fs/lib/readers/Link.js

  1. import AbstractReader from "../AbstractReader.js";
  2. import ResourceFacade from "../ResourceFacade.js";
  3. import {prefixGlobPattern} from "../resourceFactory.js";
  4. import {getLogger} from "@ui5/logger";
  5. const log = getLogger("resources:readers:Link");
  7. /**
  8.  * A reader that allows for rewriting paths segments of all resources passed through it.
  9.  *
  10.  * @example
  11.  * import Link from "@ui5/fs/readers/Link";
  12.  * const linkedReader = new Link({
  13.  *     reader: sourceReader,
  14.  *     pathMapping: {
  15.  *          linkPath: `/app`,
  16.  *          targetPath: `/resources/my-app-name/`
  17.  *      }
  18.  * });
  19.  *
  20.  * // The following resolves with a @ui5/fs/ResourceFacade of the resource
  21.  * // located at "/resources/my-app-name/Component.js" in the sourceReader
  22.  * const resource = await linkedReader.byPath("/app/Component.js");
  23.  *
  24.  * @public
  25.  * @class
  26.  * @alias @ui5/fs/readers/Link
  27.  * @extends @ui5/fs/AbstractReader
  28.  */
  29. class Link extends AbstractReader {
  30. 	/**
  31. 	 * Path mapping for a [Link]{@link @ui5/fs/readers/Link}
  32. 	 *
  33. 	 * @public
  34. 	 * @typedef {object} @ui5/fs/readers/Link/PathMapping
  35. 	 * @property {string} linkPath Path to match and replace in the requested path or pattern
  36. 	 * @property {string} targetPath Path to use as a replacement in the request for the source reader
  37. 	 */
  39. 	/**
  40. 	 * Constructor
  41. 	 *
  42.  	 * @public
  43. 	 * @param {object} parameters Parameters
  44. 	 * @param {@ui5/fs/AbstractReader} parameters.reader The resource reader or collection to wrap
  45. 	 * @param {@ui5/fs/readers/Link/PathMapping} parameters.pathMapping
  46. 	 */
  47. 	constructor({reader, pathMapping}) {
  48. 		super();
  49. 		if (!reader) {
  50. 			throw new Error(`Missing parameter "reader"`);
  51. 		}
  52. 		if (!pathMapping) {
  53. 			throw new Error(`Missing parameter "pathMapping"`);
  54. 		}
  55. 		this._reader = reader;
  56. 		this._pathMapping = pathMapping;
  57. 		Link._validatePathMapping(pathMapping);
  58. 	}
  60. 	/**
  61. 	 * Locates resources by glob.
  62. 	 *
  63. 	 * @private
  64. 	 * @param {string|string[]} patterns glob pattern as string or an array of
  65. 	 *         glob patterns for virtual directory structure
  66. 	 * @param {object} options glob options
  67. 	 * @param {@ui5/fs/tracing/Trace} trace Trace instance
  68. 	 * @returns {Promise<@ui5/fs/Resource[]>} Promise resolving to list of resources
  69. 	 */
  70. 	async _byGlob(patterns, options, trace) {
  71. 		if (!(patterns instanceof Array)) {
  72. 			patterns = [patterns];
  73. 		}
  74. 		patterns = patterns.map((pattern) => {
  75. 			if (pattern.startsWith(this._pathMapping.linkPath)) {
  76. 				pattern = pattern.substr(this._pathMapping.linkPath.length);
  77. 			}
  78. 			return prefixGlobPattern(pattern, this._pathMapping.targetPath);
  79. 		});
  81. 		// Flatten prefixed patterns
  82. 		patterns = Array.prototype.concat.apply([], patterns);
  84. 		// Keep resource's internal path unchanged for now
  85. 		const resources = await this._reader._byGlob(patterns, options, trace);
  86. 		return resources.map((resource) => {
  87. 			const resourcePath = resource.getPath();
  88. 			if (resourcePath.startsWith(this._pathMapping.targetPath)) {
  89. 				return new ResourceFacade({
  90. 					resource,
  91. 					path: this._pathMapping.linkPath + resourcePath.substr(this._pathMapping.targetPath.length)
  92. 				});
  93. 			}
  94. 		});
  95. 	}
  97. 	/**
  98. 	 * Locates resources by path.
  99. 	 *
  100. 	 * @private
  101. 	 * @param {string} virPath Virtual path
  102. 	 * @param {object} options Options
  103. 	 * @param {@ui5/fs/tracing/Trace} trace Trace instance
  104. 	 * @returns {Promise<@ui5/fs/Resource>} Promise resolving to a single resource
  105. 	 */
  106. 	async _byPath(virPath, options, trace) {
  107. 		if (!virPath.startsWith(this._pathMapping.linkPath)) {
  108. 			return null;
  109. 		}
  110. 		const targetPath = this._pathMapping.targetPath + virPath.substr(this._pathMapping.linkPath.length);
  111. 		log.silly(`byPath: Rewriting virtual path ${virPath} to ${targetPath}`);
  113. 		const resource = await this._reader._byPath(targetPath, options, trace);
  114. 		if (resource) {
  115. 			return new ResourceFacade({
  116. 				resource,
  117. 				path: this._pathMapping.linkPath + resource.getPath().substr(this._pathMapping.targetPath.length)
  118. 			});
  119. 		}
  120. 		return null;
  121. 	}
  123. 	static _validatePathMapping({linkPath, targetPath}) {
  124. 		if (!linkPath) {
  125. 			throw new Error(`Path mapping is missing attribute "linkPath"`);
  126. 		}
  127. 		if (!targetPath) {
  128. 			throw new Error(`Path mapping is missing attribute "targetPath"`);
  129. 		}
  130. 		if (!linkPath.endsWith("/")) {
  131. 			throw new Error(`Link path must end with a slash: ${linkPath}`);
  132. 		}
  133. 		if (!targetPath.endsWith("/")) {
  134. 			throw new Error(`Target path must end with a slash: ${targetPath}`);
  135. 		}
  136. 	}
  137. }
  139. export default Link;