upload.js

request.post(this.props.url)
    .attach('file', file, file.name)
    .on('progress', function(e){
        var elem = {name: file.name, pct: parseInt(e.percent).toString() + '%'};
        var current = this.state.uploading;
        current[file.name] = elem;
        this.setState({ uploading: current });
    }.bind(this))
    .on('error', function(err){
        var current = this.state.uploading;
        current[file.name].pct = 'error uploading :/';
        this.setState({ uploading: current });
    })
    .end(function(res){
        var current = this.state.uploading;
        current[file.name].pct = 'Finished.';
        this.setState({ uploading: current });
        setTimeout(function(){
            delete current[file.name];
            this.setState({ uploading: current });
        }.bind(this), 3500);
    }.bind(this));