Perl - Spreadsheet::WriteExcel function explanation - perl

Question

I'd like to use the function "autofit_columns" as found here:CPAN
Here's my program so far(I skipped the DB connect and query part)
my $workbook = Spreadsheet::WriteExcel->new("TEST.xls");
my $bold = $workbook->add_format();
$bold->set_bold();
my $number = $workbook->add_format();
$number->set_num_format(0x01);
$worksheet = $workbook->add_worksheet('Sheet1');
my #headings = ('Blabla...');
foreach $i (#headings){
$worksheet->write(0, $col++, $i, $bold);
};
$col=0;
$lrow=1;
while (#row = $sth->fetchrow_array()) {
$worksheet->write($lrow,$col,\#row);
$lrow++;
};
$sth->finish;
$dbh->disconnect;
autofit_columns($worksheet);
$workbook->close();
sub autofit_columns {
my $worksheet = shift;
my $col = 0;
for my $width (#{$worksheet->{__col_widths}}) {
$worksheet->set_column($col, $col, $width) if $width;
$col++;
}
}
PROBLEM: My columns are not autofitted in the xls file... Any idea why?
I don't get the peice of code:
for my $width (#{$worksheet->{__col_widths}}) {
$worksheet->set_column($col, $col, $width) if $width;
$col++;
}

Answer 1

You need to look at that example again and implement add_write_handler part too before you write anything to your worksheet.
Please take a look at
$worksheet->add_write_handler(qr[\w], \&store_string_widths);
line and then at store_string_widths subroutine implementation.
Answer is that you need to store absolute width of the string at each write. Then, after you wrote all data to your worksheet, you need to walk through rows and find the biggest string's 'length' for each column - that would be desired column width.
Wish you luck.

Answer 2

You are missing the part of the example code that adds the callback function:
$worksheet->add_write_handler(qr[\w], \&store_string_widths);
You are also missing the store_string_widths() function.
In relation to your second question, the callback stores the maximum string length used for each column. The code snippet is using these lengths to set the column width for each column from the first to the last column that has a length stored. If a column hasn't an autfit width stored then its width isn't adjusted.
This is all a little hacky in Spreadsheet::WriteExcel. It will be more integrated into the module in Excel::Writer::XLSX which is the replacement for WriteExcel.