From ffa178cf7a6a40fabd13047474f4b4702c8d71bb Mon Sep 17 00:00:00 2001
From: Steve Howell <steve@humbughq.com>
Date: Mon, 22 Jul 2013 23:22:51 -0400
Subject: [PATCH] Suggest "widening" searches in search autocomplete.

This will allow you to always get Home from the search box,
as well as easily backing out narrows.

(imported from commit 68bcfc83ce0428645f4e734ae46f9589cb562a86)
---
 zephyr/static/js/search.js | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/zephyr/static/js/search.js b/zephyr/static/js/search.js
index 3dec582052..f63f0bf8ce 100644
--- a/zephyr/static/js/search.js
+++ b/zephyr/static/js/search.js
@@ -340,6 +340,32 @@ function get_topic_suggestions(query, query_operators) {
     });
 }
 
+function get_operator_subset_suggestions(query, operators) {
+    // If you have stream:foo topic:x search:needle, then
+    // suggest "stream:foo" and "stream:foo topic:x" so that
+    // power users can use search as a quick mouse-free way
+    // to de-narrow.  This won't cause too much clutter, as
+    // you generally only have 1 to 3 operators, and this gives
+    // N-1 additional suggestions.
+    if (operators.length < 1) {
+        return [];
+    }
+
+    var i;
+    var suggestions = [];
+
+    for (i = 0; i < operators.length; ++i) {
+        var subset = operators.slice(0, i);
+        var search_string = narrow.unparse(subset);
+        var description = describe(subset);
+        var suggestion = {description: description, search_string: search_string};
+        suggestions.push(suggestion);
+    }
+
+    return suggestions;
+}
+
+
 function get_special_filter_suggestions(query, operators) {
     if (operators.length >= 2) {
         return [];
@@ -403,6 +429,9 @@ exports.initialize = function () {
             suggestions = get_special_filter_suggestions(query, operators);
             result = result.concat(suggestions);
 
+            suggestions = get_operator_subset_suggestions(query, operators);
+            result = result.concat(suggestions);
+
             suggestions = get_stream_suggestions(query);
             result = result.concat(suggestions);