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Why use MESSAGE in Classes
Posted: Wed Oct 25, 2006 10:00 pm
by Gilbert
Hi All,
Why does certain classes, like TDATABASE, use the syntax:
MESSAGE Delete METHOD _Delete()
why not simply use:
METHOD Delete()
Regards
Gilbert Vaillancourt

Posted: Wed Oct 25, 2006 10:37 pm
by Antonio Linares
Gilbert,
Because Delete() is a reserved function name so it can not be used.
Posted: Thu Oct 26, 2006 2:33 am
by Gilbert
Hi Antonio,
Thanks for your answer. It make sense.
I have another one. I am trying to figure out how does TDATABASE class create the object for each field of a database record. I was looking at the class and could not figure out how it does that. Can you tell me wich portion of code generates the field objects.
Regards

Posted: Thu Oct 26, 2006 6:57 am
by Enrico Maria Giordano
Have a look at OnError() method. By the way, the fields objects are not generated at all.
EMG
Posted: Wed Nov 01, 2006 11:17 pm
by Gilbert
Hi Enrico,
You`re right, tho OnError METHOD handles the fields content to return when an error occurs in the class by doing cString := oDbf:fieldname or
oDbf:fieldname := cString
Doing some test I also figured out than an `_` is passed in front of the fieldname when doing oDbf:filedname := cString, limiting the lenght of the fieldname to 9 positions. Does that mean that the field name of the database must not have more than 9 positions ?
This limitation seems to be only for FiveWin + Clipper. Am I right ?
Regards
Posted: Thu Nov 02, 2006 7:54 am
by Antonio Linares
Gilbert,
Yes, it is a Clipper limitation. With Harbour there is no such limitation.
Posted: Tue Nov 07, 2006 8:56 pm
by Gilbert
Hi Antonio,
Thanks
I would like to know what possibility I have to implement an idea of mine.
The OnError METHOD receives an cFieldName an nError parameters. Is nError always the same or could it be different ? Where is nError comes from ?
Regards