE,
    );
    // Turn the forms defined in the plugin into the format the wizard needs.
    if ($op == 'add') {
        if (!empty($subtype['add form'])) {
            _ctools_content_create_form_info($form_info, $subtype['add form'], $subtype, $subtype, $op);
        }
        elseif (!empty($plugin['add form'])) {
            _ctools_content_create_form_info($form_info, $plugin['add form'], $plugin, $subtype, $op);
        }
    }
    if (empty($form_info['order'])) {
        // Use the edit form for the add form if add form was completely left off.
        if (!empty($subtype['edit form'])) {
            _ctools_content_create_form_info($form_info, $subtype['edit form'], $subtype, $subtype, $op);
        }
        elseif (!empty($plugin['edit form'])) {
            _ctools_content_create_form_info($form_info, $plugin['edit form'], $plugin, $subtype, $op);
        }
    }
    if (empty($form_info['order'])) {
        return FALSE;
    }
    ctools_include('wizard');
    return ctools_wizard_multistep_form($form_info, $step, $form_state);
}
function _ctools_content_create_form_info(&$form_info, $info, $plugin, $subtype, $op) {
    if (is_string($info)) {
        if (empty($subtype['title'])) {
            $title = t('Configure');
        }
        elseif ($op == 'add') {
            $title = t('Configure new !subtype_title', array(
                '!subtype_title' => $subtype['title'],
            ));
        }
        else {
            $title = t('Configure !subtype_title', array(
                '!subtype_title' => $subtype['title'],
            ));
        }
        $form_info['order'] = array(
            'form' => $title,
        );
        $form_info['forms'] = array(
            'form' => array(
                'title' => $title,
                'form id' => $info,
                'wrapper' => 'ctools_content_configure_form_defaults',
            ),
        );
    }
    elseif (is_array($info)) {
        $form_info['order'] = array();
        $form_info['forms'] = array();
        $count = 0;
        $base = 'step';
        $wrapper = NULL;
        foreach ($info as $form_id => $title) {
            // @todo -- docs say %title can be used to sub for the admin title.
            $step = $base . ++$count;
            if (empty($wrapper)) {
                $wrapper = $step;
            }
            if (is_array($title)) {
                if (!empty($title['default'])) {
                    $wrapper = $step;
                }
                $title = $title['title'];
            }
            $form_info['order'][$step] = $title;
            $form_info['forms'][$step] = array(
                'title' => $title,
                'form id' => $form_id,
            );
        }
        if ($wrapper) {
            $form_info['forms'][$wrapper]['wrapper'] = 'ctools_content_configure_form_defaults';
        }
    }
}

/**
 * Get an array of all available content types that can be fed into the
 * display editor for the add content list.
 *
 * @param $context
 *   If a context is provided, content that requires that context can apepar.
 * @param $has_content
 *   Whether or not the display will have incoming content
 * @param $allowed_types
 *   An array of allowed content types (pane types) keyed by content_type . '-' . sub_type
 * @param $default_types
 *   A default allowed/denied status for content that isn't known about
 */
function ctools_content_get_available_types($contexts = NULL, $has_content = FALSE, $allowed_types = NULL, $default_types = NULL) {
    $plugins = ctools_get_content_types();
    $available = array();
    foreach ($plugins as $id => $plugin) {
        foreach (ctools_content_get_subtypes($plugin) as $subtype_id => $subtype) {
            // Exclude items that require content if we're saying we don't
            // provide it.
            if (!empty($subtype['requires content']) && !$has_content) {
                continue;
            }
            // Check to see if the content type can be used in this context.
            if (!empty($subtype['required context'])) {
                if (!ctools_context_match_requirements($contexts, $subtype['required context'])) {
                    continue;
                }
            }
            // Check to see if the passed-in allowed types allows this content.
            if ($allowed_types) {
                $key = $id . '-' . $subtype_id;
                if (!isset($allowed_types[$key])) {
                    $allowed_types[$key] = isset($default_types[$id]) ? $default_types[$id] : $default_types['other'];
                }
                if (!$allowed_types[$key]) {
                    continue;
                }
            }
            // Check if the content type provides an access callback.
            if (isset($subtype['create content access']) && function_exists($subtype['create content access']) && !$subtype['create content access']($plugin, $subtype)) {
                continue;
            }
            // If we made it through all the tests, then we can use this content.
            $available[$id][$subtype_id] = $subtype;
        }
    }
    return $available;
}

