Files
MapLibreParticleLab/platform/node/index.js

58 lines
2.0 KiB
JavaScript

"use strict";
// Shim to wrap req.respond while preserving callback-passing API
var mbgl = require('../../lib/node-v' + process.versions.modules + '/mbgl');
var constructor = mbgl.Map.prototype.constructor;
var Map = function(options) {
if (options && !(options instanceof Object)) {
throw TypeError("Requires an options object as first argument");
}
if (options && options.hasOwnProperty('request') && !(options.request instanceof Function)) {
throw TypeError("Options object 'request' property must be a function");
}
if (options && options.request) {
var request = options.request;
return new constructor(Object.assign(options, {
request: function(req) {
// Protect against `request` implementations that call the callback synchronously,
// call it multiple times, or throw exceptions.
// http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony
var responded = false;
var callback = function() {
var args = arguments;
if (!responded) {
responded = true;
process.nextTick(function() {
req.respond.apply(req, args);
});
} else {
console.warn('request function responded multiple times; it should call the callback only once');
}
};
try {
request(req, callback);
} catch (e) {
console.warn('request function threw an exception; it should call the callback with an error instead');
callback(e);
}
}
}));
} else if (options) {
return new constructor(options);
} else {
return new constructor();
}
};
Map.prototype = mbgl.Map.prototype;
Map.prototype.constructor = Map;
module.exports = Object.assign(mbgl, { Map: Map });