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How to check for an array's existance.
Usefull Functions & Procedures
In my Foxpro Advisor article (subscription required): http://my.advisor.com/doc/17117
I argued that this line of code:
is not as readable, maintainable or extendable as:
Remember, copying code is not code reuse!
The following code originated with me and was donated to the FoxPro community by Russ Swall President of VisionPace in memory of Drew Speedie.
I argued that this line of code:
Code:
IF TYPE("ALEN(m.SomeVariable")
Code:
IF X2IsArray(@m.SomeVariable)Remember, copying code is not code reuse!
The following code originated with me and was donated to the FoxPro community by Russ Swall President of VisionPace in memory of Drew Speedie.
Code:
*
* X2IsArray.PRG
* RETURNs a logical value indicating whether the
* variable PASSED BY REFERENCE or the passed Object.Property
* is an array.
*
* Copyright (c) 2004-2005 Visionpace All Rights Reserved
* 17501 East 40 Hwy., Suite 218
* Independence, MO 64055
* 816-350-7900
* http://www.visionpace.com
* http://vmpdiscussion.visionpace.com
* Author: Drew Speedie
* Special thanks to Mike Yearwood and Chris Bohling
*
* USAGE
* =====================================
* IF X2IsArray(@m.SomeVariable)
* ...
* ENDIF
* IF X2IsArray(SomeObject,"SomeProperty")
* ...
* ENDIF
*
*
* lParameters
* tuVariable (R) Memory variable to be checked,
* passed here BY REFERENCE
* -OR-
* Object whose tcProperty is to be
* checked
* tcProperty (O) If tuVariable is passed as an object
* reference, this parameter is REQUIRED,
* and indicates the property of the
* tuVariable object that is checked for
* being an array
* If tuVariable is passed as a memory
* variable, DO NOT PASS THIS PARAMETER,
* or this routine will RETURN .F.
*
LPARAMETERS tuVariable, tcProperty
LOCAL llRetVal
DO CASE
******************************************************
CASE PCOUNT() = 1 AND NOT VARTYPE(m.tuVariable) = "O"
******************************************************
llRetVal = TYPE("ALEN(m.tuVariable)") = "N"
******************************************************
CASE PCOUNT() = 1 AND TYPE("ALEN(m.tuVariable)") = "N"
******************************************************
llRetVal = .t.
******************************************************
CASE VARTYPE(m.tuVariable) = "O" ;
AND VARTYPE(m.tcProperty) = "C" ;
AND NOT EMPTY(m.tcProperty)
******************************************************
llRetVal = TYPE("ALEN(m.tuVariable." + m.tcProperty + ")") = "N"
******************************************************
OTHERWISE
******************************************************
*
* you apparently haven't passed the parameters
* properly -- we could have RETURNed .NULL. here,
* but then every time you call X2IsArray(), you
* would have to check for .NULL, .T., and .F.
* rather than just .T. or .F., so it's up to you
* to pass the parameters correctly
* Roses are red
* Violets are blue
* To pass parms correctly
* Is all up to you
*
llRetVal = .f.
ENDCASE
RETURN m.llRetVal