partition array filter - distribute an array into columns #angularjs #array #partition #columns

ng1-partition-array.filter.js

Example usage: <!-- ngRepeat: thing in things | limitTo:6 | partition:3 -->

limitTo = max items to return
partition = how many arrays 

.filter('partition', [ '$cacheFactory', function($cacheFactory) {
  var arrayCache = $cacheFactory('partition');
  var filter = function(arr, size) {
    if (!arr) { return; }
    var newArr = [];
    for (var i=0; i<arr.length; i+=size) {
        newArr.push(arr.slice(i, i+size));        
    }
    var cachedParts;
    var arrString = JSON.stringify(arr);
    cachedParts = arrayCache.get(arrString+size); 
    if (JSON.stringify(cachedParts) === JSON.stringify(newArr)) {
      return cachedParts;
    }
    arrayCache.put(arrString+size, newArr);
    return newArr;
  };
  return filter;
}])