From bdc9497a00b9cb9187ce090040e584183f57469c Mon Sep 17 00:00:00 2001
From: aashna27 <aashna.mittal27@gmail.com>
Date: Sun, 3 Mar 2019 20:43:05 +0530
Subject: [PATCH] Added debounce for typeahead search optimization

---
 .eslintrc                                   |  3 +++
 app/assets/javascripts/debounce.js          | 18 ++++++++++++++++++
 app/assets/javascripts/restful_typeahead.js |  6 +++---
 3 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 app/assets/javascripts/debounce.js

diff --git a/.eslintrc b/.eslintrc
index 9faa37508e..de99afaf3e 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -9,6 +9,9 @@ env:
   jquery: true
   node: true
 
+parseOptions:
+  sourceType: module
+
 # http://eslint.org/docs/rules/
 rules:
   # Possible Errors
diff --git a/app/assets/javascripts/debounce.js b/app/assets/javascripts/debounce.js
new file mode 100644
index 0000000000..12f2cbc7e0
--- /dev/null
+++ b/app/assets/javascripts/debounce.js
@@ -0,0 +1,18 @@
+// Returns a function, that, as long as it continues to be invoked, will not
+// be triggered. The function will be called after it stops being called for
+// N milliseconds. If `immediate` is passed, trigger the function on the
+// leading edge, instead of the trailing.
+export function debounce(func, wait, immediate) {
+	var timeout;
+	return function() {
+		var context = this, args = arguments;
+		var later = function() {
+			timeout = null;
+			if (!immediate) func.apply(context, args);
+		};
+		var callNow = immediate && !timeout;
+		clearTimeout(timeout);
+		timeout = setTimeout(later, wait);
+		if (callNow) func.apply(context, args);
+	};
+};
\ No newline at end of file
diff --git a/app/assets/javascripts/restful_typeahead.js b/app/assets/javascripts/restful_typeahead.js
index b4e7a0a33e..e720a65aab 100644
--- a/app/assets/javascripts/restful_typeahead.js
+++ b/app/assets/javascripts/restful_typeahead.js
@@ -4,13 +4,13 @@
   search API and the UI components.
   Documentation here: https://github.com/bassjobsen/Bootstrap-3-Typeahead
 **/
+import { debounce } from './debounce.js';
 
 $(function() {
-  $('input.search-query.typeahead').each(function(i, el){
+  $('input.search-query.typeahead').each(debounce(function(i, el){
     var typeahead = $(el).typeahead({
       items: 10,
       minLength: 3,
-      delay: 350,
       showCategoryHeader: true,
       autoSelect: false,
       source: function (query, process) {
@@ -46,5 +46,5 @@ $(function() {
                  showAll: true
                }
     });
-  });
+  }, 350));
 });