Add method to webdesign to django.contrib.webdesign package

[martinbean]

The django.contrib.webdesign package currently only has one method for generating place-holder text. Proposing an additional method to generate place-holder images, utilising ​http://placehold.it/.

[Keryn Knight <django@…>]

I respectfully disagree, for the following reasons:

• It leverages an external service API, which has no guarantee of longevity or forward-support. This is the big problem with such a suggestion, as it means all versions would be prone to breaking at the whim of someone else (whether that is the domain owner not continuing to renew the domain, the service being rejigged, the API changing, or an ISP or firewall blocking access to it, etc.)
• With the exception of ImageFields (depending on PIL), Django is mostly not opinionated about images, to the point that there are multiple, varying implementations for things as "simple" as thumbnails.
• with those in mind, I can't see a simple, flexible solution that wouldn't require another configuration setting, which is not ideal for what is ultimately a trivial addition.

[Gabriel Hurley]

While I can certainly understand the argument, I'll second the reliance on external services. Even if we provided a whole host of options (via setting, or an argument to the tag, or anything else) it would have to be maintained, updated, etc. This is particularly negative given that a service could become defunct at any time, leaving that release permanently containing a bad provider. Avoiding that would require a new setting that took a URL parameter, and at that point you've gained very little.

There are already several 3rd-party packages that provide this type of functionality (sorl thumbnail being an example off the top of my head). For the time being I would recommend that we leave it to the community. Thank you for the suggestion, however. The webdesign package is rather anemic.