CODEWITHSUNDEEP
javascriptjsonangularjs
Adrian
Adrian

Reputation: 2012

Extract date from last item in JSON object (AngularJS)

I am dynamically creating an object on a web app using AngularJS. The idea is that the user can load new events as they click a button, for this to work I need to get the date of the last one so Ill know which ones to load next.

This is the code that generates the JSON object

    services.getEvents().then(function(data){
        $scope.events = data.data;
    });

and my html...

    <li ng-repeat="event in events | orderBy:'-event_date' ">
      <span>{{event.event_date}},{{event.event_name}}, {{event.event_venue}}, {{event.event_description}} </span>
    </li>

An example of one event...

{
 "event_id":"1",
 "event_name":"Event 1",
 "event_date":"2014-09-26 00:00:00",
 "event_venue":"Limerick",
 "event_description":"stuff"
}

Is it possible to extract the latest date from a list of these so I can send it back to the API? Or am I going about this a wrong way altogether.

Im also using this an opportunity to learn AngularJS

Upvotes: 1

Views: 1607

Answers (3)

sylwester
sylwester

Reputation: 16498

var app = angular.module("app", []);


function MainCtrl ($filter) {
this.data = [
  
  {
 "event_id":"1",
 "event_name":"Event 1",
 "event_date":"2014-05-26 00:00:00",
 "event_venue":"Limerick",
 "event_description":"stuff"
},{
 "event_id":"2",
 "event_name":"Event 1",
 "event_date":"2015-09-26 00:00:00",
 "event_venue":"Limerick",
 "event_description":"stuff"
},{
 "event_id":"3",
 "event_name":"Event 1",
 "event_date":"2014-9-27 00:00:00",
 "event_venue":"Limerick",
 "event_description":"stuff"
}
  
];
 this.lastOne =$filter('orderBy')(this.data,'-event_date')[this.data.length-1].event_date ;
 }





angular.module("app").controller("MainCtrl", MainCtrl);
<html ng-app="app">
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<body ng-controller="MainCtrl as vm">
  <div class="container">
     <h3>Latest One:{{vm.lastOne}}</h3>
    
  </div>
 
</body>
  </html>

Upvotes: 1

Keith
Keith

Reputation: 738

If you make your server side code return an array sorted by descending date, you could just take the date off the first item in your array. Something like:

events[0].event_date;

Failing that, you could do the sorting on the client side with something like:

events.sort(function(a, b){return new Date(a.event_date) < new Date(b.event_date);});

Then get the value of: 

events[0].event_date;

Upvotes: 0

Nordfjord
Nordfjord

Reputation: 162

To access the last element of an array use length -1

events[events.length - 1].event_date

if the response from the server is not sorted in any way you should filter first

var sortedArray = $filter('orderBy')($scope.events, '-event_date');
var lastDate = sortedArray[sortedArray.length - 1].event_date

hope this gets you on the way.

Upvotes: 1

Related Questions