Spot any errors? let me know, but Unleash your pedant politely please.

Wednesday, 27 February 2013

Requests revisited.

Further to not so stupid after all, the pain of oauth just keeps giving.  I basically got a bunch of stuff working with Requests that was previously working with the old libraries, but in a simpler way.  On that foundation, I tried to once again upload a file to Project Place.

No joy. The request was badly signed. Same problem as before.

I Googled. I searched the Requests issues log etc, but there wasn't much information.

So I contacted the developer at Project Place to explain my problem.  The initial response was the same as before, that I only need to sign the headers, not the body of the HTTP request.   The problem remained that I wasn't in control of that stuff. I was using a library to do it all for me.  I could get an Oauth object by supplying some parameters to something I didn't fully understand and I could send a (GET) request by a url and supplying a nice dictionary of parameters to something else I didn't fully understand.

Jon at Project Place then very kindly sent me some client code that used the Request library to upload a file successfully to Project Place. Now that I had some working code in front of me, I could try to figure it out and then try to figure out where Requests was going wrong. I could see how Jon's code signed the request headers before adding the body - there's no way to specify this in Requests.  I found the Requests code that does the signing. Now one of the issues made a bit more sense. I took a local copy and did a little tweaking, and things seemed to be much better.

While it works, it's not really the correct fix. The problem is (apparently) in requests-oauthlib, but I don't have the knowledge required to fix it.

I didn't think a local copy of Requests was really a long term solution, so today I started to refactor in order to use Jon's code.  It took a while to get anything working at all due Jon's code's handling of parameters: it doesn't (at least not for GET or PUT).  Fortunately he'd commented really well, and once I'd RTFMed, I could see I needed to first add them to the URL - the kind of inconvenience I was hoping to avoid by using Requests.

WAY too much effort went into this line:

url = unicode('%s?%s'%(request,urlencode(params)))

It appears to be working now, with a standard Requests library, plus Jon's code.  It's a just a lot more untidy than I'd hoped for :(

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