prevent creation of filter rules matching no feeds

classes/pref/filters.php

@@ -695,7 +695,7 @@ class Pref_Filters extends Handler_Protected {
 		$feed_ids = explode(",", clean($_REQUEST["ids"]));
 
 		print json_encode([
-			"multiselect" => $this->_feed_multi_select("feed_id", $feed_ids, 'style="width : 540px; height : 300px" dojoType="dijit.form.MultiSelect"')
+			"multiselect" => $this->_feed_multi_select("feed_id", $feed_ids, 'required="1" style="width : 540px; height : 300px" dojoType="fox.form.ValidationMultiSelect"')
 		]);
 	}
 

js/form/ValidationMultiSelect.js

@@ -0,0 +1,20 @@
+/* global define */
+
+// only supports required for the time being
+// TODO: maybe show dojo native error message? i dunno
+define(["dojo/_base/declare", "dojo/_base/lang", "dijit/form/MultiSelect", ],
+    function(declare, lang, MultiSelect) {
+
+        return declare('fox.form.ValidationMultiSelect', [MultiSelect], {
+            constructor: function(params){
+                this.constraints = {};
+                this.baseClass += ' dijitValidationMultiSelect';
+            },
+            validate: function(/*Boolean*/ isFocused){
+                if (this.required && this.attr('value').length == 0)
+                    return false;
+
+                return true;
+            },
+        })
+    });

js/prefs.js

@@ -53,6 +53,7 @@ require(["dojo/_base/kernel",
 	"fox/PrefLabelTree",
 	"fox/Toolbar",
 	"fox/SingleUseDialog",
+	"fox/form/ValidationMultiSelect",
 	"fox/form/ValidationTextArea",
 	"fox/form/Select",
 	"fox/form/ComboButton",

js/tt-rss.js

@@ -51,6 +51,7 @@ require(["dojo/_base/kernel",
 	"fox/FeedTree",
 	"fox/Toolbar",
 	"fox/SingleUseDialog",
+	"fox/form/ValidationMultiSelect",
 	"fox/form/ValidationTextArea",
 	"fox/form/Select",
 	"fox/form/ComboButton",