function _block_get_cache_id

Assemble the cache_id to use for a given block.

The cache_id string reflects the viewing context for the current block instance, obtained by concatenating the relevant context information (user, page, ...) according to the block's cache settings (BLOCK_CACHE_* constants). Two block instances can use the same cached content when they share the same cache_id.

Theme and language contexts are automatically differentiated.

Parameters

$block: The block to get the cache_id from.

Return value

The string used as cache_id for the block.

File

modules/block/block.module, line 966

Code

function _block_get_cache_id($block) {
    global $user;
    // User 1 being out of the regular 'roles define permissions' schema,
    // it brings too many chances of having unwanted output get in the cache
    // and later be served to other users. We therefore exclude user 1 from
    // block caching.
    if (variable_get('block_cache', FALSE) && !in_array($block->cache, array(
        DRUPAL_NO_CACHE,
        DRUPAL_CACHE_CUSTOM,
    )) && $user->uid != 1) {
        // Start with common sub-patterns: block identification, theme, language.
        $cid_parts[] = $block->module;
        $cid_parts[] = $block->delta;
        drupal_alter('block_cid_parts', $cid_parts, $block);
        $cid_parts = array_merge($cid_parts, drupal_render_cid_parts($block->cache));
        return implode(':', $cid_parts);
    }
}