formstream

A multipart/form-data encoded stream, helper for file upload.

Install

1npm install formstream

Quick Start

1var formstream = require('formstream');
2var http = require('http');
3
4var form = formstream();
5
6// form.file('file', filepath, filename);
7form.file('file', './logo.png', 'upload-logo.png');
8
9// other form fields
10form.field('foo', 'fengmk2').field('love', 'aerdeng');
11
12// even send file content buffer directly
13// form.buffer(name, buffer, filename, mimeType)
14form.buffer('file2', new Buffer('This is file2 content.'), 'foo.txt');
15
16var options = {
17  method: 'POST',
18  host: 'upload.cnodejs.net',
19  path: '/store',
20  headers: form.headers()
21};
22var req = http.request(options, function (res) {
23  console.log('Status: %s', res.statusCode);
24  res.on('data', function (data) {
25    console.log(data.toString());
26  });
27});
28
29form.pipe(req);

Chaining

1var fs = require('fs');
2var formstream = require('formstream');
3
4var filepath = './logo.png';
5fs.stat(filepath, function (err, stat) {
6  formstream()
7    .field('status', 'share picture')
8    .field('access_token', 'your access token')
9    .file('pic', filepath, 'logo.png', stat.size)
10    .pipe(process.stdout); // your request stream
11});

Set min chunk buffer size

Some web servers have a limit on the number of chunks, and you can set minChunkSize to ensure the size of chunk sent to the server.

1var fs = require('fs');
2var FormStream = require('formstream');
3
4var filepath = './big-file.zip';
5fs.stat(filepath, function (err, stat) {
6  new FormStream({
7    // send >= 2MB chunk buffer size to the server
8    minChunkSize: 1024 * 1024 * 2,
9  }).field('status', 'share file')
10    .field('access_token', 'your access token')
11    .file('file', filepath, 'big-file.zip', stat.size)
12    .pipe(process.stdout); // your request stream
13});

API Doc

formstream([options])

Create a form instance.

Arguments

• options.minChunkSize Number - min chunk size to emit data event

Returns

Form - form instance

FormStream#field(name, value)

Add a normal field to the form.

Arguments

• name String - Name of field
• value String - Value of field

Returns

Form - form instance

FormStream#file(name, filepath[, filename][, filesize])

Add a local file to be uploaded to the form.

Arguments

• name String - Name of file field
• filepath String - Local path of the file to be uploaded
• filename String - Optional. Name of the file (will be the base name of filepath if empty)
• filesize Number - Optional. Size of the file (will not generate Content-Length header if not specified)

Returns

Form - form instance

FormStream#buffer(name, buffer, filename[, contentType])

Add a buffer as a file to upload.

Arguments

• name String - Name of field
• buffer Buffer - The buffer to be uploaded
• filename String - The file name that tells the remote server
• contentType String - Optional. Content-Type (aka. MIME Type) of content (will be infered with filename if empty)

Returns

Form - form instance

FormStream#stream(name, stream, filename[, contentType][, size])

Add a readable stream as a file to upload. Event 'error' will be emitted if an error occured.

Arguments

• name String - Name of field
• stream stream.Readable - A readable stream to be piped
• filename String - The file name that tells the remote server
• contentType String - Optional. Content-Type (aka. MIME Type) of content (will be infered with filename if empty)
• size Number - Optional. Size of the stream (will not generate Content-Length header if not specified)

Returns

Form - form instance

FormStream#headers([headers])

Get headers for the request.

Arguments

• headers Object - Additional headers

Example

1var headers = form.headers({
2  'Authorization': 'Bearer kei2akc92jmznvnkeh09sknzdk',
3  'Accept': 'application/vnd.github.v3.full+json'
4});

Returns

Object - Headers to be sent.

Event 'error'

Emitted if there was an error receiving data.

Event 'data'

The 'data' event emits when a Buffer was used.

See Node.js Documentation for more.

Event 'end'

Emitted when the stream has received no more 'data' events will happen.

See Node.js Documentation for more.

License

MIT

Contributors

fengmk2	xingrz	semantic-release-bot	fjc0k	mrspeiser	dead-horse
shaozj

This project follows the git-contributor spec, auto updated at Wed May 15 2024 00:34:12 GMT+0800.