Source: filter/filterChainPromiseExecutor.js

  1. /**
  2.  * @author Sloan Seaman 
  3.  * @copyright 2016 and on
  4.  * @version .1
  5.  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0
  6.  */
  8. /** @private */
  9. var AbstractPromiseExecutor = require('../executor/abstractPromiseExecutor.js');
  10. var log = require('winston-simple').getLogger('FilterChainPromiseExecutor');
  12. /**
  13.  * The FilterChainExecutor is the 'engine' of SkillVC in that it controls the execution of
  14.  * all the registered filters (including intent handling which is treated as a filter).
  15.  *
  16.  * This works by iterating over the list of registered filters and, when a `Promise` is discovered, waits
  17.  * until the completion, and then continues over the loop
  18.  * 
  19.  * @constructor
  20.  * @see  {@link Filter}
  21.  * @param {Filter} [preFilters]  The pre filters to execute
  22.  * @param {Filter} [postFilters] The post filters to execute
  23.  */
  24. function FilterChainPromiseExecutor(preFilters, postFilters) {
  25. 	this._pre = preFilters;
  26. 	this._post = postFilters;
  27. }
  29. FilterChainPromiseExecutor.prototype = Object.create(AbstractPromiseExecutor.prototype);
  30. FilterChainPromiseExecutor.prototype.constructor = FilterChainPromiseExecutor;
  32. /**
  33.  * Start the execution
  34.  * 
  35.  * @function
  36.  * @param  {SVContext} svContext The SVContext to use for execution
  37.  * @returns {Promise} The `Promise` that can be used to wait until this completes
  38.  */
  39. FilterChainPromiseExecutor.prototype.execute = function(svContext) {
  40. 	var fcm = this; // to control scoping in the promises
  42. 	return new Promise(function(resolve, reject) {
  43. 		log.info("Starting Filter Chain Execution");
  44. 		fcm._doExecute('executePre', fcm._pre, svContext)
  45. 			.then(fcm._doExecute.bind(this, 'executePost', fcm._post, svContext)) // use bind so I don't have to wrap with function()
  46. 			.then(function() {
  47. 				log.info("Filter Chain Execution completed");
  48. 				resolve();
  49. 			})
  50. 			.catch(function(err) {
  51. 				log.error("Error in chain. "+err);
  52. 				reject();
  53. 			});
  54. 	});
  55. };
  57. module.exports = FilterChainPromiseExecutor;