org.apache.tools.ant.types

Class DataType

Implemented Interfaces:
Cloneable
Known Direct Subclasses:
AbstractFileSet, AbstractSelectorContainer, AntFilterReader, Assertions, BaseResourceCollectionContainer, BaseResourceCollectionWrapper, BaseSelector, Compare, Description, ExtensionAdapter, ExtensionSet, FileList, FilterChain, FilterSet, ImageOperation, IsSigned, Mapper, Path, PatternSet, PropertySet, RedirectorElement, RegularExpression, Resource, ResourceComparator, Resources, ResourceSelectorContainer, SignedSelector, Substitution, XMLCatalog

public abstract class DataType
extends ProjectComponent
implements Cloneable

Base class for those classes that can appear inside the build file as stand alone data types.

This class handles the common description attribute and provides a default implementation for reference handling and checking for circular references that is appropriate for types that can not be nested inside elements of the same type (i.e. <patternset> but not <path>).

Field Summary

protected boolean
checked
Deprecated. since 1.7.
protected Reference
ref
Deprecated. since 1.7.

Fields inherited from class org.apache.tools.ant.ProjectComponent

description, location, project

Method Summary

protected void
checkAttributesAllowed()
check that it is ok to set attributes, i.e that no reference is defined
protected void
checkChildrenAllowed()
check that it is ok to add children, i.e that no reference is defined
protected BuildException
circularReference()
Creates an exception that indicates the user has generated a loop of data types referencing each other.
Object
clone()
protected void
dieOnCircularReference()
Convenience method.
protected void
dieOnCircularReference(Stack stack, Project project)
Check to see whether any DataType we hold references to is included in the Stack (which holds all DataType instances that directly or indirectly reference this instance, including this instance itself).
protected void
dieOnCircularReference(Project p)
Convenience method.
protected Object
getCheckedRef()
Performs the check for circular references and returns the referenced object.
protected Object
getCheckedRef(Class requiredClass, String dataTypeName)
Performs the check for circular references and returns the referenced object.
protected Object
getCheckedRef(Class requiredClass, String dataTypeName, Project project)
Performs the check for circular references and returns the referenced object.
protected Object
getCheckedRef(Project p)
Performs the check for circular references and returns the referenced object.
protected String
getDataTypeName()
Gets as descriptive as possible a name used for this datatype instance.
Reference
getRefid()
get the reference set on this object
static void
invokeCircularReferenceCheck(DataType dt, Stack stk, Project p)
Allow DataTypes outside org.apache.tools.ant.types to indirectly call dieOnCircularReference on nested DataTypes.
protected boolean
isChecked()
The flag that is used to indicate that circular references have been checked.
boolean
isReference()
Has the refid attribute of this element been set?
protected BuildException
noChildrenAllowed()
Creates an exception that indicates that this XML element must not have child elements if the refid attribute is set.
protected void
setChecked(boolean checked)
Set the flag that is used to indicate that circular references have been checked.
void
setRefid(Reference ref)
Set the value of the refid attribute.
String
toString()
Basic DataType toString().
protected BuildException
tooManyAttributes()
Creates an exception that indicates that refid has to be the only attribute if it is set.

Methods inherited from class org.apache.tools.ant.ProjectComponent

clone, getDescription, getLocation, getProject, log, log, setDescription, setLocation, setProject

Field Details

checked

protected boolean checked

Deprecated. since 1.7. The user should not be directly referencing variable. Please use setChecked(boolean) or isChecked() instead.

Are we sure we don't hold circular references?

Subclasses are responsible for setting this value to false if we'd need to investigate this condition (usually because a child element has been added that is a subclass of DataType).


ref

protected Reference ref

Deprecated. since 1.7. The user should not be directly referencing variable. Please use getRefid() instead.

Value to the refid attribute.

