server/lib/middleware/MiddlewareUtil.js

  1. /**
  2.  * Convenience functions for UI5 Server middleware.
  3.  * An instance of this class is passed to every standard UI5 Server middleware.
  4.  * Custom middleware that define a specification version >= 2.0 will also receive an instance
  5.  * of this class as part of the parameters of their create-middleware function.
  6.  *
  7.  * The set of functions that can be accessed by a custom middleware depends on the specification
  8.  * version defined for the extension.
  9.  *
  10.  * @public
  11.  * @memberof module:@ui5/server.middleware
  12.  */
  13. class MiddlewareUtil {
  14. 	/**
  15. 	 * Get an interface to an instance of this class that only provides those functions
  16. 	 * that are supported by the given custom middleware extension specification version.
  17. 	 *
  18. 	 * @param {string} specVersion Specification Version of custom middleware extension
  19. 	 * @returns {object} An object with bound instance methods supported by the given specification version
  20. 	 */
  21. 	getInterface(specVersion) {
  22. 		const baseInterface = {
  23. 			getPathname: this.getPathname.bind(this),
  24. 			getMimeInfo: this.getMimeInfo.bind(this)
  25. 		};
  26. 		switch (specVersion) {
  27. 		case "0.1":
  28. 		case "1.0":
  29. 		case "1.1":
  30. 			return undefined;
  31. 		case "2.0":
  32. 		case "2.1":
  33. 		case "2.2":
  34. 		case "2.3":
  35. 		case "2.4":
  36. 		case "2.5":
  37. 		case "2.6":
  38. 			return baseInterface;
  39. 		default:
  40. 			throw new Error(`MiddlewareUtil: Unknown or unsupported Specification Version ${specVersion}`);
  41. 		}
  42. 	}
  44. 	/**
  45. 	 * Returns the [pathname]{@link https://developer.mozilla.org/en-US/docs/Web/API/URL/pathname}
  46. 	 * of a given request. Any escape sequences will be decoded.
  47. 	 * </br></br>
  48. 	 * This method is only available to custom middleware extensions defining
  49. 	 * <b>Specification Version 2.0 and above</b>.
  50. 	 *
  51. 	 * @param {object} req Request object
  52. 	 * @returns {string} [Pathname]{@link https://developer.mozilla.org/en-US/docs/Web/API/URL/pathname}
  53. 	 * of the given request
  54. 	 * @public
  55. 	 */
  56. 	getPathname(req) {
  57. 		const parseurl = require("parseurl");
  58. 		let {pathname} = parseurl(req);
  59. 		pathname = decodeURIComponent(pathname);
  60. 		return pathname;
  61. 	}
  63. 	/**
  64. 	 * MIME Info
  65. 	 *
  66. 	 * @example
  67. 	 * const mimeInfo = {
  68. 	 * 	"type": "text/html",
  69. 	 * 	"charset": "utf-8",
  70. 	 * 	"contentType": "text/html; charset=utf-8"
  71. 	 * };
  72. 	 *
  73. 	 * @public
  74. 	 * @typedef {object} MimeInfo
  75. 	 * @property {string} type Detected content-type for the given resource path
  76. 	 * @property {string} charset Default charset for the detected content-type
  77. 	 * @property {string} contentType Calculated content-type header value
  78. 	 * @memberof module:@ui5/server.middleware.MiddlewareUtil
  79. 	 */
  80. 	/**
  81. 	 * Returns MIME information derived from a given resource path.
  82. 	 * </br></br>
  83. 	 * This method is only available to custom middleware extensions defining
  84. 	 * <b>Specification Version 2.0 and above</b>.
  85. 	 *
  86. 	 * @param {object} resourcePath
  87. 	 * @returns {module:@ui5/server.middleware.MiddlewareUtil.MimeInfo}
  88. 	 * @public
  89. 	 */
  90. 	getMimeInfo(resourcePath) {
  91. 		const mime = require("mime-types");
  92. 		const type = mime.lookup(resourcePath) || "application/octet-stream";
  93. 		const charset = mime.charset(type);
  94. 		return {
  95. 			type,
  96. 			charset,
  97. 			contentType: type + (charset ? "; charset=" + charset : "")
  98. 		};
  99. 	}
  100. }
  102. module.exports = MiddlewareUtil;