pdftk-php.php

<?php

##################################################################################################################
#
#	pdftk-php Class
#	http://code.google.com/p/pdftk-php/
#	http://www.pdfhacks.com/forge_fdf/
#
#	License: Released under New BSD license - http://www.opensource.org/licenses/bsd-license.php
#
#	Purpose: Contains functions used to inject data from MySQL into an empty PDF form
#
#	Authors: Andrew Heiss (www.andrewheiss.com), Sid Steward (http://www.oreillynet.com/pub/au/1754)
#
#	History: 
#		8/26/08 - Initial programming
#
#	Usage: 
#		$pdfmaker = new pdftk_php;
#
#		$fdf_data_strings = array();
#		$fdf_data_names = array(); 
#		$fields_hidden = array(); 
#		$fields_readonly = array();
#		$pdf_original = "string"; = filename of the original, empty pdf form
#		$pdf_filename = "string"; = filename to be used for the output pdf
#
#		$pdfmaker->make_pdf($fdf_data_strings, $fdf_data_names, $fields_hidden, $fields_readonly, $pdf_filename);
#
##################################################################################################################

	class pdftk_php { 		

#############################################################################
#
#	Function name: makePDF
#
#	Purpose: Generate an FDF file from db data, inject the FDF in an empty PDF form
#
#	Incoming parameters: 
#		$fetched_array - one row of fetched MySQL data saved as a variable
#
#	Returns: Downloaded PDF file
#
#	Notes:
#		* For text fields, combo boxes and list boxes, add field values as a name => value pair to $fdf_data_strings. An example of $fdf_data_strings is given in /example/download.php
#		* For check boxes and radio buttons, add field values as a name => value pair to $fdf_data_names.  Typically, true and false correspond to the (case sensitive) names "Yes" and "Off".
#		* Any field added to the $fields_hidden or $fields_readonly array must also be a key in $fdf_data_strings or $fdf_data_names; this might be changed in the future
#		* Any field listed in $fdf_data_strings or $fdf_data_names that you want hidden or read-only must have its field name added to $fields_hidden or $fields_readonly; do this even if your form has these bits set already 
#
#############################################################################
	
		public function make_pdf($fdf_data_strings, $fdf_data_names, $fields_hidden, $fields_readonly, $pdf_original, $pdf_filename) {
			// Create the fdf file
			$fdf = $this->forge_fdf('', $fdf_data_strings, $fdf_data_names, $fields_hidden, $fields_readonly);
			
			// Save the fdf file temporarily - make sure the server has write permissions in the folder you specify in tempnam()
			$fdf_fn = tempnam(".", "fdf");
			$fp = fopen($fdf_fn, 'w');
			
			if($fp) {
				fwrite($fp, $fdf);
				fclose($fp);
				
				// Send a force download header to the browser with a file MIME type
				header("Content-Type: application/force-download");
				header("Content-Disposition: attachment; filename=\"$pdf_filename\"");
				
				// Actually make the PDF by running pdftk - make sure the path to pdftk is correct
				// The PDF will be output directly to the browser - apart from the original PDF file, no actual PDF wil be saved on the server.
				passthru("/usr/local/bin/pdftk $pdf_original fill_form $fdf_fn output - flatten");
				
				// delete temporary fdf file
				unlink( $fdf_fn ); 
			}
			else { // error
				echo 'Error: unable to write temp fdf file: '. $fdf_fn;
			}
			
		} // end of make_pdf()
		
		
		protected function forge_fdf($pdf_form_url, &$fdf_data_strings, &$fdf_data_names, &$fields_hidden, &$fields_readonly) {
		
		/* forge_fdf, by Sid Steward
		   version 1.1
		   visit: www.pdfhacks.com/forge_fdf/
		   
		   PDF can be particular about CR and LF characters, so I spelled them out in hex: CR == \x0d : LF == \x0a
		   
