Chapter 10. PDF

10.2 Documents and Pages

A PHP document is made up of a number of pages. Each page contains text and/or images. This section shows you how to make a document, create pages in that document, put text onto the pages, and send the pages back to the browser when you're done.

10.2.1 A Simple Example

Let's start with a simple PDF document. Example 10-1 simply places "Hello world!" on a page and then displays the resulting PDF document.

Example 10-1. Hello world in PDF

<?php 
 $pdf = pdf_new(  ); 
 pdf_open_file($pdf);
 pdf_set_info($pdf,'Creator','hello.php'); 
 pdf_set_info($pdf,'Author','Rasmus Lerdorf'); 
 pdf_set_info($pdf,'Title','Hello world (PHP)'); 
 pdf_begin_page($pdf,612,792); 

 $font = pdf_findfont($pdf,'Helvetica-Bold','host',0);        
 pdf_setfont($pdf,$font,38.0); 
 pdf_show_xy($pdf,'Hello world!',50,700);

 pdf_end_page($pdf); 
 pdf_set_parameter($pdf, "openaction", "fitpage");
 pdf_close($pdf); 

 $buf = pdf_get_buffer($pdf); 
 $len = strlen($buf);
 header('Content-Type: application/pdf');
 header("Content-Length: $len");
 header('Content-Disposition: inline; filename=hello.pdf');
 echo $buf;
 pdf_delete($pdf);
?>

Example 10-1 follows the basic steps involved in creating a PDF document: creating a new document, setting some metadata for the document, creating a page, and writing text to the page. Figure 10-1 shows the output of Example 10-1.

Figure 10-1. Hello world in a PDF document

10.2.2 Initializing the Document

In Example 10-1, we started by calling pdf_new( ) , to create a new PDF data structure, followed by pdf_open_file( ) , to open a new document. pdf_open_file( ) takes an optional second argument that, when set, specifies the filename to which to write the PDF data:

pdf_open_file(


pdf


[,


filename


]);

The output of pdf_open_file( ) is sent to stdout if the filename is "-" . If no filename argument is provided, the PDF data is written to a memory buffer, which can later be fetched by calling pdf_get_buffer( ) . The latter approach is the one we used in Example 10-1.

10.2.3 Setting Metadata

The pdf_set_info( ) function inserts information fields into the PDF file:

pdf_set_info(


pdf


,


fieldname


,


value


);

There are five standard field names : Subject , Author , Title , Creator , and Keywords . You can also add arbitrary information fields, as we did in Example 10-1.

In addition to informational fields, the pdflib library has various parameters that you can change with pdf_get_parameter( ) and pdf_set_parameter( ) :

$value = pdf_get_parameter(


pdf


,


name


);
pdf_set_parameter(


pdf


,


name


,


value


);

A useful parameter to set is openaction , which lets you specify the zoom (magnification) of the file when it's opened. The values "fitpage" , "fitwidth" , and "fitheight" fit the file to the complete page, the width of the page, and the height of the page, respectively. If you don't set openaction , your document is displayed at whatever zoom the viewer had set at the time the document was opened.

10.2.4 Creating a Page

A page starts with a call to pdf_begin_page( ) and ends with a call to pdf_end_page( ) :

pdf_end_page(


pdf


);

You specify the paper size in points in the call to pdf_begin_page( ) . Table 10-1 shows some typical sizes.

Table 10-1. Paper sizes

<?php
 pdf_begin_page($pdf, 612, 792);  // US-Letter
 // code to create actual page content would go here 
 pdf_end_page($pdf);
?>

$font = pdf_findfont($pdf, "Times-Roman", "host", 0);
pdf_setfont($pdf, $font, 48);
pdf_show_xy($pdf, "Hello, World", 200, 200);