HTML5 FileAPI implemented in Node.js
The goal here is to be able to use this in connection with jsdom
to create test utilities,
possibly scraping utilities, ultimately an API-driven browser written in Node.
Install:
npm install file-api
Use:
var FileAPI = require('file-api')
, File = FileAPI.File
, FileList = FileAPI.FileList
, FileReader = FileAPI.FileReader
;
Since HTML5 FileAPI
has been described by the W3C (terse, technical) and Mozilla Developer Center (understandable, end-user-oriented) in detail, I'll just highlight the differences:
File
is not (yet) a subclass of Blob
FileError
and FileException
are not yet implemented (they use Error
instead)blob: scheme
and remote URI schemes
are not yet implementedHas the special method setNodeChunkedEncoding()
In the browser, File
has no constructor. In Node, it does.
node-mime
is used for extension-based automatic ContentType
detection (uses name
if available, or path
if not)
File(StringUriPath)
var file = new File("./files/myfile.txt");
File({ buffer: Node.Buffer })
var file = new File({
name: "abc-song.txt", // required
type: "text/plain", // optional
buffer: new Buffer("abcdefg,hijklmnop, qrs, tuv, double-u, x, y and z")
});
File({ stream: Node.ReadStream })
var file = new File({
name: "abc-song.txt", // required
type: "text/plain", // optional
stream: new EventEmitter() // a read stream (emits `error`, `data`, `end`)
});
process.nextTick(function () {
file.stream.emit('data', "abcdefg,hijklmnop, qrs, tuv, double-u, x, y and z");
file.stream.emit('end');
});
File(Object)
var file = new File({
path: "./files/myfile.txt", // path of file to read
buffer: Node.Buffer, // use this Buffer instead of reading file
stream: Node.ReadStream, // use this ReadStream instead of reading file
name: "SomeAwesomeFile.txt", // optional when using `path`
// must be supplied when using `Node.Buffer` or `Node.ReadStream`
type: "text/plain", // generated based on the extension of `name` or `path`
jsdom: true, // be DoM-like and immediately get `size` and `lastModifiedDate`
// [default: false]
async: true, // use `fs.stat` instead of `fs.statSync` for getting
// the `jsdom` info
// [default: false]
lastModifiedDate: fileStat.mtime.toISOString(),
size: fileStat.size || Buffer.length
);
FileReader.setNodeChunkedEncoding() is a non-standard method which hints that the FileReader
should chunk if possible
I.E. The file will be sent with the header Transfer-Encoding: chunked
The default is false
since many webservers do not correctly implement the standard correctly,
and hence do not expect or accept Transfer-Encoding: chunked
from clients.
FileReader.on is a non-standard alias of addEventListener
EventTarget.target.nodeBufferResult is a non-standard property which is a Node.Buffer
instance of the data.
FileReader.on('data', fn) is a non-standard event which passes a Node.Buffer
chunk each time the progress
event is fired.
var fileReader = new FileReader();
fileReader.setNodeChunkedEncoding(true || false);
fileReader.readAsDataURL(new File('./files/my-file.txt'));
// non-standard alias of `addEventListener` listening to non-standard `data` event
fileReader.on('data', function (data) {
console.log("chunkSize:", data.length);
});
// `onload` as listener
fileReader.addEventListener('load', function (ev) {
console.log("dataUrlSize:", ev.target.result.length);
});
// `onloadend` as property
fileReader.onloadend', function () {
console.log("Success");
});
The browser has no constructor for this. Node has two.
new FileList(f1, f2, ...)
var fileList = new FileList(file1, file2, file3);
new FileList([f1, f2])
var files = [
new File('./files/blob.bin'),
new File('./files/image.jpg'),
new File('./files/readme.txt')
],
fileList;
fileList = new FileList(files);
W3C
Mozilla Developer Center:
//
// TODO
//
// HTML5 File URI should be implemented
// will need non-ahr 301-handling requester not prevent circular dep
//
// File should be a subclass of Blob
//
// jsdom EventTarget // http://aptana.com/reference/html/api/EventTarget.html
// target.result
//
// jsdom ProgressEvent // http://www.w3.org/TR/progress-events/
// lengthComputable
// loaded
// total
// initProgressEvent