		*/
			$fdf = "%FDF-1.2\x0d%\xe2\xe3\xcf\xd3\x0d\x0a"; // header
			$fdf.= "1 0 obj\x0d<< "; // open the Root dictionary
			$fdf.= "\x0d/FDF << "; // open the FDF dictionary
			$fdf.= "/Fields [ "; // open the form Fields array
			
			$fdf_data_strings = $this->burst_dots_into_arrays( $fdf_data_strings );
			$this->forge_fdf_fields_strings( $fdf,
						$fdf_data_strings,
						$fields_hidden,
						$fields_readonly );
			
			$fdf_data_names= $this->burst_dots_into_arrays( $fdf_data_names );
			$this->forge_fdf_fields_names( $fdf,
					  $fdf_data_names,
					  $fields_hidden,
					  $fields_readonly );
			
			$fdf.= "] \x0d"; // close the Fields array
			
			// the PDF form filename or URL, if given
			if( $pdf_form_url ) {
			$fdf.= "/F (".$this->escape_pdf_string($pdf_form_url).") \x0d";
			}
			
			$fdf.= ">> \x0d"; // close the FDF dictionary
			$fdf.= ">> \x0dendobj\x0d"; // close the Root dictionary
			
			// trailer; note the "1 0 R" reference to "1 0 obj" above
			$fdf.= "trailer\x0d<<\x0d/Root 1 0 R \x0d\x0d>>\x0d";
			$fdf.= "%%EOF\x0d\x0a";
			
			return $fdf;
		}
		
		public function escape_pdf_string( $ss ) {
		  $backslash= chr(0x5c);
		  $ss_esc= '';
		  $ss_len= strlen( $ss );
		  for( $ii= 0; $ii< $ss_len; ++$ii ) {
			if( ord($ss{$ii})== 0x28 ||  // open paren
			ord($ss{$ii})== 0x29 ||  // close paren
			ord($ss{$ii})== 0x5c )   // backslash
			  {
			$ss_esc.= $backslash.$ss{$ii}; // escape the character w/ backslash
			  }
			else if( ord($ss{$ii}) < 32 || 126 < ord($ss{$ii}) ) {
			  $ss_esc.= sprintf( "\\%03o", ord($ss{$ii}) ); // use an octal code
			}
			else {
			  $ss_esc.= $ss{$ii};
			}
		  }
		  return $ss_esc;
		}

		protected function escape_pdf_name( $ss ) {
		  $ss_esc= '';
		  $ss_len= strlen( $ss );
		  for( $ii= 0; $ii< $ss_len; ++$ii ) {
			if( ord($ss{$ii}) < 33 || 126 < ord($ss{$ii}) || 
			ord($ss{$ii})== 0x23 ) // hash mark
			  {
			$ss_esc.= sprintf( "#%02x", ord($ss{$ii}) ); // use a hex code
			  }
			else {
			  $ss_esc.= $ss{$ii};
			}
		  }
		  return $ss_esc;
		}

		// In PDF, partial form field names are combined using periods to
		// yield the full form field name; we'll take these dot-delimited
		// names and then expand them into nested arrays, here; takes
		// an array that uses dot-delimited names and returns a tree of arrays;
		//
		protected function burst_dots_into_arrays( &$fdf_data_old ) {
		  $fdf_data_new= array();
		
		  foreach( $fdf_data_old as $key => $value ) {
			$key_split= explode( '.', (string)$key, 2 );
		
			if( count($key_split)== 2 ) { // handle dot
			  if( !array_key_exists( (string)($key_split[0]), $fdf_data_new ) ) {
			$fdf_data_new[ (string)($key_split[0]) ]= array();
			  }
			  if( gettype( $fdf_data_new[ (string)($key_split[0]) ] )!= 'array' ) {
			// this new key collides with an existing name; this shouldn't happen;
			// associate string value with the special empty key in array, anyhow;
		
			$fdf_data_new[ (string)($key_split[0]) ]= 
			  array( '' => $fdf_data_new[ (string)($key_split[0]) ] );
			  }
		
