ToscaWidgets FAQ

General Questions

Why use a Widget? My js/css code is so site specific I can’t see how widgets could help.

Widgets provide reuseablity to your js and css components. ToscaWidgets also allow you to share your widgets in an open community. The ToscaWidgets package provides you with a paster template to help you get started quickly with your own widget library.

OK, why ToscaWidgets then, aren’t TG Widgets the same?

ToscaWidgets have a much more portable api, and can be used in any WSGI app. This portability makes it possible to move your “view” related code between TG1, TG2, Pylons, CherryPy, even Grok. There are also some api differences between TG widgets, and ToscaWidgets, most notably that all ToscaWidgets are ListWidgets, and therefore if you have a widget with children, you do not have to explicitly extend ListWidget like you do in TG. Lastly, TGWidgets are going to be phased out for TG2, so there will no TGWidget support in TG2.

I have a great widget, how do I share it with the community?

Right now there is a library called twtools served at http://twtools.googlecode.com. Your best bet is to find a library in twtools which matches your implementation (jquery widgets go in tw.jquery) or if your widget is a one off, create your own tw package and submit it to twtools. In the near future there will be support at www.toscawidgets.org for widget submission.

ToscaWidgets seems to be lacking in Documentation. How can I validate its use? Is there a good level of support for this project?

There is currently a ground-roots effort from leading TG developers to get the Docs up to snuff. It is our hope that this question will disappear from the FAQ by Q2 2008. The fact is that there is a lot of complexity to capture about how TW works, and much of that information is stored as doc strings in the code. If you check beta.toscawidgets.org you will see a reasonable amount of auto-created docs from those strings. Other ways you can learn more about TW is to dig into the source code, which is reasonably annotated. It is recommended that you read up on Metaclasses in python first. There is also a message board at http://groups.google.com/group/toscawidgets-discuss where you can always ask a question. The board is fairly active, and our developers have been trying to fill out the documentation after a question has been asked. In short, we are working on it.

All Frameworks

No local packages or download links found for RuleDispatch>=0.5a0.dev-r2306 error: Could not find suitable distribution for Requirement.parse(‘RuleDispatch>=0.5a0.dev-r2306’) ~or~ DistributionNotFound: RuleDispatch>=0.5a0.dev-r2247

This is because RuleDispatch has not released a new version, despite having made patches necessary for ToscaWidgets to work.

Generally you can resolve this problem by downloading the rule-dispatch egg directly, like this:

easy_install http://dbsprockets.googlecode.com/files/RuleDispatch-0.5a0.dev-r2306.tar.gz

Usually this is followed by the PyProtocols error: No local packages or download links found for PyProtocols==1.0a0dev-r2302 error: Could not find suitable distribution for Requirement.parse(‘PyProtocols==1.0a0dev-r2302’) ~or~ DistributionNotFound: PyProtocols>=1.0a0dev-r2302

Again, this can be downloaded and installed like this:

easy_install http://dbsprockets.googlecode.com/files/PyProtocols-1.0a0dev-r2302.zip

TG1.0 Specifically

TypeError: No object (name: ToscaWidgets per-request storage) has been registered for this thread

Try this:

easy_install -U toscawidgets

After, make sure ToscaWidgets is turned ON by adding / changing this line in the dev.cfg/prod.cfg or app.cfg:

toscawidgets.on = True

ValueError: need more than 2 values to unpack

Try this:

Just to make sure you have the latest version of Genshi, do this:

easy_install -U genshi

After, make sure Genshi is set as the default view by adding / changing this line in the dev.cfg/prod.cfg or app.cfg:

tg.defaultview = 'genshi'

Compatibility Issues

Grok

If you are going to use ToscaWidgets in a Grok application, you can as long as your Grok app is a WSGI app. Grok has a way of doing this

Then, you need to modify your grok.ini to include the ToscaWidgets middleware:

add:

[filter:tosca]
use=egg:toscawidgets#middleware
default_view=genshi

modify:

[pipeline:main]
pipeline = egg:Paste#cgitb
           egg:Paste#httpexceptions
           suppressZopeErrorHandling
           tosca
           bbb