Mastering PHP 7

The lazy initialization pattern

The lazy initialization pattern is useful for addressing objects whose instantiation is likely to be resource-intense. The idea is to delay the actual resource intense operation until its result is actually required. The PDF generation is an example of a light to moderately resource-intense operation.

The following example demonstrates a possible lazy initialization pattern implementation based on PDF generation:

<?phpinterface PdfInterface{    public function generate();}class Pdf implements PdfInterface{    private $data;    public function __construct($data)    {        $this->data = $data;        // Imagine resource intensive pdf generation here        sleep(3);    }    public function generate()    {        echo 'pdf: ' . $this->data;    }}class ProxyPdf ...