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Place of DODEFAULT()
Message
Information générale
Forum:
Visual FoxPro
Catégorie:
Autre
Versions des environnements
Visual FoxPro:
VFP 9 SP2
OS:
Windows Server 2012
Network:
Windows 2008 Server
Database:
MS SQL Server
Application:
Web
Divers
Thread ID:
01605192
Message ID:
01605202
Vues:
48
>>>>>I have a control class bases on the container. The hierarchy of the classes is as following:
>>>>>Container - VFP class
>>>>>MyBaseClass - based on VFP Container
>>>>>MySpecificClass - based on MyBaseClass
>>>>>
>>>>>Now I need to change the size of the MySpecificClass (bases on some semaphore flag) so that this MySpecificClass is wider and the textbox inside of this class is wider. So I need to add the code to the INIT method of MySpecificClass, something like the following:
>>>>>
>>>>>
>>>>>if file("my_semaphore")
>>>>>   this.width = this.width + 50
>>>>>   this.txt_box.width = this.txt_box.width + 50
>>>>>endif
>>>>>
>>>>>
>>>>>But of course I want the code in the MyBaseClass INIT to be fired. For example, would it correct the following?
>>>>>
>>>>>
>>>>>dodefault()
>>>>>if file("my_semaphore")
>>>>>   this.width = this.width + 50
>>>>>   this.txt_box.width = this.txt_box.width + 50
>>>>>endif
>>>>>
>>>>>
>>>>>And should dodefault() be before or after my "specific" code? Or it does not matter at all?
>>>>>
>>>>>TIA
>>>>
>>>>It depends what you want :-)
>>>>Most of the cases it didn't matter where it is placed,
>>>>but IF you want to cancel the INIT and have logic for this in your base class method you should carefully decide where to place this method:
>>>>Sometimes you need this:
>>>>
>>>>lbReturn = DODEFAULT()
>>>>** "specific" code and maybe change lbReturn
>>>>RETURN lbReturn
>>>>
>>>>
>>>>
>>>>other time you can do this:
>>>>
>>>>** "specific" code
>>>>RETURN DODEFAULT()
>>>>
>>>
>>>Interesting. I have never seen the code "RETURN DODEFAULT()" but it makes sense. My base class has RETURN .F. in its INIT (in case of cancel).
>>>
>>>So now I am wondering, if I were to have the code as I put in my initial example (DODEFAULT() first, and then the custom code) and the code in the DODEFAULT() return .F., would the control still initialize?
>>
>>That's why I usually
>>
>>IF NOT DODEFAULT()
>> RETURN .F.
>>ENDIF
>>
>>before I add custom code.
>
>Makes sense. Thank you.

Sometimes you want default code to be executed after the custom code.
Against Stupidity the Gods themselves Contend in Vain - Johann Christoph Friedrich von Schiller
The only thing normal about database guys is their tables.
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