New blob js

You're interested in learning about the new Blob API in JavaScript!

The Blob API is a powerful tool that allows you to create and manipulate binary data in the form of a blob (binary large object). This can be useful for a variety of tasks, such as:

  1. Uploading files: You can create a blob from a file and then upload it to a server using the XMLHttpRequest object or the Fetch API.
  2. Generating images: You can create a blob from an image and then display it in an HTML element.
  3. Working with audio and video: You can create blobs from audio and video files and then manipulate them using JavaScript.

Here are some key features of the Blob API:

  1. Creating a blob: You can create a blob using the Blob() constructor, which takes an array of arrays (where each inner array represents a chunk of data) and an optional type parameter to specify the MIME type of the blob.
  2. Getting the blob's size: You can get the size of a blob using the size property.
  3. Getting the blob's type: You can get the MIME type of a blob using the type property.
  4. Reading and writing blobs: You can read and write blobs using the Blob.prototype.slice() method, which allows you to extract a portion of the blob, and the Blob.prototype.arrayBuffer() method, which allows you to get the blob's contents as an array buffer.

Here's an example of how you might use the Blob API to create a blob from a file:

// Get the file input element
const fileInput = document.getElementById('fileInput');

// Get the file
const file = fileInput.files[0];

// Create a blob from the file
const blob = new Blob([file], { type: file.type });

// Get the blob's size
console.log(blob.size);

// Get the blob's type
console.log(blob.type);

// Read the blob's contents as an array buffer
const arrayBuffer = await blob.arrayBuffer();
console.log(arrayBuffer);

And here's an example of how you might use the Blob API to create a blob from an image:

// Create a canvas element
const canvas = document.createElement('canvas');
canvas.width = 100;
canvas.height = 100;

// Get the canvas's context
const ctx = canvas.getContext('2d');

// Draw an image on the canvas
ctx.drawImage(document.getElementById('image'), 0, 0, 100, 100);

// Create a blob from the canvas's contents
const blob = new Blob([canvas.toBuffer()], { type: 'image/png' });

// Get the blob's size
console.log(blob.size);

// Get the blob's type
console.log(blob.type);

// Read the blob's contents as an array buffer
const arrayBuffer = await blob.arrayBuffer();
console.log(arrayBuffer);