javascript fetch data from api code example

Example 1: How to Use the JavaScript Fetch API to Get Data

fetch('http://api.steampowered.com/ISteamUserStats/GetGlobalAchievementPercentagesForApp/v0002/?gameid=221380')
    .then(function(response) {
        return response.json();
    })
    .then(function(myJson) {
        console.log(JSON.stringify(myJson));
    });

Example 2: how to use fetch() javascript

//Most API's will only allow you to fetch on their website.
//This means you couldn't run this code in the console on 
// google.com because:
// 		1. Google demands the fetch request be from https
// 		2. open-notify's API blocks the request outside of their website

fetch('http://api.open-notify.org/astros.json')
.then(function(response) {
  return response.json();
})
.then(function(json) {
  console.log(json)
});

// Here is another example. A method (function) that 
// grabs Game of Thrones books from an API ...

function fetchBooks() {
  return fetch('https://anapioficeandfire.com/api/books')
  .then(resp => resp.json())
  .then(json => renderBooks(json));
}

function renderBooks(json) {
  const main = document.querySelector('main')
  json.forEach(book => {
    const h2 = document.createElement('h2')
    h2.innerHTML = `<h2>${book.name}</h2>`
    main.appendChild(h2)
  })
}

document.addEventListener('DOMContentLoaded', function() {
  fetchBooks()
})

Example 3: get data from fetch response html

fetch('/about').then(function (response) {
	// The API call was successful!
	return response.text();
}).then(function (html) {

	// Convert the HTML string into a document object
	var parser = new DOMParser();
	var doc = parser.parseFromString(html, 'text/html');

	// Get the image file
	var img = doc.querySelector('img');
	console.log(img);

}).catch(function (err) {
	// There was an error
	console.warn('Something went wrong.', err);
});

Example 4: fetch get data js

var myHeaders = new Headers();

var myInit = { method: 'GET',
               headers: myHeaders,
               mode: 'cors',
               cache: 'default' };

fetch('flowers.jpg',myInit)
.then(function(response) {
  return response.blob();
})
.then(function(myBlob) {
  var objectURL = URL.createObjectURL(myBlob);
  myImage.src = objectURL;
});