Added better visual feedback on required languages

In settings panel. This, again, is a port of code from multilingual text box.

Fixes #5

assets/multilingual_upload_field.settings.js

@@ -0,0 +1,55 @@
+(function ($, undefined) {
+
+	'use strict';
+
+	if (!!Symphony.Extensions.MultilingualUploadField) {
+		return;
+	}
+	Symphony.Extensions.MultilingualUploadField = true;
+
+	// from backend.views.js
+	var change = function (e) {
+		var selectbox = $(this);
+		var parent = selectbox.parents('.instance');
+		var headline = parent.find('.frame-header h4');
+		var values = selectbox.find(':selected');
+		var span = headline.find('.required');
+
+		if(!!values.length) {
+			var langs = [];
+			values.each(function (index, elem) {
+				var text = $(this).text();
+				langs.push(text.split(' ||')[0]);
+				if (index < values.length - 2) {
+					langs.push(', ');
+				} else if (index < values.length - 1) {
+					langs.push(' and ');
+				}
+			});
+
+			if (!span.length) {
+				span = $('<span />', {
+					class: 'required'
+				}).appendTo(headline);
+			}
+
+			span.text(
+				'— ' + langs.join('') + ' ' +
+				Symphony.Language.get(langs.length > 1 ? 'are' : 'is') + ' ' +
+				Symphony.Language.get('required')
+			);
+		}
+
+		// Is not required
+		else {
+			headline.find('.required').remove();
+		}
+	};
+
+	$(function () {
+		$('.field-multilingual_upload.instance select[name*="[required_languages]"]')
+			.on('change', change)
+			.trigger('change');
+	});
+
+})(jQuery);

extension.driver.php

@@ -14,6 +14,7 @@ class Extension_Multilingual_Upload_Field extends Extension
 		const FIELD_TABLE = 'tbl_fields_multilingual_upload';
 
 		protected static $assets_loaded = false;
+		protected static $assets_settings_loaded = false;
 
 		/*------------------------------------------------------------------------------------------------*/
 		/*  Installation  */
@@ -220,4 +221,18 @@ public static function appendAssets(){
 				$page->addScriptToHead(URL.'/extensions/'.MUF_GROUP.'/assets/'.MUF_GROUP.'.publish.js', null, false);
 			}
 		}
+
+		public static function appendSettingsAssets(){
+			if( self::$assets_settings_loaded === false
+				&& class_exists('Administration')
+				&& Administration::instance() instanceof Administration
+				&& Administration::instance()->Page instanceof HTMLPage ){
+
+				self::$assets_settings_loaded = true;
+
+				$page = Administration::instance()->Page;
+
+				$page->addScriptToHead(URL.'/extensions/'.MUF_GROUP.'/assets/'.MUF_GROUP.'.settings.js', null, false);
+			}
+		}
 	}

fields/field.multilingual_upload.php

@@ -85,6 +85,8 @@ public function get($field = null)
 
 		public function displaySettingsPanel(XMLElement &$wrapper, $errors = null)
 		{
+			Extension_Multilingual_Upload_Field::appendSettingsAssets();
+
 			parent::displaySettingsPanel($wrapper, $errors);
 
 			$last_div_pos = $wrapper->getNumberOfChildren() - 1;