install4j API

com.install4j.api.beaninfo
Interface PropertyConverter


public interface PropertyConverter

A property converter translates between a string representation and the actual object state and provides an optional property customizer. Property converters are registered on a per-bean basis with Install4JBeanInfo.setPropertyConverters(PropertyConverter[]).

This class and the PropertyConverter class are similar to the PropertyEditor class which was not used in the install4j API since the editing concepts of the install4j IDE do not quite match with the ideas in the java.beans API.

In concept, this class is similar to the EnumerationMapper class.


Field Summary
static java.lang.String DEFAULT_CONTEXT
          A default context that you can use in the getContext() method if there is only one property converter for the property type returned by getPropertyClass()
 
Method Summary
 java.lang.Object fromString(java.lang.String string)
          Converts a string representation to an object of type getPropertyClass().
 java.lang.String getContext()
          The property descriptor of a property that wants to use this property converter must have a non-null context that corresponds to the return value of this method.
 java.lang.Class getPropertyClass()
          Returns the property type for which this property converter is eligible.
 java.lang.Class getPropertyCustomizerClass()
          Returns the class of the optional property customizer.
 boolean supportsFromString()
          Returns if the property converter is able to convert a string representation to an object.
 java.lang.String toString(java.lang.Object object)
          Converts the property value to a string value.
 

Field Detail

DEFAULT_CONTEXT

static final java.lang.String DEFAULT_CONTEXT
A default context that you can use in the getContext() method if there is only one property converter for the property type returned by getPropertyClass()

See Also:
Constant Field Values
Method Detail

getPropertyClass

java.lang.Class getPropertyClass()
Returns the property type for which this property converter is eligible. Derived classes are also captured.

Returns:
the property type

getContext

java.lang.String getContext()
The property descriptor of a property that wants to use this property converter must have a non-null context that corresponds to the return value of this method. In this way the runtime knows that this property converter should be used for displaying and editing a property. The context must not be globally unique, property converters of other property types can use the same context value.

For classes that do not have default handlers in install4j, the property converter will also be used if this method returns DEFAULT_CONTEXT, the getPropertyClass() method returns the class of the property and the context of the property is not set. However, it is safer not to rely on that behavior.

Returns:
the context that will be used by the properties

toString

java.lang.String toString(java.lang.Object object)
Converts the property value to a string value. The string value will be displayed in the install4j IDE. If supportsFromString() returns true, the string value must be valid input for fromString(String) and return an object with the same internal state.

Parameters:
object - the property value of the type returned by getPropertyClass() or possibly of a derived class
Returns:
the string value

supportsFromString

boolean supportsFromString()
Returns if the property converter is able to convert a string representation to an object. If yes, the user will be able to edit the string returned by toString(Object) in the install4j IDE.

Returns:
true if a string can be converted to an object

fromString

java.lang.Object fromString(java.lang.String string)
Converts a string representation to an object of type getPropertyClass(). When editing of the property is completed in the install4j IDE, this method will be called to construct an object that will be set as the property value. This method is only called if supportsFromString() returns true.

Parameters:
string - the string representation
Returns:
the object

getPropertyCustomizerClass

java.lang.Class getPropertyCustomizerClass()
Returns the class of the optional property customizer. If you want to offer a dialog where the user can edit the property value, you have to implement PropertyCustomizer and return the name of your property customizer class, otherwise return null.

If a non-null value is returned, the user will see a "..." button in the install4j IDE that brings up the dialog with the property customizer.

Returns:
the property customizer class or null

install4j API