org.smartfrog.sfcore.reference
Class Reference

java.lang.Object
  org.smartfrog.sfcore.reference.Reference

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Copying

Direct Known Subclasses:

ApplyReference, SFReference

public class Reference
extends java.lang.Object
implements Copying, java.lang.Cloneable, java.io.Serializable

A reference is a list of ReferencePart objects. An example of a reference is: ATTRIB a-b, which would resolve to an attribute in one of the containing contexts called a, which has to be a component that contains an attribute named b. <br > WARNING: References are not safe for use in hashtables (and therefor as attribute keys) if they are modified, since the hashCode is based on the first element.

See Also:

Serialized Form

Field Summary

protected boolean	data Indicator whether reference is data or link.
protected boolean	eager Indicator whether reference is eager or lazy.
static int	inc Capacity increment for references.
static int	initCap Initial capacity for references.
protected java.util.Vector	ref Actual reference.

Constructor Summary

Reference()
Constructs an empty reference.

Reference(java.lang.Object referencePart)
Constructs a reference with a single reference part from a String.

Reference(ReferencePart referencePart)
Constructs a reference with a single reference part.

Reference(java.lang.String refString, boolean parse)
Constructs a reference with a single reference part from a String or from a string in cannonical form using the parser.

Method Summary

ReferencePart	addElement(ReferencePart o) Adds element to the end of the reference.
Reference	addElements(Reference ref) Adds a reference to the end of the reference.
java.lang.Object	clone() Makes a clone of the reference.
Reference	clone(int start, int len) Clone this reference from start with length elements.
java.lang.Object	copy() Returns a copy of the reference, by cloning itself and then copying all the reference parts.
ReferencePart	elementAt(int index) Returns element at index.
java.util.Enumeration	elements() Returns an enumeration over the elements of the reference.
boolean	equals(java.lang.Object ref) Checks if this and given reference are equal.
ReferencePart	firstElement() Returns first element of reference.
static Reference	fromString(java.lang.String refString) Utility method to create a reference from a string.
boolean	getData() Gets the data flag for the reference.
boolean	getEager() Gets the eager flag for the reference.
int	hashCode() Returns the hashcode for this reference.
ReferencePart	lastElement() Returns last element in reference.
boolean	removeElement(ReferencePart o) Remove element from reference.
java.lang.Object	resolve(ReferenceResolver rr, int index) Resolves this reference using the given reference resolver, and starting at index of this reference.
java.lang.Object	resolve(RemoteReferenceResolver rr, int index) Resolves this reference using the given remote reference resolver, and starting at index of this reference.
boolean	setData(boolean data) Sets the data flag for the reference.
boolean	setEager(boolean eager) Sets the eager flag for the reference.
ReferencePart	setElementAt(ReferencePart elem, int index) Sets the element at given index to a new element.
int	size() Returns the size of the reference.
java.lang.String	toString() Returns string representation of the reference.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

initCap

public static int initCap

Initial capacity for references. Looks up Reference.initCap (offset by propBase). Defaults to 5 if not there

See Also:

Reference

inc

public static int inc

Capacity increment for references. Looks up Reference.inc (offset by propBase). Defaults to 2 if not there

See Also:

Reference

ref

protected java.util.Vector ref

Actual reference.

eager

protected boolean eager

Indicator whether reference is eager or lazy.

data

protected boolean data

Indicator whether reference is data or link.

Constructor Detail

Reference

public Reference()

Constructs an empty reference.

Reference

public Reference(java.lang.Object referencePart)

Constructs a reference with a single reference part from a String.

Parameters:

referencePart - part to be put in reference

Reference

public Reference(java.lang.String refString,
                 boolean parse)
          throws SmartFrogResolutionException

Constructs a reference with a single reference part from a String or from a string in cannonical form using the parser.

Parameters:

refString - to be put/used in reference

parse - boolean to ask for string reference to be parsed or not

Throws:

SmartFrogResolutionException - if reference is not valid

Reference

public Reference(ReferencePart referencePart)

Constructs a reference with a single reference part.

Parameters:

referencePart - part to be put in reference

Method Detail

fromString

public static Reference fromString(java.lang.String refString)
                            throws SmartFrogResolutionException

Utility method to create a reference from a string. Uses the SFParser class.

