MDL-56958 ajax: Prefer the general renderer

Author: Damyon Wiese

lib/ajax/service.php

@@ -32,6 +32,8 @@
 require_once(__DIR__ . '/../../config.php');
 require_once($CFG->libdir . '/externallib.php');
 
+define('PREFERRED_RENDERER_TARGET', RENDERER_TARGET_GENERAL);
+
 $rawjson = file_get_contents('php://input');
 
 $requests = json_decode($rawjson, true);

lib/outputfactories.php

@@ -137,7 +137,9 @@ protected function get_target_suffix($target) {
             // If the target hasn't been specified we need to guess the defaults.
             // We also override the target with the default if the maintenance target has been provided.
             // This ensures we don't use the maintenance renderer if we are processing a special target.
-            if (CLI_SCRIPT) {
+            if (defined('PREFERRED_RENDERER_TARGET')) {
+                $target = PREFERRED_RENDERER_TARGET;
+            } else if (CLI_SCRIPT) {
                 $target = RENDERER_TARGET_CLI;
             } else if (AJAX_SCRIPT) {
                 $target = RENDERER_TARGET_AJAX;