com.yworks.yfiles.graphml

Class MarkupExtension

java.lang.Object

com.yworks.yfiles.graphml.MarkupExtension

public abstract class MarkupExtension
extends Object

Base class for objects that are serialized in GraphML as complex XML elements instead of simple attributes.

Generally, the serialization process first tries to serialize an object to a string attribute using a ValueSerializer. If the ValueSerializer cannot handle the object or the serialization process enforces the output to be a complete XML element, the object is written as an XML element instead. This is done either using a MarkupExtension if present or by the default serialization mechanism.

In general, the serialization process can convert objects to XML elements on its own without having to provide a markup extension if certain requirements are met:

• The class has a default constructor with no arguments.
• The properties of the class have both a getter and setter method.

If the class has no setter method for a property, the property of that class is not written and thus cannot be deserialized.

If the class has no default constructor, the object cannot be serialized at all.

In the case where the default serialization process cannot handle an object properly, a MarkupExtension of the class of the object is required. The MarkupExtension is supposed to adapt the class of the object to a serializable form, i.e. a default constructor and getter and setter methods for the properties that are supposed to be serialized. In addition to this, subclasses of MarkupExtension have to implement the method provideValue(ILookup) which is needed for the deserialization of such an XML element and constructs the object from the given properties.

Note that getter and setter methods for properties of implementations of this class are not supposed to be called by client code. They usually mirror the properties that are contained in the objects they are supposed to provide means to be (de)serialized for. But the filling of these properties are not meant to be done via calling the respective setters, but are either filled by the extension itself or by the serialization process via reflection.

See Also:

MarkupExtension

Constructor Summary

Constructors

Constructor and Description
MarkupExtension()

Method Summary

Modifier and Type	Method and Description
abstract Object	provideValue(ILookup serviceProvider) Returns an object that is set as the value of the target property for this markup extension.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MarkupExtension

public MarkupExtension()

Method Detail

provideValue

public abstract Object provideValue(ILookup serviceProvider)

Returns an object that is set as the value of the target property for this markup extension.

Parameters:

serviceProvider - Object that can provide services for the markup extension.

Returns:

The object value to set on the property where the extension is applied.