The Zend_Pdf
class represents PDF documents and provides document-level
operations.
To create a new document, a new Zend_Pdf
object should first be created.
Zend_Pdf
class also provides two static methods to load an existing PDF document.
These are the Zend_Pdf::load()
and Zend_Pdf::parse()
methods.
Both of them return Zend_Pdf
objects as a result or throw an exception if an error occurs.
Example 40.1. Create new or load existing PDF document
... // Create a new PDF document $pdf1 = new Zend_Pdf(); // Load a PDF document from a file $pdf2 = Zend_Pdf::load($fileName); // Load a PDF document from a string $pdf3 = Zend_Pdf::parse($pdfString); ...
The PDF file format supports incremental document update. Thus each time a document
is updated, then a new revision of the document is created.
Zend_Pdf
component supports the retrieval of a specified revision.
A revision can be specified as a second parameter to the Zend_Pdf::load()
and
Zend_Pdf::parse()
methods or requested by calling the Zend_Pdf::rollback()
method.
[4]
call.
Example 40.2. Requesting Specific Revisions of a PDF Document
... // Load the previous revision of the PDF document $pdf1 = Zend_Pdf::load($fileName, 1); // Load the previous revision of the PDF document $pdf2 = Zend_Pdf::parse($pdfString, 1); // Load the first revision of the PDF document $pdf3 = Zend_Pdf::load($fileName); $revisions = $pdf3->revisions(); $pdf3->rollback($revisions - 1); ...
[4]
Zend_Pdf::rollback()
method must be invoked before any changes are applied to the document,
otherwise the behavior is not defined.