Fix #773 allow filepicker work inside lists, respond to mutation event

CHANGELOG.md

@@ -5,6 +5,7 @@
     * Fix [#1034](https://github.com/getgrav/grav/issues/1034) redirect of page creation procedure when system.home.hide_in_urls is enabled
     * Media (Page): Do not extend parent metehod for sending files since Safari and IE API for FormData don’t implement `delete` ([#772](https://github.com/getgrav/grav-plugin-admin/issues/772))
     * Clean up POST keys containing square brackets, allows for regex ranges in routes ([#776](https://github.com/getgrav/grav-plugin-admin/issues/776))
+    * Fix [#773](https://github.com/getgrav/grav-plugin-admin/issues/773) allow filepicker work inside lists, respond to mutation event
 
 # v1.2.2
 ## 09/08/2016

themes/grav/app/forms/fields/filepicker.js

@@ -5,11 +5,29 @@ import request from '../../utils/request';
 export default class FilePickerField {
 
     constructor(options) {
-        $('[data-grav-filepicker]').each((index, element) => this.add(element));
+        this.items = $();
+        this.options = Object.assign({}, this.defaults, options);
+
+        $('[data-grav-filepicker]').each((index, element) => this.addItem(element));
+        $('body').on('mutation._grav', this._onAddedNodes.bind(this));
     }
 
-    add(element) {
+    _onAddedNodes(event, target/* , record, instance */) {
+        let fields = $(target).find('[data-grav-filepicker]');
+        if (!fields.length) { return; }
+
+        fields.each((index, field) => {
+            field = $(field);
+            if (!~this.items.index(field)) {
+                this.addItem(field);
+            }
+        });
+    }
+
+    addItem(element) {
         element = $(element);
+        this.items = this.items.add(element);
+
         let tag = element.prop('tagName').toLowerCase();
         let isInput = tag === 'input' || tag === 'select';