fs/lib/ReaderCollectionPrioritized.js

  1. import AbstractReader from "./AbstractReader.js";
  3. /**
  4.  * Prioritized Resource Locator Collection
  5.  *
  6.  * @public
  7.  * @class
  8.  * @alias @ui5/fs/ReaderCollectionPrioritized
  9.  * @extends @ui5/fs/AbstractReader
  10.  */
  11. class ReaderCollectionPrioritized extends AbstractReader {
  12. 	/**
  13. 	 * The constructor.
  14. 	 *
  15. 	 * @param {object} parameters
  16. 	 * @param {string} parameters.name The collection name
  17. 	 * @param {@ui5/fs/AbstractReader[]} [parameters.readers]
  18. 	 *   Prioritized list of resource readers (tried in the order provided).
  19. 	 *   If none are provided, the collection will never return any results.
  20. 	 */
  21. 	constructor({readers, name}) {
  22. 		super(name);
  24. 		// Remove any undefined (empty) readers from array
  25. 		this._readers = readers.filter(($) => $);
  26. 	}
  28. 	/**
  29. 	 * Locates resources by glob.
  30. 	 *
  31. 	 * @private
  32. 	 * @param {string|string[]} pattern glob pattern as string or an array of
  33. 	 *         glob patterns for virtual directory structure
  34. 	 * @param {object} options glob options
  35. 	 * @param {@ui5/fs/tracing.Trace} trace Trace instance
  36. 	 * @returns {Promise<@ui5/fs/Resource[]>} Promise resolving to list of resources
  37. 	 */
  38. 	_byGlob(pattern, options, trace) {
  39. 		return Promise.all(this._readers.map(function(resourceLocator) {
  40. 			return resourceLocator._byGlob(pattern, options, trace);
  41. 		})).then((result) => {
  42. 			const files = Object.create(null);
  43. 			const resources = [];
  44. 			// Prefer files found in preceding resource locators
  45. 			for (let i = 0; i < result.length; i++) {
  46. 				for (let j = 0; j < result[i].length; j++) {
  47. 					const resource = result[i][j];
  48. 					const path = resource.getPath();
  49. 					if (!files[path]) {
  50. 						files[path] = true;
  51. 						resources.push(resource);
  52. 					}
  53. 				}
  54. 			}
  56. 			trace.collection(this._name);
  57. 			return resources;
  58. 		});
  59. 	}
  61. 	/**
  62. 	 * Locates resources by path.
  63. 	 *
  64. 	 * @private
  65. 	 * @param {string} virPath Virtual path
  66. 	 * @param {object} options Options
  67. 	 * @param {@ui5/fs/tracing.Trace} trace Trace instance
  68. 	 * @returns {Promise<@ui5/fs/Resource|null>}
  69. 	 *   Promise resolving to a single resource or <code>null</code> if no resource is found
  70. 	 */
  71. 	_byPath(virPath, options, trace) {
  72. 		const that = this;
  73. 		const byPath = (i) => {
  74. 			if (i > this._readers.length - 1) {
  75. 				return null;
  76. 			}
  77. 			return this._readers[i]._byPath(virPath, options, trace).then((resource) => {
  78. 				if (resource) {
  79. 					resource.pushCollection(that._name);
  80. 					return resource;
  81. 				} else {
  82. 					return byPath(++i);
  83. 				}
  84. 			});
  85. 		};
  86. 		return byPath(0);
  87. 	}
  88. }
  90. export default ReaderCollectionPrioritized;