From http://plnkr.co/edit/LCMG2vqUtlgtbw6dZahh?p=preview

Caching requests in Angular

var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope, $http, $cacheFactory) {
  // using $cacheFactory to make sure we clear
  // the cache and then re-set it when cache is false
  // in $scope.makeRequest
  var httpCache = $cacheFactory.get('$http');

  $scope.makeRequest = function (cache) {
    if(!cache) httpCache.remove('response.php');
    $http({
      method: 'GET',
      cache: cache,
      // obviously PHP doesn't work in Plnkr,
      // but if you put this on a PHP server,
      // the cache would flush itself
      // as expected, and only get a new rand #
      // if you click "Non-Cached Request"
      url: 'response.php'
    }).then(function(result) {
      console.log('Got result: ', result.data);
      if(!cache) httpCache.put('response.php', result.data);
    });
  };
});