MDL-71686 forms: allow arrays in dynamic forms args

lib/form/amd/src/dynamicform.js

@@ -136,9 +136,15 @@ export default class DynamicForm {
      * @public
      */
     load(args = null) {
-        const formData = new URLSearchParams(Object.entries(args || {}));
+        const serialize = function(obj, prefix = '') {
+            return [].concat(...Object.entries(obj).map(([idx, v]) => {
+                const k = prefix ? prefix + "[" + idx + "]" : idx;
+                return (typeof v === "object") ? serialize(v, k) : `${k}=${encodeURIComponent(v)}`;
+            })).join("&");
+        };
+        const formData = serialize(args || {});
         const pendingPromise = new Pending('core_form/dynamicform:load');
-        return this.getBody(formData.toString())
+        return this.getBody(formData)
         .then((resp) => this.updateForm(resp))
         .then(pendingPromise.resolve);
     }

lib/form/amd/src/modalform.js

@@ -115,6 +115,13 @@ export default class ModalForm {
      */
     show() {
         const pendingPromise = new Pending('core_form/modalform:init');
+        const serialize = function(obj, prefix = '') {
+            return [].concat(...Object.entries(obj).map(([idx, v]) => {
+                const k = prefix ? prefix + "[" + idx + "]" : idx;
+                return (typeof v === "object") ? serialize(v, k) : `${k}=${encodeURIComponent(v)}`;
+            })).join("&");
+        };
+
         return ModalFactory.create(this.config.modalConfig)
         .then((modal) => {
             this.modal = modal;
@@ -122,8 +129,8 @@ export default class ModalForm {
             // Retrieve the form and set the modal body. We can not set the body in the modalConfig,
             // we need to make sure that the modal already exists when we render the form. Some form elements
             // such as date_selector inspect the existing elements on the page to find the highest z-index.
-            const formParams = new URLSearchParams(Object.entries(this.config.args || {}));
-            const bodyContent = this.getBody(formParams.toString());
+            const formParams = serialize(this.config.args || {});
+            const bodyContent = this.getBody(formParams);
             this.modal.setBodyContent(bodyContent);
             bodyContent.catch(Notification.exception);