Ralph Bean
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This site is deprecated, please visit http://threebean.org/blog/
Updated: 1 hour 21 min ago
My blog is moving…
I won’t be updating this blog anymore – please visit http://threebean.org/blog instead.
This wordpress site will be left in tact however, since there are a number of posts linked to from other sites.
Categories: Code
Hacking tw2 resource injection (in pyramid)
In #toscawidgets this morning, zykes- was asking about how to do the jquery removal hack I wrote about a month back but in Pyramid instead of TurboGears2. First I’ll summarize the problem, then show you our solution.
toscawidgets2 tw2.* provides lots of handy web ui widgets including a wrapper around jquery-ui, jqgrid, and lots of fancy data widgets. One of the problems it solves for you is de-duplicating resources. Say you’re including two fancy jquery-related widgets. Both of them require that jquery.js be included on the page. tw2 includes a piece of middleware that tracks all the resources required by the widgets being rendered on a given request, reduces that list to a set with no duplicates, orders it by dependency, and injects it into the <head> tag.
Usually this is fine, but in some cases you want an exception to the rule. Say, like in my previous post, you want to include jquery.js yourself manually and you’d rather not have tw2 stomping all over your javascript namespace. You could disable tw2 injection of all resources, but you want all the others included — just not jquery.
There is no automatic detection and filtration flag implemented in tw2 and it would be tough to do in the general case. tw2 can’t guarantee that it’s own jquery.js and your jquery.js are the same, or different, or included, or not included, or anything — it doesn’t even try.
To get tw2 to not do what you don’t want, you need to un-register tw2‘s jquery resource from the middleware yourself (on each request). Previously we came up with a working hack that does this in the context of a TurboGears2 app. Here’s the same concept applied to a Pyramid app using a Pyramid “tween”.
import tw2.core.core
import tw2.jquery
def remove_jq_factory(handler, registry):
""" Remove tw2 jquery_js from tw2's middleware registry.
In order to use this, you need to add the following to your
myapp/__init__.py file:
config.add_tween('myapp.tween.remove_jq_factory')
"""
def remove_jq_tween(request):
# Send the request on through to other tweens and to our app
response = handler(request)
# Before the response is modified by the tw2 middleware, let's remove
# jquery_js from its registry.
offending_links = [r.req().link for r in [
tw2.jquery.jquery_js,
]]
local = tw2.core.core.request_local()
local['resources'] = [
r for r in local.get('resources', list())
if r.link not in offending_links
]
return response
return remove_jq_tween
Categories: Code
Announcing — 24 hour tw2 bug sprint for PyCon
(First published to the toscawidgets-discuss google group)
It came up in IRC the other day that tw2 has been through many, many beta iterations. So many in fact, that a full on tw2 2.0 release is painfully overdue.
That said, there are still plenty of out-standing issues in our issue tracker:
http://bitbucket.org/paj/tw2core
Before we tag and name the 2.0 final product, I’m proposing — no, announcing — a 24 hour tw2 sprint the weekend before PyCon. We’ll write docs, we’ll automate tests, we’ll settle the dispatch dispute and wax philosophic.
I invite you to join me Saturday, March 3rd at 18:00:00 UTC through Sunday, March 4th 18:00:00 UTC. Hop into #toscawidgets on freenode or join me in a hangout on google plus. We’ll nail every last bug on deck and still have time for a beer.
Yours in widgetry-
- threebean
Categories: Code
