I want to use ko.utils.arrayGetDistinctValues
like in this fiddle on more than one property in an array so I map the array to an array of just the two propertie
As an update to Michael Best's answer, here is something using more recent KnockoutJS v3 code conventions (e.g. dependentObservable = computed and using arrayFilter method):
var uniqueSizes = ko.computed({read: function() {
var seen = [];
return ko.utils.arrayFilter(viewModel.collection.vendorGearFilters(), function(f) {
return seen.indexOf(f['size_abbr']()) == -1 && seen.push(f['size_abbr']());
});
}, deferEvaluation: true})