Forms and Form Data

Generating URL's

• Perl constructs are also available for generating URL information in just about any form imaginable.
• The Perl CGI construct to construct a URL is:
  

      # Generate my URL
      print $query->br("My full URL:", $query->url() );
      print $query->br("My relative URL:", $query->url(-relative=>1) );
      print $query->br("My absolute URL:", $query->url(-absolute=>1) );
      print $query->br("My URL with path:", $query->url(-path_info=>1) );
      print $query->br("My URL with path and query info:", 
  		     $query->url(-path_info=>1, -query=>1) );
      print $query->hr();
  

• Perl constructs are also available for generating URL information in just about any form imaginable.
• Because the form that uses the "-query=>1" maintains all the current state information from your CGI object ($query), you can use it in conjunction with the param method to generate custom links with unique states.
• Detailed Annotated Example:
  

  #!/usr/bin/perl -w
  use CGI;
  use strict;
  
  my $query=new CGI;
  
  # Create a header, and let it default arguments, it likely knows
  # better then we do.
  
  print $query->header();  
  
  # Start the body of our document, and give it a title 
  
  print $query->start_html({-title=>'Compuware Perl Class State Example...',
  			  -author=>'Bill Kilgallon'});
  
  my $currentState = $query->param('myState');
  
  # First time in the form, no state value exists
  if ( ! $currentState ) {
  
      # Start the input form
      print $query->startform({-method=>'post'});
  
      # Print Name form field
      print $query->h2("Please enter your Name: ");
      print $query->textfield({-name=>'userName'});
      
      # Print Employee Number form field
      print $query->h2("Please enter your Employee ID Number:");
      print $query->textfield({-name=>'employeeId'});
      print $query->p();
      
      # Create a hidden field that maintains state so we know where we
      # are in the sequence of forms.
      $query->param('myState', 'DoPageTwo');    
      print $query->hidden({-name=>'myState'});
  
      # Submit button
      print $query->submit();
      
      # End the form
      print $query->endform();
  } 
  
  # See if we are in stage two of our form list
  elsif (  $currentState eq 'DoPageTwo' )
  {
      # Start the input form
      print $query->startform({-method=>'post'});
  
      # Print Date form field
      print $query->h2("Please enter Todays Date: ", $query->br());
      print $query->textfield({-name=>'theDate'});
      
      # Create a hidden field that maintains state so we know where we
      # are in the sequence of forms.
      $query->param('myState', 'DoPageThree');    
      print $query->hidden({-name=>'myState'});
  
      # We also need to carry along some other hidden fields, to
      # propagate the info from the first form through this second
      # form, and on to the third form, etc.
      print $query->hidden({-name=>'userName'});
      print $query->hidden({-name=>'employeeId'});
      print $query->hidden({-name=>'theDate'});
  
      # Submit button
      print $query->submit();
      
      # End the form
      print $query->endform();
  }
  
  # See if we are in stage three of our form list
  elsif (  $currentState eq 'DoPageThree' )
  {
      # Continue to carry along necessary hidden fields
      print $query->hidden({-name=>'userName'});
      print $query->hidden({-name=>'employeeId'});
      print $query->hidden({-name=>'theDate'});
  
      print $query->h1("Here are the values you input so far:");
      print $query->p($query->em("userName: ") . $query->param('userName'));
      print $query->p($query->em("employeeId: ") . $query->param('employeeId'));
      print $query->p($query->em("theDate: ") . $query->param('theDate'));
  
      print $query->hr();
  
      # Set the state for the link to be generated for option one
      $query->param('myState', 'DoPageFourA');
      print $query->a({-href=>$query->url({-query=>1})},
  		    "Choose Link A" );
  
      print $query->br();
  
      # Set the state for the link to be generated for option two
      $query->param('myState', 'DoPageFourB');
      print $query->a({-href=>$query->url({-query=>1})},
  		    "Choose Link B" );
      
      print $query->hr();
  
  }
  
  # See if we are in form 4, branch A of our state thread
  elsif (  $currentState eq 'DoPageFourA' )
  {
      print $query->h1("You chose ", $query->em("Option A"));
      print $query->hr();
      print $query->h2("Here are the values you input so far:");
      print $query->p($query->em("userName: ") . $query->param('userName'));
      print $query->p($query->em("employeeId: ") . $query->param('employeeId'));
      print $query->p($query->em("theDate: ") . $query->param('theDate'));
      print $query->hr();
  }    
  
  # See if we are in form 4, branch B of our state thread
  elsif (  $currentState eq 'DoPageFourB' )
  {
      print $query->h1("You chose ", $query->em("Option B"));
      print $query->hr();
      print $query->h2("Here are the values you input so far:");
      print $query->p($query->em("userName: ") . $query->param('userName'));
      print $query->p($query->em("employeeId: ") . $query->param('employeeId'));
      print $query->p($query->em("theDate: ") . $query->param('theDate'));
      print $query->hr();
  }    
  
  # And finally, end the document.
  
  print $query->end_html;