I am maintaining a system which has been written by several prople over several years.  A few days ago I needed to modify a routine which set global variables for each of about 40 columns in a record (so context could be switched and still access those fields).  I needed to add about 15 more columns, and that sort of repetitive work doesn't appeal to me.  Thus I came up with the following:

 

Evaluate(

"Let([" & Let(q=Get(LayoutTableName);ExecuteSQL("
select '$$'||fieldname||'="&q&"::'||fieldname
from filemaker_fields where tablename = '"&q&"'
and fieldclass = 'Normal' and fieldtype not like 'global%'
order by fieldname
";"";";¶";""))&"];0)")

 

Assigning this to a variable resluts in zero, but assigns a (global) variable for each non-null normal field in the current record.

 

I don't know how much use this will be to anyone, but it seemed interesting enough to share.

A couple of thoughts:

 

- that calc is very hard to read.  I would expect a good demo to clearly explain what is happening and why.  There are no comments and no whitespace to follow the calc.  After running this through http://www.aptworks.com/cgi-bin/calc_formatter.cgi

I get this, and it is only marginally more readable

 

Evaluate(

    "Let([" &

    Let(

        q = Get( LayoutTableName );

        ExecuteSQL(

            "

select '$$'||fieldname||'=" & q &

            "::'||fieldname

from filemaker_fields where tablename = '" & q &

            "'

and fieldclass = 'Normal' and fieldtype not like 'global%'

order by fieldname

";

            "";

            ";¶";

            ""

        )

    ) & "];0)"

)

 

- more importantly: why would you want to declare x number of global variables in a calc?  Why not do this in a loop in a script and make local variables and take advantage of the proper scope: http://www.soliantconsulting.com/blog/2014/01/all-variables-should-be-global-or-not

Whatever you do with these variables, now you have to find an equally "fell swoop" method of clearing them out.  So the part that I am missing is: why do you need this, and how do you clean up when you are done?

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This topic has been moved from "Articles, Tips, Techniques & Solutions" to "Calculation Engine (Define Fields)".