Method Details

checkAttributesAllowed

protected void checkAttributesAllowed()
check that it is ok to set attributes, i.e that no reference is defined
Since:
Ant 1.6

checkChildrenAllowed

protected void checkChildrenAllowed()
check that it is ok to add children, i.e that no reference is defined
Since:
Ant 1.6

circularReference

protected BuildException circularReference()
Creates an exception that indicates the user has generated a loop of data types referencing each other.
Returns:
the exception to throw

clone

public Object clone()
            throws CloneNotSupportedException
Overrides:
clone in interface ProjectComponent
Returns:
a shallow copy of this DataType.
Since:
Ant 1.7

dieOnCircularReference

protected void dieOnCircularReference()
Convenience method.
Since:
Ant 1.7

dieOnCircularReference

protected void dieOnCircularReference(Stack stack,
                                      Project project)
            throws BuildException
Check to see whether any DataType we hold references to is included in the Stack (which holds all DataType instances that directly or indirectly reference this instance, including this instance itself).

If one is included, throw a BuildException created by circularReference.

This implementation is appropriate only for a DataType that cannot hold other DataTypes as children.

The general contract of this method is that it shouldn't do anything if checked is true and set it to true on exit.

Parameters:
stack - the stack of references to check.
project - the project to use to dereference the references.
Throws:
BuildException - on error.

dieOnCircularReference

protected void dieOnCircularReference(Project p)
Convenience method.
Parameters:
p - the Ant Project instance against which to resolve references.
Since:
Ant 1.7

getCheckedRef

protected Object getCheckedRef()
Performs the check for circular references and returns the referenced object.
Returns:
the dereferenced object.
Since:
Ant 1.7

getCheckedRef

protected Object getCheckedRef(Class requiredClass,
                               String dataTypeName)
Performs the check for circular references and returns the referenced object.
Parameters:
requiredClass - the class that this reference should be a subclass of.
dataTypeName - the name of the datatype that the reference should be (error message use only).
Returns:
the dereferenced object.

getCheckedRef

protected Object getCheckedRef(Class requiredClass,
                               String dataTypeName,
                               Project project)
Performs the check for circular references and returns the referenced object. This version allows the fallback Project instance to be specified.
Parameters:
requiredClass - the class that this reference should be a subclass of.
dataTypeName - the name of the datatype that the reference should be (error message use only).
project - the fallback Project instance for dereferencing.
Returns:
the dereferenced object.
Since:
Ant 1.7

getCheckedRef

protected Object getCheckedRef(Project p)
Performs the check for circular references and returns the referenced object.
Parameters:
p - the Ant Project instance against which to resolve references.
Returns:
the dereferenced object.
Since:
Ant 1.7

getDataTypeName

protected String getDataTypeName()
Gets as descriptive as possible a name used for this datatype instance.
Returns:
String name.

getRefid

public Reference getRefid()
get the reference set on this object
Returns:
the reference or null

invokeCircularReferenceCheck

public static void invokeCircularReferenceCheck(DataType dt,
                                                Stack stk,
                                                Project p)
Allow DataTypes outside org.apache.tools.ant.types to indirectly call dieOnCircularReference on nested DataTypes.
Parameters:
dt - the DataType to check.
stk - the stack of references to check.
p - the project to use to dereference the references.
Since:
Ant 1.7

isChecked

protected boolean isChecked()
The flag that is used to indicate that circular references have been checked.
Returns:
true if circular references have been checked

isReference

public boolean isReference()
Has the refid attribute of this element been set?
Returns:
true if the refid attribute has been set

noChildrenAllowed

protected BuildException noChildrenAllowed()
Creates an exception that indicates that this XML element must not have child elements if the refid attribute is set.
Returns:
the exception to throw

setChecked

protected void setChecked(boolean checked)
Set the flag that is used to indicate that circular references have been checked.
Parameters:
checked - if true, if circular references have been checked

setRefid

public void setRefid(Reference ref)
Set the value of the refid attribute.

Subclasses may need to check whether any other attributes have been set as well or child elements have been created and thus override this method. if they do the must call super.setRefid.

Parameters:
ref - the reference to use

toString

public String toString()
Basic DataType toString().
Returns:
this DataType formatted as a String.

tooManyAttributes

protected BuildException tooManyAttributes()
Creates an exception that indicates that refid has to be the only attribute if it is set.
Returns:
the exception to throw