adding optional jsonp parameter to events/get_data

[gingerlime]

• using the same code / structure as render

[gingerlime]

I'm trying to use the events/get_data to retrieve event annotation data for giraffe graphite dashboard. It would be useful to be able to pull data using jsonp rather than just plain-json. This is my first graphite pull request, so hope I'm sticking to the coding standards of the project. I'm also not really sure if this pull request should go into 0.9.x or master branch (or both?).

[corywright]

I also would like to see jsonp available where ever json currently is supported.

[drawks]

I couldn't care less about inclusion or not of this feature, but would like to ensure that we take into account the difference in valid characters in the key side of the has between eval-able javascript (required by jsonp) and pure json. Who ever finally commits to implementing this would do good by the project to ensure special case handling for the few characters which are legal in json but aren't in javascript.

This link explains:
http://timelessrepo.com/json-isnt-a-javascript-subset

[gingerlime]

First of all, thanks for the interesting link. I learned something new and quite interesting.

A couple of comments:

• I'm not sure how this pull request makes the situation any different. Perhaps it uses the same implementation as where jsonp is used in render, which means if later this needs to be fixed it would need to be fixed in two places?
• I just did a quick test using the text with the whitespace from the link, and then using the standard json module as well as simplejson (either of those as far as I see are used by graphite in utils). Perhaps I'm wrong, but it looks to me like both these modules handle the conversion correctly already:

Python 2.7.3 (default, Aug  1 2012, 05:14:39) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> s = '{"JSON":"ro
cks!"}'
>>> s
'{"JSON":"ro\xe2\x80\xa8cks!"}'
>>> import json
>>> json.dumps(s)
'"{\\"JSON\\":\\"ro\\u2028cks!\\"}"'
>>> import simplejson
>>> simplejson.dumps(s)
'"{\\"JSON\\":\\"ro\\u2028cks!\\"}"'