Using flow.js to upload to Google Cloud Storage? · Issue #170 · flowjs/flow.js (original) (raw)

Hello flow.js developers,

I am currently developing a web application that enables users to upload files, but the requirement is that they be stored on Google Cloud Storage instead of the server providing the application. Handling multiple uploads concurrently is also required.

To reduce bandwidth usage and server loads, Google recommends communicating from the client directly with GCS servers, omitting the server providing the web application. The preferred way for me would be probably either with Signed URLs or Signed Policy Documents, because they do not require logging in with a Google Account https://cloud.google.com/storage/docs/access-control

Providing a test handler and an upload handler is easy when in control of the destination server, but to work with GCS one would need to adjust to their API.

I am thoroughly impressed by how flow.js works when uploading to a server that provides a suitable API and had little success finding any good prefabricated front-end solutions that would work with GCS. I thought that a whole lot of existing flow.js code (and ng-flow, which is equally adorable) could be put to use here, if only the parts involved in POST requests were adjusted.

As to the Google Cloud Storage API, it is a REST interface, is reasonably well documented, supports resumable and chunked uploads.
https://cloud.google.com/storage/docs/json_api/v1/how-tos/upload#resumable

I don't think that it has an equivalent of flow's test handler, but the responses from chunk uploads report of error/success of each chunk's upload.

So here comes my question:
Is it realistically possible to divert the relevant XHR parts of flow.js's code to communicate with Google Cloud Storage's API or do you foresee any design barriers that would make attempts to rewrite it a wasted effort? I have done a preliminary scan of flow's code, but having no prior experience with its inner workings I fear I might miss some crucial and obvious facts.

The biggest advantage of adapting the code of flow.js to this task would be reusing the parts of user interface and ng-flow instead of reinventing the wheel for just communicating with a different API. And that the code is already mature, tested and widely compatible.

I suspect that most of you would have no motivation to implement such functionality right now, so I guess that I could fork and contribute to the project, but I would be really grateful for your expertise and highlighting possible issues with this undertaking.