Forms and Form Data

Prebuilding Form Elements

• The Perl "print" command dumps the output (simply a string of characters) of a given CGI form method to output. This same string can be captured to a Perl string scalar for later use or manipulation if desired.
• For example, the two constructs shown accomplish exactly the same thing:
  

      # Print Three Lines of Text
      print $query->h1("A header line");
      print $query->h1("A Second header line");
      print $query->h1("A Third header line");
  
      # Same thing, different way.
      $outputString = $query->h1("A header line");
      $outputString += $query->h1("A Second header line");
      $outputString += $query->h1("A Third header line");
      print $outputString;
  

• Also, you can prebuild arguments to other CGI methods. This is very helpfull for highly complicated tasks like tables of form fields.
• Anywhere you see the "{}" notation, this is actually a reference to a hash, so you can predefine a hash and pass a reference to it.
• For example, the two constructs shown accomplish exactly the same thing:
  

  print "Below should be a left justified image\n";
  print $query->hr();
  print $query->img({-src=>'/killbill/images/xmms.jpg',
  	           -align=>'left',
  	           -width=>'275',
  	           -height=>'116'});
  
  print "Same image, generated differently\n";
  print $query->hr();
  my %myHash = ( -src=>'/killbill/images/xmms.jpg',
  	       -align=>'left', -width=>'275', -height=>'116' );
  print $query->img(\%myHash);
  

• Anywhere you see the "[]" notation, this is actually a reference to an array, so you can predefine an array and pass a reference to it.
• For example, the two constructs shown accomplish exactly the same thing:
  

  # Try an unorderd list
  print $query->hr();
  print "This should be a centered unordered list of three elements\n";
  print $query->ul({-align=>'center'}, 
  		 $query->li({-type=>'disc'},
  			    ['List Entry One',
  			     'List Entry Two', 
  			     'List Entry Three']));
  print $query->hr();
  
  # same thing, different way
  print "This should be a centered unordered list of three elements\n";
  my @listArray = ('List Entry One', 'List Entry Two',  'List Entry Three');
  print $query->ul({-align=>'center'}, 
  		 $query->li({-type=>'disc'},
  			    \@listArray));
  print $query->hr();