diff --git a/classes/pref/feeds.php b/classes/pref/feeds.php
index f337d7f4e..2649d58a1 100755
--- a/classes/pref/feeds.php
+++ b/classes/pref/feeds.php
@@ -1557,52 +1557,10 @@ class Pref_Feeds extends Handler_Protected {
 	}
 
 	function batchSubscribe() {
-		print "<form onsubmit='return false'>";
-
-		print_hidden("op", "pref-feeds");
-		print_hidden("method", "batchaddfeeds");
-
-		print "<header class='horizontal'>".__("One valid feed per line (no detection is done)")."</header>";
-		print "<section>";
-
-		print "<textarea
-			style='font-size : 12px; width : 98%; height: 200px;'
-			dojoType='fox.form.ValidationTextArea' required='1' name='feeds'></textarea>";
-
-		if (get_pref('ENABLE_FEED_CATS')) {
-			print "<fieldset>";
-			print "<label>" . __('Place in category:') . "</label> ";
-			print_feed_cat_select("cat", false, 'dojoType="fox.form.Select"');
-			print "</fieldset>";
-		}
-
-		print "</section>";
-
-		print "<div id='feedDlg_loginContainer' style='display : none'>";
-
-		print "<header>" . __("Authentication") . "</header>";
-		print "<section>";
-
-		print "<input dojoType='dijit.form.TextBox' name='login' placeHolder=\"".__("Login")."\">
-			<input placeHolder=\"".__("Password")."\" dojoType=\"dijit.form.TextBox\" type='password'
-				autocomplete='new-password' name='pass''></div>";
-
-		print "</section>";
-		print "</div>";
-
-		print "<fieldset class='narrow'>
-			<label class='checkbox'><input type='checkbox' name='need_auth' dojoType='dijit.form.CheckBox'
-					onclick='App.displayIfChecked(this, \"feedDlg_loginContainer\")'> ".
-				__('Feeds require authentication.')."</label></div>";
-		print "</fieldset>";
-
-		print "<footer>
-			<button dojoType='dijit.form.Button' onclick='App.dialogOf(this).execute()' type='submit' class='alt-primary'>".
-				__('Subscribe')."</button>
-			<button dojoType='dijit.form.Button' onclick='App.dialogOf(this).hide()'>".__('Cancel')."</button>
-			</footer>";
-
-		print "</form>";
+		print json_encode([
+			"enable_cats" => (int)get_pref('ENABLE_FEED_CATS'),
+			"cat_select" => format_feed_cat_select("cat", false, 'dojoType="fox.form.Select"')
+		]);
 	}
 
 	function batchAddFeeds() {
diff --git a/include/controls.php b/include/controls.php
index 8f49e99c5..e6678db9a 100755
--- a/include/controls.php
+++ b/include/controls.php
@@ -181,11 +181,19 @@ function print_feed_multi_select($id, $default_ids = [],
 	}
 }
 
-function print_feed_cat_select($id, $default_id,
-							   $attributes, $include_all_cats = true, $root_id = null, $nest_level = 0) {
+function print_feed_cat_select($id, $default_id, $attributes, $include_all_cats = true,
+	$root_id = null, $nest_level = 0) {
+
+	print format_feed_cat_select($id, $default_id, $attributes, $include_all_cats, $root_id, $nest_level);
+}
+
+function format_feed_cat_select($id, $default_id, $attributes, $include_all_cats = true,
+	$root_id = null, $nest_level = 0) {
+
+	$ret = "";
 
 	if (!$root_id) {
-		print "<select id=\"$id\" name=\"$id\" default=\"$default_id\" $attributes>";
+		$ret .= "<select id=\"$id\" name=\"$id\" default=\"$default_id\" $attributes>";
 	}
 
 	$pdo = Db::pdo();
@@ -215,18 +223,18 @@ function print_feed_cat_select($id, $default_id,
 			$line["title"] = " " . $line["title"];
 
 		if ($line["title"])
-			printf("<option $is_selected value='%d'>%s</option>",
+			$ret .= sprintf("<option $is_selected value='%d'>%s</option>",
 				$line["id"], htmlspecialchars($line["title"]));
 
 		if ($line["num_children"] > 0)
-			print_feed_cat_select($id, $default_id, $attributes,
+			$ret .= format_feed_cat_select($id, $default_id, $attributes,
 				$include_all_cats, $line["id"], $nest_level+1);
 	}
 
 	if (!$root_id) {
 		if ($include_all_cats) {
 			if ($found > 0) {
-				print "<option disabled=\"1\">―――――――――――――――</option>";
+				$ret .= "<option disabled=\"1\">―――――――――――――――</option>";
 			}
 
 			if ($default_id == 0) {
@@ -235,10 +243,12 @@ function print_feed_cat_select($id, $default_id,
 				$is_selected = "";
 			}
 
