fs/lib/readers/Filter.js

  1. import AbstractReader from "../AbstractReader.js";
  3. /**
  4.  * A reader that allows dynamic filtering of resources passed through it
  5.  *
  6.  * @public
  7.  * @class
  8.  * @alias @ui5/fs/readers/Filter
  9.  * @extends @ui5/fs/AbstractReader
  10.  */
  11. class Filter extends AbstractReader {
  12. 	/**
  13. 	* Filter callback
  14. 	*
  15. 	* @public
  16. 	* @callback @ui5/fs/readers/Filter~callback
  17. 	* @param {@ui5/fs/Resource} resource Resource to test
  18. 	* @returns {boolean} Whether to keep the resource
  19. 	*/
  21. 	/**
  22. 	 * Constructor
  23. 	 *
  24.  	 * @public
  25. 	 * @param {object} parameters Parameters
  26. 	 * @param {@ui5/fs/AbstractReader} parameters.reader The resource reader or collection to wrap
  27. 	 * @param {@ui5/fs/readers/Filter~callback} parameters.callback
  28. 	 * 				Filter function. Will be called for every resource read through this reader.
  29. 	 */
  30. 	constructor({reader, callback}) {
  31. 		super();
  32. 		if (!reader) {
  33. 			throw new Error(`Missing parameter "reader"`);
  34. 		}
  35. 		if (!callback) {
  36. 			throw new Error(`Missing parameter "callback"`);
  37. 		}
  38. 		this._reader = reader;
  39. 		this._callback = callback;
  40. 	}
  42. 	/**
  43. 	 * Locates resources by glob.
  44. 	 *
  45. 	 * @private
  46. 	 * @param {string|string[]} pattern glob pattern as string or an array of
  47. 	 *         glob patterns for virtual directory structure
  48. 	 * @param {object} options glob options
  49. 	 * @param {@ui5/fs/tracing/Trace} trace Trace instance
  50. 	 * @returns {Promise<@ui5/fs/Resource[]>} Promise resolving to list of resources
  51. 	 */
  52. 	async _byGlob(pattern, options, trace) {
  53. 		const result = await this._reader._byGlob(pattern, options, trace);
  54. 		return result.filter(this._callback);
  55. 	}
  57. 	/**
  58. 	 * Locates resources by path.
  59. 	 *
  60. 	 * @private
  61. 	 * @param {string} virPath Virtual path
  62. 	 * @param {object} options Options
  63. 	 * @param {@ui5/fs/tracing/Trace} trace Trace instance
  64. 	 * @returns {Promise<@ui5/fs/Resource>} Promise resolving to a single resource
  65. 	 */
  66. 	async _byPath(virPath, options, trace) {
  67. 		const result = await this._reader._byPath(virPath, options, trace);
  68. 		if (result && !this._callback(result)) {
  69. 			return null;
  70. 		}
  71. 		return result;
  72. 	}
  73. }
  75. export default Filter;