blob-stream

What is blob-stream?

The blob-stream npm package is used to create a writable stream that generates a Blob. This is particularly useful for generating files in the browser, such as PDFs, images, or any other binary data that can be represented as a Blob.

What are blob-stream's main functionalities?

Creating a Blob from a Stream

This feature allows you to create a Blob from a writable stream. In this example, a PDF document is created using the pdfkit library, and its output is piped to a blob-stream. Once the stream is finished, you can get the Blob and use it as needed, such as creating a URL for download.

const blobStream = require('blob-stream');
const PDFDocument = require('pdfkit');

// Create a document
const doc = new PDFDocument();

// Pipe its output somewhere, like to a blob
const stream = doc.pipe(blobStream());

// Add some content to the document
doc.text('Hello, world!');

// Finalize the PDF and end the stream
doc.end();

// When the stream is finished, get the blob
stream.on('finish', function() {
  // get a blob you can do whatever you like with
  const blob = stream.toBlob('application/pdf');
  const url = stream.toBlobURL('application/pdf');
  console.log(url);
});

Other packages similar to blob-stream

blob-util

The blob-util package provides utilities for working with Blob objects, including creating Blobs from various data types, converting Blobs to other formats, and more. It offers more general-purpose utilities compared to blob-stream, which is specifically focused on creating Blobs from streams.

stream-to-blob

The stream-to-blob package is a simple utility that converts a readable stream into a Blob. It is similar to blob-stream but is more lightweight and focused solely on the conversion process without additional features.

blob-polyfill

The blob-polyfill package provides a polyfill for the Blob constructor, making it possible to use Blob-related functionality in environments where it is not natively supported. While it does not directly compete with blob-stream, it can be used in conjunction to ensure broader compatibility.

README

blob-stream

A Node-style writable stream for HTML5 Blobs, mostly useful in Browserify. Allows you to take the output of any Node stream, and turn it into a Blob or Blob URL for opening in the browser, uploading to a server, etc.

If you don't want to use Browserify, you can also download a prebuilt version of the library.

Example

var blobStream = require('blob-stream');

someStream
  .pipe(blobStream())
  .on('finish', function() {
    // get a blob
    var blob = this.toBlob();
    
    // or get a blob URL
    var url = this.toBlobURL();
    window.open(url);
  });

License

MIT