How to find out if variable value has changed? (angularJS)

Question

In HTML I have this:

<input id="Search" type="text" placeholder="Search Images.." ng-model="data" 
       ng-keypress="($event.charCode==13)? searchMore() : return">

This is basically input field which acts as search.

In controller I just receive the value which is passed to input: $scope.data

I want to determine somehow if the search term has changed so that I can wipe out results array if it did or append if just more results of the same search term came.

How to determine that $scope.data now contains a different string? If I will just set something like this:

$scope.savedData = $scope.data

This new variable will be overwritten all the time with new data.

charlietfl · Accepted Answer · 2017-04-14 20:24:09Z

2

ng-change is one easy way

<input id="Search" 
      type="text" 
      placeholder="Search Images.." 
      ng-model="data" 
      ng-change="clearResults()"
      ng-keypress="($event.charCode==13)? searchMore() : return">

edited Apr 14, 2017 at 20:24

answered Apr 14, 2017 at 20:00

charlietfl

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2 Comments

funguy Over a year ago

ng-change is triggered on every key stroke and I am doing an API call only on keystroke (enter). Doing API calls on every key stroke might not be the best approach.

Radek Anuszewski Over a year ago

@funguy You can use debounce for ng-model-options, so for example with ng-model-options: {debounce: 1000} when user finish typing it will wait a 1000 miliseconds and then update model and fetch data. Of course it should react as-is on enter. And it depends on you how you implement clearResults - it can be simple boolean flag, without call itself. For call you have searchMore

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