function advagg_add_preload_header

Add in the preload header for CSS and JS external files.

Paramètres

string $url: The url of the external host.

Return value

bool TRUE if it was added to the head.

2 calls to advagg_add_preload_header()

advagg_add_resource_hints_array dans ./advagg.module

Find dns_prefetch and call advagg_add_dns_prefetch().

_advagg_process_html dans ./advagg.module

Replacement for template_process_html().

Fichier

./advagg.module, line 6468

Code

function advagg_add_preload_header($url = '', $as = '') {
    // Get defaults and setup static's.
    $list =& drupal_static(__FUNCTION__ . ':list', array());
    $output =& drupal_static(__FUNCTION__ . ':output');
    $header_strlen =& drupal_static(__FUNCTION__ . ':strlen', 0);
    static $resource_hints_preload_order;
    if (!isset($resource_hints_preload_order)) {
        $resource_hints_preload_order = advagg_get_resource_hints_preload_settings();
    }
    if (!isset($output)) {
        $keys = array_keys($resource_hints_preload_order);
        $output = array_fill_keys($keys, array());
    }
    // Output headers.
    if (empty($url)) {
        // Call hook_advagg_preload_header_alter()
        drupal_alter('advagg_preload_header', $output);
        // Build header string.
        $header_value = '';
        foreach ($output as $value) {
            if (!empty($value)) {
                // Remove empty values.
                $value = array_filter($value);
                foreach ($value as $string) {
                    $header_strlen += strlen($string) + 2;
                    // Don't add if over the limit.
                    if ($header_strlen >= variable_get('advagg_resource_hints_preload_max_size', ADVAGG_RESOURCE_HINTS_PRELOAD_MAX_SIZE)) {
                        continue;
                    }
                    // Add to $header_value string.
                    if (empty($header_value)) {
                        $header_value = $string;
                    }
                    else {
                        $header_value .= ',' . $string;
                    }
                }
            }
        }
        if (!empty($header_value)) {
            drupal_add_http_header('Link', $header_value, TRUE);
        }
        return FALSE;
    }
    // Check for duplicates.
    if (isset($list[$url])) {
        return FALSE;
    }
    // Fill in missing info.
    $payload = "<{$url}>; rel=preload";
    list($as, $type, $crossorigin, $parse) = advagg_get_preload_info_from_url($url, $as);
    if (!empty($as) && $as === 'php') {
        $list[$url] = FALSE;
        return FALSE;
    }
    $additional_info = array();
    if (!empty($crossorigin)) {
        $additional_info[] = "crossorigin";
    }
    if (!empty($type)) {
        if ($type !== 'text/css' || $type !== 'text/javascript' || $as !== 'image') {
            // Type is not needed for css/js files and images.
            $additional_info[] = "type=\"{$type}\"";
        }
    }
    $additional_info = implode('; ', $additional_info);
    // Get settings.
    if (!empty($as) && !empty($resource_hints_preload_order[$as])) {
        $settings = $resource_hints_preload_order[$as];
    }
    elseif (!empty($resource_hints_preload_order['all_others'])) {
        $settings = $resource_hints_preload_order['all_others'];
    }
    // Apply settings.
    if (!$settings['enabled']) {
        $list[$url] = FALSE;
        return FALSE;
    }
    if (!$settings['local'] && empty($parse['host'])) {
        $list[$url] = FALSE;
        return FALSE;
    }
    if (!$settings['external'] && !empty($parse['host'])) {
        $list[$url] = FALSE;
        return FALSE;
    }
    // Add additional info and queue.
    if (!empty($as)) {
        $payload .= "; as={$as}";
    }
    if (!empty($additional_info)) {
        $payload .= "; {$additional_info}";
    }
    if (!$settings['push']) {
        $payload .= "; nopush";
    }
    $list[$url] = TRUE;
    $output[$as][] = $payload;
}