/**
 * Get an array of all content types that can be fed into the
 * display editor for the add content list, regardless of
 * availability.
 */
function ctools_content_get_all_types() {
    $plugins = ctools_get_content_types();
    $available = array();
    foreach ($plugins as $id => $plugin) {
        foreach (ctools_content_get_subtypes($plugin) as $subtype_id => $subtype) {
            // If we made it through all the tests, then we can use this content.
            $available[$id][$subtype_id] = $subtype;
        }
    }
    return $available;
}

/**
 * Select the context to be used for a piece of content, based upon config.
 *
 * @param $plugin
 *   The content plugin
 * @param $subtype
 *   The subtype of the content.
 * @param $conf
 *   The configuration array that should contain the context.
 * @param $contexts
 *   A keyed array of available contexts.
 *
 * @return
 *   The matching contexts or NULL if none or necessary, or FALSE if
 *   requirements can't be met.
 */
function ctools_content_select_context($plugin, $subtype, $conf, $contexts) {
    // Identify which of our possible contexts apply.
    if (empty($subtype)) {
        return;
    }
    $subtype_info = ctools_content_get_subtype($plugin, $subtype);
    if (empty($subtype_info)) {
        return;
    }
    if (!empty($subtype_info['all contexts']) || !empty($plugin['all contexts'])) {
        return $contexts;
    }
    // If the content requires a context, fetch it; if no context is returned,
    // do not display the pane.
    if (empty($subtype_info['required context'])) {
        return;
    }
    // Deal with dynamic required contexts not getting updated in the panes.
    // For example, Views let you dynamically change context info. While
    // we cannot be perfect, one thing we can do is if no context at all
    // was asked for, and then was later added but none is selected, make
    // a best guess as to what context should be used. THis is right more
    // than it's wrong.
    if (is_array($subtype_info['required context'])) {
        if (empty($conf['context']) || count($subtype_info['required context']) != count($conf['context'])) {
            foreach ($subtype_info['required context'] as $index => $required) {
                if (!isset($conf['context'][$index])) {
                    $filtered = ctools_context_filter($contexts, $required);
                    if ($filtered) {
                        $keys = array_keys($filtered);
                        $conf['context'][$index] = array_shift($keys);
                    }
                }
            }
        }
    }
    else {
        if (empty($conf['context'])) {
            $filtered = ctools_context_filter($contexts, $subtype_info['required context']);
            if ($filtered) {
                $keys = array_keys($filtered);
                $conf['context'] = array_shift($keys);
            }
        }
    }
    if (empty($conf['context'])) {
        return;
    }
    $context = ctools_context_select($contexts, $subtype_info['required context'], $conf['context']);
    return $context;
}

/**
 * Fetch a piece of content from the addressable content system.
 *
 * @param $address
 *   A string or an array representing the address of the content.
 * @param $type
 *   The type of content to return. The type is dependent on what
 *   the content actually is. The default, 'content' means a simple
 *   string representing the content. However, richer systems may
 *   offer more options. For example, Panels might allow the
 *   fetching of 'display' and 'pane' objects. Page Manager
 *   might allow for the fetching of 'task_handler' objects
 *   (AKA variants).
 */
function ctools_get_addressable_content($address, $type = 'content') {
    if (!is_array($address)) {
        $address = explode('::', $address);
    }
    if (!$address) {
        return;
    }
    // This removes the module from the address so the
    // implementor is not responsible for that part.
    $module = array_shift($address);
    return module_invoke($module, 'addressable_content', $address, $type);
}