Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!sri-unix!stores
From: stores@unix.SRI.COM (Matt Mora)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Checking for field changes
Message-ID: <29463@sri-unix.SRI.COM>
Date: 10 Apr 89 18:26:20 GMT
References: <1100@atux01.UUCP> <89096.04:03:29.AXS101@PSUVM> <1114@atux01.UUCP> <1266@tellab5.tellabs.CHI.IL.US>
Reply-To: stores@unix.sri.com (Matt Mora)
Organization: SRI, Menlo Park, CA.
Lines: 38

In article <1266@tellab5.tellabs.CHI.IL.US> kenk@tellab5.UUCP (Ken Konecki) writes:
>In article <1114@atux01.UUCP> jlc@atux01.UUCP (J. Collymore) writes:
>> HOWEVER, I want to be able to have the field
>>sense either a mouseClick, or KeyClick so that it will be able to tell me when a
>>user has modified (i.e., tampered with a data in that field)!
>>
>>If anyone can tell me how to do this I would REALLY appreciate it.  Thanks
>
>The easiest way to check for field changes is to have a closeField
>handler for the field:
>    on closeField
>	-- Do what you need to do when the field is changed
>    end closeField.
>
There is also a brute force way to do it.  When the field is opened,
copy the field into a buffer. When the card is closed check the
buffer against the field to see if they are equal.

Its ugly but it should work.

On OpenField
 Global FieldBuff
 put field 1 into FieldBuff
end openField

On CloseField
 Global FieldBuff,FieldDirty
 if field 1 is equal to Fieldbuff then
  put false into FieldDirty
 else
  put true into FieldDirty
 end if
End CloseField

-- 
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Matthew Mora
SRI International                            stores@SRI.COM
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