Macro & OOP syntax

[hua]

I find the following work as expected (just an illustration),

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aOrders := {}
for i := 1 to 7
     cCnt := ltrim(str(i))
     aadd(aOrders, oDbf:order&cCnt)
next

Where in the end, aOrders would contain the value of oDbf:order1, oDbf:order2, oDbf:order3,....oDbf:order7. What annoys me is the reverse isn't true. That is, the following won't work.

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for i := 1 to 7
     cCnt := ltrim(str(i))
     oDbf:order&cCnt := aOrders[i]
next

The values just seem can't be assigned to the database object. Can anyone shed a light on why it's so and a workaround? I'm hoping to avoid having to code it line by line as such

Code: Select all

oDbf:order1 := aOrders[1]
oDbf:order2 := aOrders[2]
oDbf:order3 := aOrders[3]
                .
                .
                .
oDbf:order7 := aOrders[7]

[xProgrammer]

My guess would be (based on dim recollections of my C coding days) that the right hand side of the := is evaluated and the left hand side is taken to be in effect the storage location to which the result of that evaluation is stored. So the &cCnt isn't valid on the left hand side of the :=.

One possible workaround would be to use a combination of FieldPos() and FieldPut() in a method inside a method of CLASS Dbf.

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FOR i := 1 to 7
   cCnt := ltrim( str( i ) )
   oDbf:AssignOrder( order&cCnt, aOrders[i] )
NEXT

and inside CLASS Dbf

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METHOD AssignOrder (pName, pValue ) CLASS Dbf
   FieldPut( FieldPos( pName ), pValue )
RETURN nil

That assumes that you want to put the values directly into the (one) table.

I don't know enough about what you are really trying to do to be of more help, but personally I avoid using &. Why can't class Dbf use an array? Or should you have a sub-table? I'm only guessing, but maybe there's a more elegant solution waiting to be found.

Regards
xProgrammer

[Antonio Linares]

Hua,

Do it this way:

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for i := 1 to 7 
     cCnt := ltrim(str(i)) 
     OSend( oDbf, "_order" + cCnt, aOrders[i] ) 
next

[hua]

One possible workaround would be to use a combination of FieldPos() and FieldPut() in a method inside a method of CLASS Dbf.

Thanks for the reply Doug Yes, that's a valid suggestion but if I'm not mistaken, fieldpos() and fieldput() will read from the physical dbf. I'm trying to optimize the operations as everything is already in an array

I don't know enough about what you are really trying to do to be of more help, but personally I avoid using &.

I'm in the midst of converting an old dos module to windows. I do avoid '&' like a plague but sometimes if I don't see any alternative I'll end up using it anyway.

Why can't class Dbf use an array? Or should you have a sub-table? I'm only guessing, but maybe there's a more elegant solution waiting to be found.

Oh it does. The database class that comes with fivewin stores all the field values in oDbf:aBuffers though we access it in the form of oDbf:<fieldname>. This table should've been further normalized as the customers contact details and their orders are currently kept in the same table but for backward-compatibility sake I just maintain the structure as it is.

Here's to hoping to find an elegant solution

[hua]

Do it this way:

Code: Select all

for i := 1 to 7 
     cCnt := ltrim(str(i)) 
     OSend( oDbf, "_order" + cCnt, aOrders[i] ) 
next

Yes! That's it!. Thank you Antonio!