SetaPDF_Core_Type_Null Class representing a null object
File: /SetaPDF v2/Core/Type/Null.php
Class hierarchy
Implements
Summary
Static Properties
$_instance
Properties
$_observers
The Objects to notify on any change
This will be the PDF document or another value holding this one. Initially this will be an array.
Static Methods
_ensureType()
Ensure that a value is an instance of a specific PDF type.
Parameters
- $type : string
- $value : mixed
- $errorMessage : string
- $ensure
Exceptions
Throws SetaPDF_Core_Type_Exception
ensureType()
Ensures that the passed value is a SetaPDF_Core_Type_AbstractType instance.
Parameters
- $value : mixed
Exceptions
Throws SetaPDF_Core_Type_Exception
ensureWithType()
Ensures that the passed value is an instance of the passed type.
Parameters
- $type : string
- $value : mixed
Exceptions
Throws SetaPDF_Core_Type_Exception
is()
Checks if the type of a value is the expected one.
Indirect references will be evaluated if $ensure
is set to true
.
Parameters
- $type : string
- $value : mixed
- $ensure : bool
writePdfString()
Parses a php null value to a pdf null string and writes it into a writer.
Parameters
- $writer : SetaPDF_Core_WriteInterface
- $value : null
Exceptions
Throws InvalidArgumentException
See
Methods
__sleep()
Implementation of __sleep.
We remove the observers from all elements because they will get read if they are waked up in an observed object.
attach()
Add an observer to the object (will never be called by a NULL object).
Implementation of the Observer Pattern.
Parameters
- $observer : SplObserver
cleanUp()
This method is used to clean up an object by releasing memory and references.
The observers have to be removed with the "detach()"-method. Only if there is no observer left this method should really release resources.
The method has to be implemented by each object type
deepClone()
Clone the object recursively in the context of a document.
Parameters
- $document : SetaPDF_Core_Document
detach()
Detach an observer from the object.
Implementation of the Observer Pattern.
Parameters
- $observer : SplObserver
ensure()
Returns the main value.
This method is used for automatically resolving of indirect references.
Parameters
- $forceObservation : bool|null
notify()
Notifies all attached observers.
Implementation of the Observer Pattern.
Has to be called by any method that changes a value.
setValue()
Implementation of the abstract setValue() method which is useless for this object type.
Parameters
- $value : null
Exceptions
Throws SetaPDF_Core_Type_Exception
See
toPdfString()
Returns the type as a formatted PDF string.
Parameters
- $pdfDocument : SetaPDF_Core_Document|null
writeTo()
Writes the type as a formatted PDF string to the document.
Parameters
- $pdfDocument : SetaPDF_Core_Document