Filter that filters whether an object does/doesn't appear in another array (uses underscore.js)

inCollection.js

'use strict';

angular.module('dmn.filters.inCollection', [])

/*
 *  Filters an array of objects (collection) against another collection.
 *  
 *  @param    compareCollection   the collection to compare against
 *  @param    compareField        the field in both collections to compare
 *  @param    filterOnIsIn        Boolean of whether to filter against 'in collection' TRUE, 'not in collection' FALSE.  Defaults to TRUE (is in collection)
 */

.filter('inCollection', function() {
  return function (items, compareCollection, compareField, filterOnIsIn ){
    filterOnIsIn = angular.isDefined(filterOnIsIn) ? filterOnIsIn : true;

    // array to hold filtered
    var filteredItems = [];

    angular.forEach( items, function ( item ) {

      var comparison = {};
      var found = false;

      if( angular.isDefined(item[compareField]) ){
        comparison[ compareField ] = item[ compareField ];

        found = _.findIndex( compareCollection, comparison ) > -1;
      }

      // if found matches the test add it into the the filtered list
      if( found === filterOnIsIn ){
        filteredItems.push( item );
      }

    });

    return filteredItems
  }
});