Source: instantiators/AbstractInstantiator.js

  1. /**
  2.  * Abstract class of all instantiator implementations. An Instantiator will create an instance of a module.
  3.  * You cannot be sure, you get an actual instance of the object, since it could be possible to implement the module
  4.  * as e.g. rpc module which wraps an API.
  5.  * It will keep track of instances to react to circular dependencies.
  6.  *
  7.  * @author Wolfgang Felbermeier (@f3lang)
  8.  */
  9. class AbstractInstantiator {
  11. 	constructor() {
  12. 		this.requestCollection = [];
  13. 	}
  15. 	/**
  16. 	 * Will create a new instance of the requested module
  17. 	 * @param {string} path The file path of the module
  18. 	 * @param {object} config The injection config resolved by the module analyzer
  19. 	 * @param {string} root The tree to work in
  20. 	 * @param {string} requestId The unique request id to identify circular dependencies
  21. 	 */
  22. 	getInstance(path, config, root, requestId) {
  23. 		throw Error('This is an abstract class, use a derived class instead');
  24. 	}
  26. 	/**
  27. 	 * Will check, if the current request has already visited this stage once.
  28. 	 * @param {string} path The file path of the module
  29. 	 * @param {string} root The tree to work in
  30. 	 * @param {string} requestId The unique request id to identify circular dependencies
  31. 	 * @return {boolean} true, if a circular dependency occurred.
  32. 	 */
  33. 	requestIsCircular(path, root, requestId) {
  34. 		if(this.requestCollection.indexOf(requestId  + ':' +  path + ':' + root) > -1) {
  35. 			console.warn("Warning: circular dependency detected for " + requestId  + ':' +  path + ':' + root);
  36. 			return true;
  37. 		}
  38. 		this.requestCollection.push(requestId  + ':' +  path + ':' + root);
  39. 	}
  40. }
  42. module.exports = AbstractInstantiator;
  43. module.exports.inject = [];