From 810afdaf5a429468d31b09ae5a7f995dd11568f8 Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <noreply@fakecake.org>
Date: Sun, 21 Feb 2021 12:28:25 +0300
Subject: [PATCH] prevent creation of filter rules matching no feeds

---
 classes/pref/filters.php         |  2 +-
 js/form/ValidationMultiSelect.js | 20 ++++++++++++++++++++
 js/prefs.js                      |  1 +
 js/tt-rss.js                     |  1 +
 4 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 js/form/ValidationMultiSelect.js

diff --git a/classes/pref/filters.php b/classes/pref/filters.php
index c00e52bde..9388cc8d7 100755
--- a/classes/pref/filters.php
+++ b/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"')
 		]);
 	}
 
diff --git a/js/form/ValidationMultiSelect.js b/js/form/ValidationMultiSelect.js
new file mode 100644
index 000000000..4e7263c61
--- /dev/null
+++ b/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;
+            },
+        })
+    });
diff --git a/js/prefs.js b/js/prefs.js
index a23a74856..8f4f45700 100755
--- a/js/prefs.js
+++ b/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",
diff --git a/js/tt-rss.js b/js/tt-rss.js
index 8d7dd00a6..4a7f2e643 100644
--- a/js/tt-rss.js
+++ b/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",