[Gambas-user] gambas and outportb

[Rob Kudla]

On Sat June 24 2006 01:46, Laxminarayan G Kamath A wrote:
> On 06/23/06 13:46, mike webb wrote:
> >writing a program to control our air condition units in our
> > factory. have always used ms-dos and turbo c to control
> > hardware. in this case though, i need to access web pages on
> > the Internet and extract our local temp.
>
> _Bad_ programming practice.. never do this for mission
> critical stuff. what will happen if the page changes a bit for
> some reason and wrong values go in? _HAVOC_ !

No, not havoc... sanity checks followed by error messages as 
appropriate.  I've been scraping Weather Underground for about 4 
years to feed a KDE temperature + heat index/wind chill applet I 
wrote, and the worst it's ever done is give me "--" or "0" 
because it can't parse the data.  

Before that, I wrote a currency converter that used Yahoo Finance 
as a back end (which I'm sure would now either be prevented by a 
CAPTCHA or just against their terms of use), and when they 
changed their format I had it throw an error saying "Yahoo 
Format Error - If this persists, call Rob." It's not like my 
company at the time would have gotten 1 dollar = 0 pounds and 
had all its UK bills go out for infinite amounts.

If there's a better defined source for temperature data local to 
him, he should use it (and I'm sorry if this sounds 
condescending, but.... hello, thermostats are really not that 
expensive), but scraping is a time-honored integration practice 
when you have no control over your source data, and can 
certainly be done right.

Rob