03. XMLHttpRequestのPromise化XMLHttpRequestfunction reqListener () { console.log(this.responseText); } var xhr = new XMLHttpRequest(); xhr.addEventListener("load", reqListener); xhr.open("GET", "https://swapi.co/api/people/1"); xhr.send();
参考https://developer.mozilla.org/ja/docs/Web/API/XMLHttpRequest XMLHttpRequestのPromise化function get(url) { // Return a new promise. return new Promise(function(resolve, reject) { // Do the usual XHR stuff var req = new XMLHttpRequest(); req.open('GET', url); req.onload = function() { // This is called even on 404 etc // so check the status if (req.status == 200) { // Resolve the promise with the response text resolve(req.response); } else { // Otherwise reject with the status text // which will hopefully be a meaningful error reject(Error(req.statusText)); } }; // Handle network errors req.onerror = function() { reject(Error("Network Error")); }; // Make the request req.send(); }); } get("https://swapi.co/api/people/1").then(function(response) { console.log("Success!", response); }, function(error) { console.error("Failed!", error); })
get("https://swapi.co/api/people/1").then(function(response) { return JSON.parse(response); }, function(error) { console.error("Failed!", error); }) .then(function(response) { console.log("Yey JSON!", response); }) 参考参考 fs.readFile()のPromise化https://stackoverflow.com/questions/41203409/reading-file-with-es6-promises/41203531 |
|