org.apache.directory.server.core.api.normalization

Class FilterNormalizingVisitor

java.lang.Object

org.apache.directory.server.core.api.normalization.FilterNormalizingVisitor

All Implemented Interfaces:

org.apache.directory.api.ldap.model.filter.FilterVisitor

public class FilterNormalizingVisitor
extends Object
implements org.apache.directory.api.ldap.model.filter.FilterVisitor

A filter visitor which normalizes leaf node values as it visits them. It also removes leaf nodes from branches whose attributeType is undefined. It obviously cannot remove a leaf node from a filter which is only a leaf node. Checks to see if a filter is a leaf node with undefined attributeTypes should be done outside this visitor. Since this visitor may remove filter nodes it may produce negative results on filters, like NOT branch nodes without a child or AND and OR nodes with one or less children. This might make some partition implementations choke. To avoid this problem we clean up branch nodes that don't make sense. For example all BranchNodes without children are just removed. An AND and OR BranchNode with a single child is replaced with it's child for all but the topmost branch node which we cannot replace. So again the top most branch node must be inspected by code outside of this visitor.

Author:

Apache Directory Project

Constructor Summary

Constructors

Constructor and Description
FilterNormalizingVisitor(org.apache.directory.api.ldap.model.schema.normalizers.NameComponentNormalizer ncn, org.apache.directory.api.ldap.model.schema.SchemaManager schemaManager) Creates a new instance of NormalizingVisitor.

Method Summary

Modifier and Type	Method and Description
boolean	canVisit(org.apache.directory.api.ldap.model.filter.ExprNode node)
List<org.apache.directory.api.ldap.model.filter.ExprNode>	getOrder(org.apache.directory.api.ldap.model.filter.BranchNode node, List<org.apache.directory.api.ldap.model.filter.ExprNode> children)
static boolean	isFilterChar(char c) Check if the given char is a filter escaped char <filterEscapedChars> ::= '\0' | '(' | ')' | '*' | '\'
boolean	isPrefix()
Object	visit(org.apache.directory.api.ldap.model.filter.ExprNode node) Visit the tree, normalizing the leaves and recusrsively visit the branches.

Methods inherited from class java.lang.Object

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

Constructor Detail

FilterNormalizingVisitor

public FilterNormalizingVisitor(org.apache.directory.api.ldap.model.schema.normalizers.NameComponentNormalizer ncn,
                                org.apache.directory.api.ldap.model.schema.SchemaManager schemaManager)

Creates a new instance of NormalizingVisitor.

Parameters:

ncn - The name component normalizer to use

schemaManager - The schemaManager

Method Detail

isFilterChar

public static boolean isFilterChar(char c)

Check if the given char is a filter escaped char <filterEscapedChars> ::= '\0' | '(' | ')' | '*' | '\'

Parameters:

c - the char we want to test

Returns:

true if the char is a pair char only

visit

public Object visit(org.apache.directory.api.ldap.model.filter.ExprNode node)

Visit the tree, normalizing the leaves and recusrsively visit the branches. Here are the leaves we are visiting : - PresenceNode ( attr =* ) - ExtensibleNode ( ? ) - SubStringNode ( attr = *X*Y* ) - ApproximateNode ( attr ~= value ) - EqualityNode ( attr = value ) - GreaterEqNode ( attr >= value ) - LessEqNode ( attr <= value ) The PresencNode is managed differently from other nodes, as it just check for the attribute, not the value.

Specified by:

visit in interface org.apache.directory.api.ldap.model.filter.FilterVisitor

Parameters:

node - the node to visit

Returns:

the visited node

canVisit

public boolean canVisit(org.apache.directory.api.ldap.model.filter.ExprNode node)

Specified by:

canVisit in interface org.apache.directory.api.ldap.model.filter.FilterVisitor

isPrefix

public boolean isPrefix()

Specified by:

isPrefix in interface org.apache.directory.api.ldap.model.filter.FilterVisitor

getOrder

public List<org.apache.directory.api.ldap.model.filter.ExprNode> getOrder(org.apache.directory.api.ldap.model.filter.BranchNode node,
                                                                          List<org.apache.directory.api.ldap.model.filter.ExprNode> children)

Specified by:

getOrder in interface org.apache.directory.api.ldap.model.filter.FilterVisitor