[SQLObject] Re: trapping sets and gets in SQLObject

[Ian B. <ia...@co...>]

On Nov 20, 2003, at 1:02 PM, Aaron Swartz wrote:
> I'm working on a toolkit for building database-backed websites using 
> SQLObject. One of the things I want to do is support static rendering, 
> so rendered pages could be stored on disk as HTML files and served up 
> normally until they were changed. I want to do this by trapping all 
> sets and gets in SQLObject:
>
> When a page gets rendered it notes down every get the page makes and 
> stores that info away. Then, when another page makes a set it sees if 
> that set affects any rendered pages and, if so, re-renders them.
>
> Anyway, I see you can trap the setters and getters for attributes 
> pretty easily but I was wondering if there was a way to tap into all 
> database sets and gets. (If nothing else, I guess I can just create an 
> SQLObject subclass with a nosy getattr and setattr.)

If you want to trap sets you can override, I think, _SO_setValue() and 
set() -- all database sets go through one or the other -- maybe 
sometimes both if you override a _set_ method, but I'm not sure if I 
changed that or not.

For gets it's a little more complicated, but maybe that's not 
necessary.  An instance can be initialized with column values several 
ways.  I think _SO_selectInit should catch most of them, and maybe 
there's a _SO_getValue for when you have _cacheValues = False.

You can also fiddle with the makeProperties function, which catches all 
the getters and setters.  __getattr__ and __setattr__ won't work for 
you, but __getattribute__ and __setattribute__ will, if you want to be 
particularly general about setters.

--
Ian Bicking | ia...@co... | http://blog.ianbicking.org