>> Note that any callable parameters that you pass this way are >> automatically called (without any additional arguments) - I think that >> was one of your questions. > > That's a pretty horrific design decision. I might have some complex > object that I want to pass in that can be coerced to unicode by Kid > and hence be displayed automatically in a template. Then later I > decide to make it callable (for reasons relevant to its use and > theoretically irrelevant to its presentation) and then who knows what > will happen? If I'm lucky, I get garbage in the HTML output and only > spend an hour or two wondering how this has magically started > happening. If I'm unlucky, that call had side-effects such as altering > my model, which I then have to roll back. > > Even so, this 'feature' is not much use to me, because I need to be > able to pass in a function that takes a single parameter, the idea > being that I call it on each element of my data to get a transformed > copy of the data. But display() will call it for me beforehand, with > no parameters, presumably bombing out with an exception. > > Oh, except it looks like it'll only do that if you pass in the > callable to display(). If it was just a callable in the Widget's > default params list and doesn't appear in the local params argument, > it doesn't look like it gets called whether you wanted it to or not. > > Poor design. I hope the ToscaWidgets people are reading.
I don't agree. The possibility to pass callables that get auto-invoked is very convenient for a great deal of use-cases. Of course one could come up with other approaches - a common subclass these parameters must be inherited from for example. Or some other javaish solution. But for 98% of the use-cases, passing a callable very easily solves the problem. And all you need to circumvene the automatism is a simple lamdba: my_function Additionally, see my other post for a way to create callables for use in the templates. Generally speaking, update_params is *the* central way of performing any needed setup before rendering the template. Diez --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "TurboGears" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/turbogears?hl=en -~----------~----~----~----~------~----~------~--~---
