Question

I have two code examples below. One works, but the second (using extend to create a new class wrapper) doesn’t.

Note, I’ve greatly simplified the following examples.

Approach #1

page.php:

<?php

include("fpdf.php");
$pdf = new FPDF;
$pdf->AddPage();
$pdf->SetFont('Arial','',11);
$pdf->Output();

?>

This works as expected. It creates a blank page.

Approach #2

But then, using the FPDF by inheritance, I get an error (see below the code blocks).

myPDF.php:

<?php

require ("fpdf.php");

class myPDF extends FPDF {

    function createMyPage() {
        $this->AddPage();
        $this->SetFont('Arial','',11);
        $this->Output();
    }

}

?>

page.php:

<?php

include("myPDF.php");
$pdf = new myPDF;
$pdf->createMyPage();

?>

This second approach produces the following PHP warning and FPDF error:

Warning: in_array() expects parameter 2 to be array, null given in /var/www/fpdftest/fpdf.php on line 526 FPDF error: Undefined font: helvetica

Any ideas what I’m missing here?

Answer 1

When you create your wrapper class, be sure to call the parent constructor:

<?php // Always use the full <?php open tag

require ("fpdf.php");

class myPDF extends FPDF {

    // Or, __construct() if you only care about PHP5
    function myPDF($orientation='P', $unit='mm', $size='A4') {
        // Call parent constructor
        $this->FPDF($orientation,$unit,$size);
        // Initialization
        $this->B = 0;
        $this->I = 0;
        $this->U = 0;
        $this->HREF = '';
    }

    function createMyPage() {
        $this->AddPage();
        $this->SetFont('Arial','',11);
        $this->Output();
    }

}

http://fpdf.org/en/tutorial/tuto6.htm