loopback-component-storage/lib/storage-handler.js

108 lines
3.0 KiB
JavaScript

var IncomingForm = require('formidable');
var StringDecoder = require('string_decoder').StringDecoder;
/**
* Handle multipart/form-data upload to the storage service
* @param provider The storage service provider
* @param req The HTTP request
* @param res The HTTP response
* @param cb The callback
*/
exports.upload = function (provider, req, res, cb) {
var form = new IncomingForm(this.options);
var container = req.params.container;
var fields = {}, files = {};
form.handlePart = function (part) {
var self = this;
if (part.filename === undefined) {
var value = ''
, decoder = new StringDecoder(this.encoding);
part.on('data', function (buffer) {
self._fieldsSize += buffer.length;
if (self._fieldsSize > self.maxFieldsSize) {
self._error(new Error('maxFieldsSize exceeded, received ' + self._fieldsSize + ' bytes of field data'));
return;
}
value += decoder.write(buffer);
});
part.on('end', function () {
var values = fields[part.name];
if(values === undefined) {
values = [value];
fields[part.name] = values;
} else {
values.push(value);
}
self.emit('field', part.name, value);
});
return;
}
this._flushing++;
var file = {
container: container,
name: part.filename,
type: part.mime
};
self.emit('fileBegin', part.name, file);
var writer = provider.upload({container: container, remote: part.filename});
part.on('data', function (buffer) {
self.pause();
writer.write(buffer, function () {
self.resume();
});
});
part.on('end', function () {
writer.end(function () {
self._flushing--;
var values = files[part.name];
if(values === undefined) {
values = [file];
files[part.name] = values;
} else {
values.push(file);
}
self.emit('file', part.name, file);
self._maybeEnd();
});
});
};
form.parse(req, function (err, _fields, _files) {
cb && cb(err, {files: files, fields: fields});
});
}
/**
* Handle download from a container/file
* @param provider The storage service provider
* @param req The HTTP request
* @param res The HTTP response
* @param cb The callback
*/
exports.download = function(provider, req, res, cb) {
var reader = provider.download({
container: req.params.container,
remote: req.params.file
});
reader.pipe(res);
reader.on('error', function(err) {
cb && cb(err);
});
reader.on('end', function(err, result) {
cb && cb(err, result);
});
}