ng-options and unique filter not displaying angular.js

Problem

In my javascript I have an array

$scope.quoteList =        
[
{
select: false,
laymansDescription: "Nathan",
quoteNumber: "ING-70440-21",
version: "02",
quoteDate: "Feb 5,2013",
expirationDate: "Aug 5,2013",
internalNotes: "This quote is using test data",
},
{
select: false,
laymansDescription: "Mitch",
quoteNumber: "ING-70440-01",
version: "02",
quoteDate: "Feb 5,2013",
expirationDate: "Aug 5,2013",
internalNotes: "This quote is using test data",
},
{
select: false,
laymansDescription: "Stephen",
quoteNumber: "ING-70440-01",
version: "02",
quoteDate: "Feb 5,2013",
expirationDate: "Aug 5,2013",
internalNotes: "This quote is using test data",
}
];

And I am trying to make a selector that will only show unique quoteNumbers ie. ING-70440–21 and ING-70440–01. However when I try to use the ‘unique’ option in angular, nothing is showing up.

<select class="form-control" ng-options="quote.quoteNumber for quote in quoteList | unique:'quoteNumber'" ng-model="quoteModel1" />

It works fine without the unique tag. What am I doing wrong? I pretty new to angular so it might be something really simple.

Problem courtesy of: MitchVz

Solution

AngularJS does not have a built-in unique filter. You can do something like this to make one of your own:

app.filter('unique', function() {
return function(input, key) {
var unique = {};
var uniqueList = [];
for(var i = 0; i < input.length; i++){
if(typeof unique[input[i][key]] == "undefined"){
unique[input[i][key]] = "";
uniqueList.push(input[i]);
}
}
return uniqueList;
};
});

Solution courtesy of: AlwaysALearner

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