icingaweb2/public/js/define.js

119 lines
3.2 KiB
JavaScript

/*! Icinga Web 2 | (c) 2020 Icinga GmbH | GPLv2+ */
(function(window) {
'use strict';
/**
* Provide a reference to be later required by foreign code
*
* @param {string} name Optional, defaults to the name (and path) of the file
* @param {string[]} requirements Optional, list of required references, may be relative if from the same package
* @param {function} factory Required, function that accepts as many params as there are requirements and that
* produces a value to be referenced
*/
var define = function (name, requirements, factory) {
define.defines[name] = {
requirements: requirements,
factory: factory,
ref: null
}
define.resolve(name);
}
/**
* Return whether the given name references a value
*
* @param {string} name The absolute name of the reference
* @return {boolean}
*/
define.has = function (name) {
return name in define.defines && define.defines[name]['ref'] !== null;
}
/**
* Get the value of a reference
*
* @param {string} name The absolute name of the reference
* @return {*}
*/
define.get = function (name) {
return define.defines[name]['ref'];
}
/**
* Set the value of a reference
*
* @param {string} name The absolute name of the reference
* @param {*} ref The value to reference
*/
define.set = function (name, ref) {
define.defines[name]['ref'] = ref;
}
/**
* Resolve a reference and, if successful, dependent references
*
* @param {string} name The absolute name of the reference
* @return {boolean}
*/
define.resolve = function (name) {
var requirements = define.defines[name]['requirements'];
var exports, ref;
var requiredRefs = [];
for (var i = 0; i < requirements.length; i++) {
if (define.has(requirements[i])) {
ref = define.get(requirements[i]);
} else if (requirements[i] === 'exports') {
exports = ref = {};
} else {
return false;
}
requiredRefs.push(ref);
}
var factory = define.defines[name]['factory'];
var resolved = factory.apply(null, requiredRefs);
if (typeof exports === 'object') {
if (typeof resolved !== 'undefined') {
throw new Error('Factory for ' + name + ' returned, although exports were populated');
}
resolved = exports;
}
define.set(name, resolved);
for (var definedName in define.defines) {
if (define.defines[definedName]['requirements'].indexOf(name) >= 0) {
define.resolve(definedName);
}
}
}
/**
* Require a reference
*
* @param {string} name The absolute name of the reference
* @return {*}
*/
var require = function(name) {
if (define.has(name)) {
return define.get(name);
}
throw new ReferenceError(name + ' is not defined');
}
define.icinga = true;
define.defines = {};
window.define = define;
window.require = require;
})(window);