Web Plugin Access-Control-Allow-Origin header not present

[andremiller]

I'm putting together a client-side HTML5/Javascript player that uses the Web plugin's REST/JSON API.

Because the source files for the client is not hosted by the flask web server, I'm getting the following error in the browser when I try to make API calls using XMLHttpRequest in Javascript:

XMLHttpRequest cannot load http://beets:8337/item/716. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://musicplayer:9000' is therefore not allowed access.

Is there a way the beets web server can be configured to provide this header so remote browsers can access the API?

PS: I found this link which has an example of how to implement it in Flask: http://flask.pocoo.org/snippets/56/

[andremiller]

Just tested the snippet I refer to above and it works. I placed the whole snippet into a new file called crossdomain.py inside the beetsplug/web directory and then edited beetsplug/web/init.py as such:

Near the top:
from crossdomain import crossdomain

Below each route or pair of routes, added:
@crossdomain(origin='*')

For example:

@app.route('/item/<idlist:ids>')
@crossdomain(origin='*')
@resource('items')
def get_item(id):
    return g.lib.get_item(id)

@app.route('/item/')
@app.route('/item/query/')
@crossdomain(origin='*')
@resource_list('items')
def all_items():
    return g.lib.items()

[sampsyo]

Hi! Awesome; I'm glad you're interested in working on this.

I'm not sure if it's clear from the paper-trail of recent issues, but there is a new effort to start from scratch with the web API. See #738, #718, #1002, and AURA. The AURA reference server has CORS enabled.

So we can add a cross-domain header to the current plugin in the short term (care to open a PR?), but soon we will be throwing this one away and adding a new backend. So if you're building a new frontend, let's stay in touch—it would be great to get compatible with the new backed as quickly as possible.

[andremiller]

Thanks sampsyo. I'll go check out AURA, I didn't know it existed!

I discovered beets about two days ago after getting frustrated with online streaming services and decided to turn my own music collection into something I can stream. It looked perfect but I wanted a better web player, so of course I jumped in and started hacking without looking at all the documentation and current development :).

[sampsyo]

Awesome; I think we have exactly the same goal:

I discovered beets about two days ago after getting frustrated with online streaming services and decided to turn my own music collection into something I can stream.

😃

My ultimate dream with AURA is indeed to have a good, interoperable alternative to streaming services.

[andremiller]

In the meantime I created a pull request. My first one, so I am not sure I did it 100% correct.

[andremiller]

@sampsyo I hacked together a quick example here: https://github.com/andremiller/beets-player-samples/tree/master/w2ui

This still uses the beetsweb plugin and it's quite ugly, more of a proof of concept.

[sampsyo]

Very cool! This looks useful already. I'll totally give it a try.