Promises

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volver a M06 Desarrollo web en entorno cliente

Resources

Javascript Promises

Exercises

  1. Make a web page with a button (button text: Load image), when we click on that button you have use "promises" to load an image from your server and catch the errors, if there are
  2. With the given code, create a web page that call a server with some data (it's doesn't matter what data) and print the data on the page applying some kind of format.
    const loadJSON = (file) => {
      return new Promise((resolve, reject) => {
        const xhr = new XMLHttpRequest();
        xhr.open('GET', file, true);
        xhr.responseType = 'json';
        xhr.onload = () => {
          if (xhr.status === 200) {
            resolve(xhr.response);
          } else {
            reject(xhr.statusText);
          }
        };
        xhr.onerror = () => reject(xhr.statusText);
        xhr.send();
      });
    };