Datepicker js optimization

Created by: tonmoy18

The date picker ID prefix and number are in different vars Pro: no need to read, slice and append to ID every time Con: the original ID is changed.

app/assets/javascripts/datarepo/datepicker.js

 var datepickerClass = '.datarepo-datepicker';
+var datepickerId = 'datarepo-datepicker-';
 var datepickerNumber = 0;
 var datepickerOpts = {
     changeMonth: true,
@@ -8,16 +9,13 @@ var datepickerOpts = {
 
 function addDatepicker(mutation) {
     for (var i = 0; i < mutation.addedNodes.length; ++i) {
-        var node = $(mutation.addedNodes[i]).find('input').first();
-        if (node.length && !node.data('datepicker')) {
-            node.removeClass('hasDatepicker');
-            if (node.attr('id').endsWith('-' + datepickerNumber)) {
-                node.attr('id', node.attr('id').slice(0, 0-('-' + datepickerNumber).length));
-                ++datepickerNumber;
-            }
-            node.attr('id', node.attr('id') + '-' + datepickerNumber);
-            node.datepicker();
-        }
+	var node = $(mutation.addedNodes[i]).find('input.hasDatepicker');
+	if (node.length) {
+		node.removeClass('hasDatepicker');
+		node.attr('id', datepickerId + datepickerNumber);
+		datepickerNumber++;
+		node.datepicker();
+	}
     }
 }
 
@@ -25,8 +23,7 @@ Blacklight.onLoad(function() {
     if ($(datepickerClass).length) {
         $.datepicker.setDefaults(datepickerOpts);
         $(datepickerClass).each(function() {
-            $(this).datepicker();
-
+	    $(this).datepicker();
             var datepickerObserver = new MutationObserver(function(mutations) {
                 mutations.forEach(addDatepicker);
             });