Body.json()

Body mixin의 json() 매서드는 Response 스트림을 가져와 스트림이 완료될때까지 읽는다. 이 메서드는 body 텍스트를 JSON으로 바꾸는 결과로 해결되는 promise를 반환한다.

response.json().then(function(data) {
  // do something with your data
});

없음.

A promise that resolves with the result of parsing the body text as JSON. This could be anything that can be represented by JSON — an object, an array, a string, a number...

In our fetch json example (run fetch json live), we create a new request using the Request.Request constructor, then use it to fetch a .json file. When the fetch is successful, we read and parse the data using json(), then read values out of the resulting objects as you'd expect and insert them into list items to display our product data.

var myList = document.querySelector('ul');

var myRequest = new Request('products.json');

fetch(myRequest)
  .then(function(response) { return response.json(); })
  .then(function(data) {
    for (var i = 0; i < data.products.length; i++) {
      var listItem = document.createElement('li');
      listItem.innerHTML = '<strong>' + data.products[i].Name + '</strong> can be found in ' +
                           data.products[i].Location +
                           '. Cost: <strong>£' + data.products[i].Price + '</strong>';
      myList.appendChild(listItem);
    }
  });

• ServiceWorker API
• HTTP access control (CORS)
• HTTP