A request body receiver & parser middleware for Koa@2+.

Support body type:

• application/json
• application/x-www-form-urlencoded
• text/plain
• multipart/form-data

// npm
npm install bodyreceiver
// yarn
yarn add bodyreceiver

var Koa = require('koa');
var BodyReceiver = require('bodyreceiver');

var app = new Koa();
var bodyReceiver = new BodyReceiver();

app.use(bodyReceiver.startup());

app.use((ctx, next) => {
	// Received body pass to ctx.request.body
	ctx.body = ctx.request.body;
	return next();
});

app.listen(3000, '127.0.0.1');

• BodyReceiver([options])

BodyReceiver main Class, will return new instance.

var bodyReceiver = new BodyReceiver();

• bodyReceiver.startup()

Register bodyReceiver middleware for Koa.

<!-- Example form html -->
<form action="/file" method="POST" enctype="multipart/form-data">
    <input type="text" name="firstname" />
    <input type="text" name="lastname" />
    <input type="file" name="image" />
    <button>Submit</button>
</form>

// upload file result
console.log(ctx.request.body);

{
    fields: { // other filed
        firstname: 'foo',
        lastname: 'bar',
    },
    files: {
        image: [{
            name: 'b84f4a4a275002d3379c3be782369cff.jpg', // filename
            type: 'image/jpeg', // filetype
            size: 976, // filesize
            contents: <Buffer ...>,  // file contents is Buffer type
            createReadStream: [Function]  // readable Stream
        }]
    }
}

If use FileReader read base64 file in browser, then upload the base64 file, set the content-type header to text/plain.

• accept Regexp / Function, Upload file only, default is null, means accept all file type.

limit accept file type, if accept is Regexp, will test file MIME type, if accept is Function, will invoke function test file type and size.

{
    accept: function (type, size) {
        // must return Boolean result
    }
}

• write Boolean, Upload file only, default is false.

Whether write file to disk, uploaded file contents default is Buffer type, can pass through the Stream transmission.

• maxBodySize String, default is 1mb.

Maximum body size, the value can pass through bytes parse, if body size greater than maxBodySize will emit error event.

• maxFileSize String, Upload file only, default is 3mb.

Maximum uploaded file size, the value can pass through bytes parse, if file size greater than maxFileSize will emit error event.

• minFileSize String, Upload file only, default is null.

Minimum uploaded file size, the value can pass through bytes parse, if file size less than minFileSize will emit error event.

• keepFilename Boolean, Upload file only, default is false.

Whether keep origin file name. If value is false, the BodyReceiver will generate a new hash name by file contents, is value is true, keep origin file name.

• generateFilename Boolean, Upload file only, default is null.

Custom generate file name rules.

{
    generateFilename: function (originName, hashName, extName) {
        // must return a new filename
    }
}

• dest String, Upload file only, default is process.cwd() + '/upload'.

Uploaded file save folder, the dest must coordination write usage, if dest folder is not exists, the BodyReceiver will create a new folder, the new folder permission is 0777.

The BodyReceiver can emit various events.

• error Error event, body parse error, file type or size is invalid, both emit error event.

bodyReceiver.on('error', function (error, ctx) {
    console.error(error);
    ctx.throw(error, 422);
});

• progress Receive file progress event.

• aborted Receive file aborted event.

• data If the file is valid, will emit data event.

• file If the file is write to disk, will emit file event.

• end If the file receive is end, will emit end event.

MIT @ Yiguo Chen