nodulator/node_modules_bak/rest/util/uriTemplate.js

Complete NodeJS Framework for Restfull APIs

/*
 * Copyright 2015 the original author or authors
 * @license MIT, see LICENSE.txt for details
 *
 * @author Scott Andrews
 */

(function (define) {
	'use strict';

	var undef;

	define(function (require) {

		var uriEncoder, operations, prefixRE;

		uriEncoder = require('./uriEncoder');

		prefixRE = /^([^:]*):([0-9]+)$/;
		operations = {
			'':  { first: '',  separator: ',', named: false, empty: '',  encoder: uriEncoder.encode },
			'+': { first: '',  separator: ',', named: false, empty: '',  encoder: uriEncoder.encodeURL },
			'#': { first: '#', separator: ',', named: false, empty: '',  encoder: uriEncoder.encodeURL },
			'.': { first: '.', separator: '.', named: false, empty: '',  encoder: uriEncoder.encode },
			'/': { first: '/', separator: '/', named: false, empty: '',  encoder: uriEncoder.encode },
			';': { first: ';', separator: ';', named: true,  empty: '',  encoder: uriEncoder.encode },
			'?': { first: '?', separator: '&', named: true,  empty: '=', encoder: uriEncoder.encode },
			'&': { first: '&', separator: '&', named: true,  empty: '=', encoder: uriEncoder.encode },
			'=': { reserved: true },
			',': { reserved: true },
			'!': { reserved: true },
			'@': { reserved: true },
			'|': { reserved: true }
		};

		function apply(operation, expression, params) {
			/*jshint maxcomplexity:11 */
			return expression.split(',').reduce(function (result, variable) {
				var opts, value;

				opts = {};
				if (variable.slice(-1) === '*') {
					variable = variable.slice(0, -1);
					opts.explode = true;
				}
				if (prefixRE.test(variable)) {
					var prefix = prefixRE.exec(variable);
					variable = prefix[1];
					opts.maxLength = parseInt(prefix[2]);
				}

				variable = uriEncoder.decode(variable);
				value = params[variable];

				if (value === undef || value === null) {
					return result;
				}
				if (Array.isArray(value)) {
					result += value.reduce(function (result, value) {
						if (result.length) {
							result += opts.explode ? operation.separator : ',';
							if (operation.named && opts.explode) {
								result += operation.encoder(variable);
								result += value.length ? '=' : operation.empty;
							}
						}
						else {
							result += operation.first;
							if (operation.named) {
								result += operation.encoder(variable);
								result += value.length ? '=' : operation.empty;
							}
						}
						result += operation.encoder(value);
						return result;
					}, '');
				}
				else if (typeof value === 'object') {
					result += Object.keys(value).reduce(function (result, name) {
						if (result.length) {
							result += opts.explode ? operation.separator : ',';
						}
						else {
							result += operation.first;
							if (operation.named && !opts.explode) {
								result += operation.encoder(variable);
								result += value[name].length ? '=' : operation.empty;
							}
						}
						result += operation.encoder(name);
						result += opts.explode ? '=' : ',';
						result += operation.encoder(value[name]);
						return result;
					}, '');
				}
				else {
					value = String(value);
					if (opts.maxLength) {
						value = value.slice(0, opts.maxLength);
					}
					result += result.length ? operation.separator : operation.first;
					if (operation.named) {
						result += operation.encoder(variable);
						result += value.length ? '=' : operation.empty;
					}
					result += operation.encoder(value);
				}

				return result;
			}, '');
		}

		function expandExpression(expression, params) {
			var operation;

			operation = operations[expression.slice(0,1)];
			if (operation) {
				expression = expression.slice(1);
			}
			else {
				operation = operations[''];
			}

			if (operation.reserved) {
				throw new Error('Reserved expression operations are not supported');
			}

			return apply(operation, expression, params);
		}

		function expandTemplate(template, params) {
			var start, end, uri;

			uri = '';
			end = 0;
			while (true) {
				start = template.indexOf('{', end);
				if (start === -1) {
					// no more expressions
					uri += template.slice(end);
					break;
				}
				uri += template.slice(end, start);
				end = template.indexOf('}', start) + 1;
				uri += expandExpression(template.slice(start + 1, end - 1), params);
			}

			return uri;
		}

		return {

			/**
			 * Expand a URI Template with parameters to form a URI.
			 *
			 * Full implementation (level 4) of rfc6570.
			 * @see https://tools.ietf.org/html/rfc6570
			 *
			 * @param {string} template URI template
			 * @param {Object} [params] params to apply to the template durring expantion
			 * @returns {string} expanded URI
			 */
			expand: expandTemplate

		};

	});

}(
	typeof define === 'function' && define.amd ? define : function (factory) { module.exports = factory(require); }
	// Boilerplate for AMD and Node
));