CODEWITHSUNDEEP
hpcc-ecl
JCW
JCW

Reputation: 222

Using #EXPAND in a record structure

I have a functionmacro and want to specify the name of a field in the dataset that is returned. I thought I could use #EXPAND and supply a string but when I do that I get an error saying it's an 'unknown identifier'. Here's the start of my functionmacro:

CreateDelta(CurrentDataset, PreviousDataset, ComparisonFields = '', DeltaField = 'delta_value') := FUNCTIONMACRO
  InputLayout := RECORDOF(CurrentDataset);
  OutputLayout := RECORD
    // STRING1 delta_value;
    STRING1 #EXPAND(DeltaField);
    InputLayout;
  END;

I would have expected the #EXPAND to make the effective ECL like the commented-out line but that doesn't happen, why not and what's the right way to do this?

Upvotes: 0

Views: 20

Answers (1)

Bob Foreman
Bob Foreman

Reputation: 254

I think you are looking for #TEXT instead of #EXPAND. As in #TEXT(DeltaField).

Here is an example where I am using it:

  FM_Field_Population(infile,infield,compareval) := FUNCTIONMACRO
  c1 := COUNT(infile(infield=compareval));
  c2 := COUNT(infile);
  RETURN DATASET([{'Total Records',c2},
                  {'Recs=' + #TEXT(compareval),c1},
                  {'Population Pct',(INTEGER)((c1/c2)* 100.0)}],
                 {STRING15 valuetype,INTEGER val});
ENDMACRO;

GenRec := RECORD
 STRING1 Gender;
END;

ds1 := DATASET([{'M'},{'M'},{'M'},{''},{''},{'M'},{''},{'M'},{'M'},{''}],GenRec);
ds2 := DATASET([{''},{'M'},{'M'},{'F'},{'F'},{'M'},{''},{''},{'M'},{''}],GenRec);

OUTPUT(FM_Field_Population(ds1,Gender,'M'));
OUTPUT(FM_Field_Population(ds2,Gender,'F'));

Upvotes: 0

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