Parameters:

refString - string representing reference

Returns:

new reference parsed from string

Throws:

SmartFrogResolutionException - if illegal reference in string

copy

public java.lang.Object copy()

Returns a copy of the reference, by cloning itself and then copying all the reference parts.

Specified by:

copy in interface Copying

Returns:

copy of reference

See Also:

Copying

clone

public java.lang.Object clone()

Makes a clone of the reference. The inside ref holder is cloned, but the contained reference parts are NOT. If a CloneException occurs null is returned

Specified by:

clone in interface Copying

Overrides:

clone in class java.lang.Object

Returns:

clone of reference or null on clone error

clone

public Reference clone(int start,
                       int len)

Clone this reference from start with length elements. Reference parts are NOT copied. On clone failure, null is returned

Parameters:

start - index for copy

len - length of copy

Returns:

clone of part of reference

getEager

public boolean getEager()

Gets the eager flag for the reference.

Returns:

current eager flag

See Also:

setEager(boolean)

setEager

public boolean setEager(boolean eager)

Sets the eager flag for the reference.

Parameters:

eager - new eager flag

Returns:

old eager flag

See Also:

getEager()

getData

public boolean getData()

Gets the data flag for the reference.

Returns:

current data flag

See Also:

setData(boolean)

setData

public boolean setData(boolean data)

Sets the data flag for the reference.

Parameters:

data - new data flag

Returns:

old data flag

See Also:

getData()

equals

public boolean equals(java.lang.Object ref)

Checks if this and given reference are equal. Two references are considered to be equal if all their reference parts are equal. Reference equality does NOT mean that the two references point to the same object

Overrides:

equals in class java.lang.Object

Parameters:

ref - to be compared

Returns:

true if equal, false if not

hashCode

public int hashCode()

Returns the hashcode for this reference. Hash code for reference is made out of the sum of the parts hashcodes

Overrides:

hashCode in class java.lang.Object

Returns:

integer hashcode

elements

public java.util.Enumeration elements()

Returns an enumeration over the elements of the reference.

Returns:

enumeration of elements

size

public int size()

Returns the size of the reference.

Returns:

size of reference

elementAt

public ReferencePart elementAt(int index)

Returns element at index.

Parameters:

index - to look up

Returns:

reference to the element

setElementAt

public ReferencePart setElementAt(ReferencePart elem,
                                  int index)

Sets the element at given index to a new element.

Parameters:

elem - element to set to

index - index to set at

Returns:

previous value at given index

lastElement

public ReferencePart lastElement()

Returns last element in reference.

Returns:

last element in reference. Null if none

firstElement

public ReferencePart firstElement()

Returns first element of reference.

Returns:

first element

addElement

public ReferencePart addElement(ReferencePart o)

Adds element to the end of the reference.

Parameters:

o - reference part to add

Returns:

part that was added

addElements

public Reference addElements(Reference ref)

Adds a reference to the end of the reference. ReferenceParts in the given reference are NOT copied.

Parameters:

ref - of elements to be added

Returns:

Reference reference that was added to this one

removeElement

public boolean removeElement(ReferencePart o)

Remove element from reference.

Parameters:

o - to remove from reference

Returns:

true if element there and removed, false otherwise

resolve

public java.lang.Object resolve(ReferenceResolver rr,
                                int index)
                         throws SmartFrogResolutionException

Resolves this reference using the given reference resolver, and starting at index of this reference. If the reference size is 0 the given reference resolver is returned.

Parameters:

rr - ReferenceResolver to be used for resolving this reference

index - index of first referencepart to start resolving at

Returns:

attribute found on resolving this reference

Throws:

SmartFrogResolutionException - reference failed to resolve

resolve

public java.lang.Object resolve(RemoteReferenceResolver rr,
                                int index)
                         throws SmartFrogResolutionException

Resolves this reference using the given remote reference resolver, and starting at index of this reference. If the reference size is 0 the given reference resolver is returned.

Parameters:

rr - ReferenceResolver to be used for resolving this reference

index - index of first referencepart to start resolving at

Returns:

attribute found on resolving this reference

Throws:

SmartFrogResolutionException - if reference failed to resolve

toString

public java.lang.String toString()

Returns string representation of the reference. Overrides Object.toString.

Overrides:

toString in class java.lang.Object

Returns:

String representing the reference