org.hibernate.ogm.datastore.neo4j.query.parsing.impl

Class AliasResolver

java.lang.Object

org.hibernate.ogm.datastore.neo4j.query.parsing.impl.AliasResolver

public class AliasResolver
extends Object

Keep track of the aliases needed to create the Cypher query.

Author:

Davide D'Alto

Constructor Summary

Constructors

Constructor and Description
AliasResolver()

Method Summary

Modifier and Type	Method and Description
String	createAliasForEmbedded(String entityAlias, List<String> propertyPathWithoutAlias, boolean optionalMatch) Given the path to an embedded property, it will create an alias to use in the query for the embedded containing the property.
String	findAliasForEmbedded(String entityAlias, List<String> propertyPathWithoutAlias) Given the alias of the entity and the path to the embedded properties it will return the alias of the embedded component containing the property.
String	findAliasForType(String entityType)
EmbeddedAliasTree	getAliasTree(String entityAlias) Given the alias of the entity it will return a tree structure containing all the aliases for the embedded properties of the entity.
boolean	isOptionalMatch(String alias) Tells if the alias has to be used in the OPTIONAL MATCH part of the query.
void	registerEntityAlias(String entityName, String alias)

Methods inherited from class java.lang.Object

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

Constructor Detail

AliasResolver

public AliasResolver()

Method Detail

registerEntityAlias

public void registerEntityAlias(String entityName,
                                String alias)

findAliasForType

public String findAliasForType(String entityType)

createAliasForEmbedded

public String createAliasForEmbedded(String entityAlias,
                                     List<String> propertyPathWithoutAlias,
                                     boolean optionalMatch)

Given the path to an embedded property, it will create an alias to use in the query for the embedded containing the property.

The alias will be saved and can be returned using the method findAliasForEmbedded(String, List).

For example, using n as entity alias and [embedded, anotherEmbedded, property] as path to the property will return "n_2" as alias for "n.embedded.anotherEmbedded".

Parameters:

entityAlias - the alias of the entity that contains the embedded

propertyPathWithoutAlias - the path to the property without the alias

optionalMatch - if true, the alias does not represetn a required match in the query (It will appear in the OPTIONAL MATCH clause)

Returns:

the alias of the embedded containing the property

findAliasForEmbedded

public String findAliasForEmbedded(String entityAlias,
                                   List<String> propertyPathWithoutAlias)

Given the alias of the entity and the path to the embedded properties it will return the alias of the embedded component containing the property.

Parameters:

entityAlias - the alias of the entity that contains the embedded

propertyPathWithoutAlias - the path to the property without the alias

Returns:

the alias of the embedded containing the property or null

See Also:

createAliasForEmbedded(String, List, boolean)

getAliasTree

public EmbeddedAliasTree getAliasTree(String entityAlias)

Given the alias of the entity it will return a tree structure containing all the aliases for the embedded properties of the entity.

The tree has the entity alias as root and the embedded alias as children. For example, a path to two properties like:

1. n.first.anotherEmbedded
2. n.second.anotherEmbedded

Might be represented with the following structure:

 n (alias = n)|- first (alias = _n1)  -- anotherEmbedded (alias = _n2)
              |
              -- second (alias = _n3) -- anotherEmbedded (alias = _n4)
 

Parameters:

entityAlias - the alias of the entity that contains the embedded

Returns:

the corresponding EmbeddedAliasTree or null

isOptionalMatch

public boolean isOptionalMatch(String alias)

Tells if the alias has to be used in the OPTIONAL MATCH part of the query.

Parameters:

alias - the alis to check

Returns:

true if the alias should be used in OPTIONAL MATCH part of the query, false otherwise