org.apache.tapestry5.plastic
Interface PlasticField

All Superinterfaces:

AnnotationAccess

public interface PlasticField
extends AnnotationAccess

Represents a field of a class being transformed.

No methods of this object should be invoked after the class transformation is completed.

Method Summary

PlasticField	claim(Object tag) Claims the field, used to indicate that the field is "processed".
PlasticField	createAccessors(PropertyAccessType accessType) Creates access to the field, using the default property name derived from the name of the field.
PlasticField	createAccessors(PropertyAccessType accessType, String propertyName) Creates accessors, possibly replacing existing methods (or overriding methods from a super class).
String	getGenericSignature() Returns the field's fully qualified generic type, or null if not defined.
FieldHandle	getHandle() Returns a handle that can be used to directly access a private field of a transformed class instance.
int	getModifiers() Returns the modifiers on the field.
String	getName() Returns the name of the field.
PlasticClass	getPlasticClass() Returns the class containing this field.
String	getTypeName() Returns the fully qualified class name for the field's type or (for a primitive type) the primitive type name ("int", "char", etc.).
PlasticField	inject(Object value) Converts the field to be read-only, and provide the indicated value.
PlasticField	injectComputed(ComputedValue<?> computedValue) Converts the field to be read-only, and provide the value, which is computed indirectly inside the class' constructor.
PlasticField	injectFromInstanceContext() As with inject(Object), but the value is extracted from the InstanceContext.
boolean	isClaimed() Returns true if the field has already been claimed.
<F> PlasticField	setComputedConduit(ComputedValue<FieldConduit<F>> computedConduit) Sets the conduit for the field to a value computed when the class is instantiated
<F> PlasticField	setConduit(FieldConduit<F> conduit) Intercepts all access to the field, replacing such access with calls on the conduit.

Methods inherited from interface org.apache.tapestry5.plastic.AnnotationAccess

getAnnotation, hasAnnotation

Method Detail

getPlasticClass

PlasticClass getPlasticClass()

Returns the class containing this field.

getHandle

FieldHandle getHandle()

Returns a handle that can be used to directly access a private field of a transformed class instance.

getName

String getName()

Returns the name of the field.

getTypeName

String getTypeName()

Returns the fully qualified class name for the field's type or (for a primitive type) the primitive type name ("int", "char", etc.). For array types, the returned name includes a "[]" suffix.

claim

PlasticField claim(Object tag)

Claims the field, used to indicate that the field is "processed". A field may only be claimed once. Claiming a field is intended as a mechanism to detect or prevent conflicts between different isolated transformations of the field. The tag value used does not matter, and is typically either an annotation (that drove the transformation) or the instance of PlasticClassTransformer that performed the transformation. That tag value is only used when generating the error message for the case where a field is claimed for than once.

Returns:

the field for further manipulation

Throws:

RuntimeException - if the field is claimed a second time

AssertionError - if tag is null

See Also:

PlasticClass.getUnclaimedFields()

isClaimed

boolean isClaimed()

Returns true if the field has already been claimed.

See Also:

PlasticClass.getUnclaimedFields()

inject

PlasticField inject(Object value)

Converts the field to be read-only, and provide the indicated value. The field's value will be set inside the class' constructor.

Parameters:

value - to inject, which must be type compatible with the field (possibly, a wrapper type if the field is a primitive value). The value may not be null.

Returns:

the field for further manipulation

Throws:

IllegalStateException - if the field already has an injection, or the field has a conduit

injectComputed

PlasticField injectComputed(ComputedValue<?> computedValue)

Converts the field to be read-only, and provide the value, which is computed indirectly inside the class' constructor.

Parameters:

computedValue - provides the actual value to be injected, and must return a value type compatible with the field (possibly a wrapper type if the field is a primitive value). The computedValue may not be null.

Returns:

the field for further manipulation

Throws:

IllegalStateException - if the field already has an injection, or the field has a conduit

injectFromInstanceContext

PlasticField injectFromInstanceContext()

As with inject(Object), but the value is extracted from the InstanceContext.

Returns:

this field for further manipulation

setConduit

<F> PlasticField setConduit(FieldConduit<F> conduit)

Intercepts all access to the field, replacing such access with calls on the conduit. Even access via the FieldHandle will instead delegate to the conduit. Once a conduit is provided, it is not possible to inject a value into the field.

Normally, once a conduit is in place, the field will never be actually read or written. This is problematic for debugging, so TransformationOption.FIELD_WRITEBEHIND is useful when operating in a non-production mode.

Returns:

the field for further manipulation

Throws:

IllegalStateException - if the field already has an injection or a conduit

setComputedConduit

<F> PlasticField setComputedConduit(ComputedValue<FieldConduit<F>> computedConduit)

Sets the conduit for the field to a value computed when the class is instantiated

Parameters:

computedConduit - object that will compute the actual conduit to be used

Returns:

this field for further manipulation

createAccessors

PlasticField createAccessors(PropertyAccessType accessType)

Creates access to the field, using the default property name derived from the name of the field. The default property name is the same as the name of the field, but with any leading or trailing underscore characters removed (a common convention among some programmers). Also, strips leading "m_" from the field name (another common convention).

Parameters:

accessType - which methods to create

Returns:

the field for further manipulation

Throws:

IllegalArgumentException - if an accessor method to be created already exists (possibly inherited from a base class)

createAccessors

PlasticField createAccessors(PropertyAccessType accessType,
                             String propertyName)

Creates accessors, possibly replacing existing methods (or overriding methods from a super class). The method names consist of the property name, with its first character converted to upper-case, prefixed with "get" or "set". The accessor methods must not already exist.

Parameters:

accessType - which methods to create

propertyName - the name of the property (from which the names of the methods are generated)

Returns:

the field for further manipulation

Throws:

IllegalArgumentException - if an accessor method to be created already exists (possibly inherited from a base class)

getGenericSignature

String getGenericSignature()

Returns the field's fully qualified generic type, or null if not defined.

getModifiers

int getModifiers()

Returns the modifiers on the field.