Using AngularJS how could I randomize the order of a collection?

Question

How would you order a list of items in AngularJS in random order? I was thinking that the built-in orderBy filter would work but I'm not sure how without adding some additional data to the model. Something like would be great.

item in items | orderBy:random

My next thought was to create a custom filter but I'd prefer to avoid that if there is something better already available.

Answer 1

EDIT Warning!: These results are skewed, don't use this. This answer is only left as a warning until further editing.

Explanation: There should be an equal chance of any item being in the first position, but the actual percent chance after 10,000 iterations of, for example, 6 items, ends up being

1: ~28%, 2: ~10%, 3: ~14%, 4: ~20%, 5: ~12%, 6: ~15%

https://jsfiddle.net/sh0ber/km9cqvpf/

orderBy can take a function parameter, just like array.sort so you can use your HTML above and define a function random on the scope like:

$scope.random = function(){
    return 0.5 - Math.random();
};

This will return a random value sometimes negative, sometimes positive, sometimes 0, which will randomly sort the array.

Answer 2

Doing a quick fiddle sh0ber method seems to work well: http://jsfiddle.net/owenmead/fa4v8/1/

<div ng-controller="MyCtrl">
  <p ng-repeat="i in list|orderBy:random">{{i}}</p>
</div>

function MyCtrl($scope) {
  $scope.list = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];
  $scope.random = function() {
    return 0.5 - Math.random();
  }
}

Angular's orderBy uses JavaScript's sort() on a copy of the list. Looking at another answer, certain browsers are stable in their sort, others are not. Perhaps just test the fiddle in a few browsers and you should be good to go: Array.sort Sorting Stability in Different Browsers

PS. Couldn't comment on sh0ber's answer as I don't have 50 rep