			  $fdf_data_new[ (string)($key_split[0]) ][ (string)($key_split[1]) ]= $value;
			}
			else { // no dot
			  if( array_key_exists( (string)($key_split[0]), $fdf_data_new ) &&
			  gettype( $fdf_data_new[ (string)($key_split[0]) ] )== 'array' )
			{ // this key collides with an existing array; this shouldn't happen;
			  // associate string value with the special empty key in array, anyhow;
		
			  $fdf_data_new[ (string)$key ]['']= $value;
			}
			  else { // simply copy
			$fdf_data_new[ (string)$key ]= $value;
			  }
			}
		  }
		
		  foreach( $fdf_data_new as $key => $value ) {
			if( gettype($value)== 'array' ) {
			  $fdf_data_new[ (string)$key ]= $this->burst_dots_into_arrays( $value ); // recurse
			}
		  }
		
		  return $fdf_data_new;
		}

		protected function forge_fdf_fields_flags( &$fdf,
					$field_name,
					&$fields_hidden,
					&$fields_readonly ) {
		  if( in_array( $field_name, $fields_hidden ) )
			$fdf.= "/SetF 2 "; // set
		  else
			$fdf.= "/ClrF 2 "; // clear
		
		  if( in_array( $field_name, $fields_readonly ) )
			$fdf.= "/SetFf 1 "; // set
		  else
			$fdf.= "/ClrFf 1 "; // clear
		}

		protected function forge_fdf_fields( &$fdf,
				  &$fdf_data,
				  &$fields_hidden,
				  &$fields_readonly,
				  $accumulated_name,
				  $strings_b ) // true <==> $fdf_data contains string data
			 //
			 // string data is used for text fields, combo boxes and list boxes;
			 // name data is used for checkboxes and radio buttons, and
			 // /Yes and /Off are commonly used for true and false
		{
		  if( 0< strlen( $accumulated_name ) ) {
			$accumulated_name.= '.'; // append period seperator
		  }
		
		  foreach( $fdf_data as $key => $value ) {
			// we use string casts to prevent numeric strings from being silently converted to numbers
		
			$fdf.= "<< "; // open dictionary
		
			if( gettype($value)== 'array' ) { // parent; recurse
			  $fdf.= "/T (".$this->escape_pdf_string( (string)$key ).") "; // partial field name
			  $fdf.= "/Kids [ ";                                    // open Kids array
		
			  // recurse
			  $this->forge_fdf_fields( $fdf,
					$value,
					$fields_hidden,
					$fields_readonly,
					$accumulated_name. (string)$key,
					$strings_b );
		
			  $fdf.= "] "; // close Kids array
			}
			else {
		
			  // field name
			  $fdf.= "/T (".$this->escape_pdf_string( (string)$key ).") ";
		
			  // field value
			  if( $strings_b ) { // string
			$fdf.= "/V (".$this->escape_pdf_string( (string)$value ).") ";
			  }
			  else { // name
			$fdf.= "/V /".$this->escape_pdf_name( (string)$value ). " ";
			  }
		
			  // field flags
			  $this->forge_fdf_fields_flags( $fdf,
						  $accumulated_name. (string)$key,
						  $fields_hidden,
						  $fields_readonly );
			}
		
			$fdf.= ">> \x0d"; // close dictionary
		  }
		  
		}


		protected function forge_fdf_fields_strings( &$fdf,
					  &$fdf_data_strings,
					  &$fields_hidden,
					  &$fields_readonly ) {
		  return
			$this->forge_fdf_fields( $fdf,
					  $fdf_data_strings,
					  $fields_hidden,
					  $fields_readonly,
					  '',
					  true ); // true => strings data
		}


		protected function forge_fdf_fields_names( &$fdf,
					&$fdf_data_names,
					&$fields_hidden,
					&$fields_readonly ) {
		  return
			$this->forge_fdf_fields( $fdf,
					  $fdf_data_names,
					  $fields_hidden,
					  $fields_readonly,
					  '',
					  false ); // false => names data
		}
	
	
	}
?>