ome.util

Class ContextFilter

java.lang.Object

ome.util.ContextFilter

All Implemented Interfaces:

Filter

Direct Known Subclasses:

ModelMapper, ProxyCleanupFilter, ProxySafeFilter, RdfPrinter, UpdateFilter

public class ContextFilter
extends Object
implements Filter

modified (hierarchical) visitor pattern. See http://c2.com/cgi/wiki?HierarchicalVisitorPattern for more information. (A better name may be "contextual visitor pattern" for graph traversing.) The modifications to Visitor make use of a model graph (here: the ome generated model classes) implementing Filterable. As documented in Filterable, model objects are responsible for calling filter.filter(someField) for all fields and setting the value of that field to the return value of the method call. The Filter itself is responsible for returning a compatible object and (optionally) stepping into objects and keeping up with context. Note: This class is not thread-safe. template method to filter domain objects. The standard idiom is: if (m != null && hasntSeen(m)){ enter(m); // Provides context addSeen(m); // Prevents looping m.acceptFilter(this); // Visits all fields exit(m); // Remove from context } Implementation notes: - nulls are already "seen"

Field Summary

Fields

Modifier and Type	Field and Description
protected Map	_cache
protected LinkedList	_context

Constructor Summary

Constructors

Constructor and Description
ContextFilter()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	addSeen(Object o)
protected void	afterFilter(String fieldId, Object o)
protected void	beforeFilter(String fieldId, Object o)
Object	currentContext()
protected void	doFilter(String fieldId, Collection c)
protected void	doFilter(String fieldId, Filterable f)
protected void	doFilter(String fieldId, Object o)
boolean	enter(Object o)
boolean	exit(Object o)
Collection	filter(String fieldId, Collection c) iterates over the contents of the collection and filters each.
protected ome.util.ContextFilter.Entry	filter(String fieldId, ome.util.ContextFilter.Entry entry) doesn't return a new entry. only changes key and value
Filterable	filter(String fieldId, Filterable f)
Map	filter(String fieldId, Map m) filters both the key and value sets of the map.
Object	filter(String fieldId, Object o) used when type is unknown. this is possibly omittable with generics
protected boolean	hasntSeen(Object o)
protected void	pop(Object o)
Object	previousContext(int index)
protected void	push(Object o)

Methods inherited from class java.lang.Object

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

Field Detail

_cache

protected Map _cache

_context

protected LinkedList _context

Constructor Detail

ContextFilter

public ContextFilter()

Method Detail

beforeFilter

protected void beforeFilter(String fieldId,
                Object o)

doFilter

protected void doFilter(String fieldId,
            Object o)

doFilter

protected void doFilter(String fieldId,
            Filterable f)

doFilter

protected void doFilter(String fieldId,
            Collection c)

afterFilter

protected void afterFilter(String fieldId,
               Object o)

filter

public Filterable filter(String fieldId,
                Filterable f)

Specified by:

filter in interface Filter

filter

public Collection filter(String fieldId,
                Collection c)

iterates over the contents of the collection and filters each. Adds itself to the context. This is somewhat dangerous.

Specified by:

filter in interface Filter

filter

public Map filter(String fieldId,
         Map m)

filters both the key and value sets of the map. Adds itself to the context. Somewhat dangerous.

Specified by:

filter in interface Filter

filter

public Object filter(String fieldId,
            Object o)

used when type is unknown. this is possibly omittable with generics

Specified by:

filter in interface Filter

filter

protected ome.util.ContextFilter.Entry filter(String fieldId,
                                  ome.util.ContextFilter.Entry entry)

doesn't return a new entry. only changes key and value

enter

public boolean enter(Object o)

exit

public boolean exit(Object o)

currentContext

public Object currentContext()

previousContext

public Object previousContext(int index)

push

protected void push(Object o)

pop

protected void pop(Object o)

addSeen

protected void addSeen(Object o)

hasntSeen

protected boolean hasntSeen(Object o)