-			print "<option $is_selected value=\"0\">".__('Uncategorized')."</option>";
+			$ret .= "<option $is_selected value=\"0\">".__('Uncategorized')."</option>";
 		}
-		print "</select>";
+		$ret .= "</select>";
 	}
+
+	return $ret;
 }
 
 function stylesheet_tag($filename, $id = false) {
diff --git a/js/PrefFeedTree.js b/js/PrefFeedTree.js
index 3e3584a9a..c3dda4187 100644
--- a/js/PrefFeedTree.js
+++ b/js/PrefFeedTree.js
@@ -378,35 +378,77 @@ define(["dojo/_base/declare", "dojo/dom-construct", "lib/CheckBoxTree", "dojo/_b
 			}
 		},
 		batchSubscribe: function() {
-			const dialog = new fox.SingleUseDialog({
-				id: "batchSubDlg",
-				title: __("Batch subscribe"),
-				execute: function () {
-					if (this.validate()) {
-						Notify.progress(__("Subscribing to feeds..."), true);
+			xhrJson("backend.php", {op: 'pref-feeds', method: 'batchSubscribe'}, (reply) => {
+				const dialog = new fox.SingleUseDialog({
+					id: "batchSubDlg",
+					title: __("Batch subscribe"),
+					execute: function () {
+						if (this.validate()) {
+							Notify.progress(__("Subscribing to feeds..."), true);
 
-						xhrPost("backend.php", this.attr('value'), () => {
-							Notify.close();
+							xhrPost("backend.php", this.attr('value'), () => {
+								Notify.close();
 
-							const tree = dijit.byId("feedTree");
-							if (tree) tree.reload();
+								const tree = dijit.byId("feedTree");
+								if (tree) tree.reload();
+
+								dialog.hide();
+							});
+						}
+					},
+					content: `
+						<form onsubmit='return false'>
+							${App.FormFields.hidden("op", "pref-feeds")}
+							${App.FormFields.hidden("method", "batchaddfeeds")}
+
+							<header class='horizontal'>
+								${__("One valid feed per line (no detection is done)")}
+							</header>
+
+							<section>
+								<textarea style='font-size : 12px; width : 98%; height: 200px;'
+									dojoType='fox.form.ValidationTextArea' required='1' name='feeds'></textarea>
+
+								${reply.enable_cats ?
+									`<fieldset>
+											<label>${__('Place in category:')}</label>
+											${reply.cat_select}
+									</fieldset>
+									` : ''
+								}
+							</section>
+
+							<div id='feedDlg_loginContainer' style='display : none'>
+								<header>${__("Authentication")}</header>
+								<section>
+									<input dojoType='dijit.form.TextBox' name='login' placeHolder="${__("Login")}">
+									<input placeHolder="${__("Password")}" dojoType="dijit.form.TextBox" type='password'
+										autocomplete='new-password' name='pass'></div>
+								</section>
+							</div>
+
+							<fieldset class='narrow'>
+								<label class='checkbox'><input type='checkbox' name='need_auth' dojoType='dijit.form.CheckBox'
+										onclick='App.displayIfChecked(this, "feedDlg_loginContainer")'>
+									${__('Feeds require authentication.')}
+								</label>
+							</fieldset>
+
+							<footer>
+								<button dojoType='dijit.form.Button' onclick='App.dialogOf(this).execute()' type='submit' class='alt-primary'>
+									${__('Subscribe')}
+								</button>
+								<button dojoType='dijit.form.Button' onclick='App.dialogOf(this).hide()'>
+									${__('Cancel')}
+								</button>
+							</footer>
+						</form>
+					`
+				});
+
+				dialog.show();
 
-							dialog.hide();
-						});
-					}
-				},
-				content: __("Loading, please wait...")
 			});
-
-			const tmph = dojo.connect(dialog, 'onShow', function () {
-				dojo.disconnect(tmph);
-
-				xhrPost("backend.php", {op: 'pref-feeds', method: 'batchSubscribe'}, (transport) => {
-					dialog.attr('content', transport.responseText);
-				})
-			});
-
-			dialog.show();
 		},
 		showInactiveFeeds: function() {
 			xhrJson("backend.php", {op: 'pref-feeds', method: 'inactivefeeds'}, function (reply) {