org.mmbase.bridge.implementation
Class BasicNodeManager

java.lang.Object
  |
  +--org.mmbase.bridge.implementation.BasicNodeManager

All Implemented Interfaces:

java.lang.Comparable, NodeManager

Direct Known Subclasses:

BasicRelationManager, VirtualNodeManager

public class BasicNodeManager

extends java.lang.Object

implements NodeManager, java.lang.Comparable

This class represents a node's type information object - what used to be the 'builder'. It contains all the field and attribuut information, as well as GUI data for editors and some information on deribed and deriving types. It also contains some maintenance code - code to create new nodes, en code to query objects belonging to the same manager. Since node types are normally maintained through use of config files (and not in the database), as wel as for security issues, the data of a nodetype cannot be changed except through the use of an administration module (which is why we do not include setXXX methods here).

Version:

$Id: BasicNodeManager.java,v 1.29 2002/01/31 10:05:12 pierre Exp $

Author:

Rob Vermeulen, Pierre van Rooden

Field Summary

protected MMObjectBuilder	builder
protected BasicCloud	cloud
protected java.util.Hashtable	fieldTypes

Fields inherited from interface org.mmbase.bridge.NodeManager

ORDER_CREATE, ORDER_EDIT, ORDER_LIST, ORDER_SEARCH

Method Summary

int	compareTo(java.lang.Object o) Compares two nodemanagers for sorting.
Node	createNode() Creates a new node.
boolean	equals(java.lang.Object o) Compares two nodemanagers, and returns true if they are equal.
Cloud	getCloud() Returns the cloud to which this manager belongs.
java.lang.String	getDescription() Returns the description of this node manager.
Field	getField(java.lang.String fieldName) Returns the field with the specified name.
FieldList	getFields() Returns a list of all fields defined for this node manager.
FieldList	getFields(int order) Retrieve a subset of field types of this NodeManager, depending on a given order.
java.lang.String	getGUIName() Returns the descriptive name of this node manager.
java.lang.String	getInfo(java.lang.String command) Retrieve info from a node manager based on a command string.
java.lang.String	getInfo(java.lang.String command, org.mmbase.bridge.implementation.ServletRequest req, org.mmbase.bridge.implementation.ServletResponse resp)
NodeList	getList(java.lang.String command, java.util.Hashtable parameters) Retrieve info (as a list of virtual nodes) from a node manager based on a command string.
NodeList	getList(java.lang.String command, java.util.Hashtable parameters, org.mmbase.bridge.implementation.ServletRequest req, org.mmbase.bridge.implementation.ServletResponse resp)
NodeList	getList(java.lang.String constraints, java.lang.String orderby, java.lang.String directions) Returns a list of nodes belonging to this node manager.
java.lang.String	getName() Returns the name of this node manager.
int	hashCode() Returns the nodemanager's hashCode.
protected void	init(MMObjectBuilder builder, Cloud cloud)
boolean	mayCreateNode() Check if the current user may create a new node of this type.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.mmbase.bridge.NodeManager

getInfo, getList

Field Detail

cloud

protected BasicCloud cloud

builder

protected MMObjectBuilder builder

fieldTypes

protected java.util.Hashtable fieldTypes

Method Detail

init

protected void init(MMObjectBuilder builder,
                    Cloud cloud)

createNode

public Node createNode()

Description copied from interface: NodeManager

Creates a new node. The returned node will not be visible in the cloud until the commit() method is called on this node. Until then it will have a temporary node number.

Specified by:

createNode in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

the new Node

getCloud

public Cloud getCloud()

Description copied from interface: NodeManager

Returns the cloud to which this manager belongs.

Specified by:

getCloud in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

the cloud to which this manager belongs

getName

public java.lang.String getName()

Description copied from interface: NodeManager

Returns the name of this node manager. This name is a unique name.

Specified by:

getName in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

the name of this node manager.

getGUIName

public java.lang.String getGUIName()

Description copied from interface: NodeManager

Returns the descriptive name of this node manager. This name will be in the default language (defined in mmbaseroot.xml).

Specified by:

getGUIName in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

the descriptive name of this node manager

getDescription

public java.lang.String getDescription()

Description copied from interface: NodeManager

Returns the description of this node manager.

Specified by:

getDescription in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

the description of this node manager

getFields

public FieldList getFields()

Description copied from interface: NodeManager

Returns a list of all fields defined for this node manager.

Specified by:

getFields in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

a list of all fields defined for this node manager

getFields

public FieldList getFields(int order)

Description copied from interface: NodeManager

Retrieve a subset of field types of this NodeManager, depending on a given order.

Specified by:

getFields in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Parameters:

order - the order in which to list the fields

Returns:

a List of FieldType objects

getField

public Field getField(java.lang.String fieldName)

Description copied from interface: NodeManager

Returns the field with the specified name.

Specified by:

getField in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Parameters:

name - the name of the field to be returned

Returns:

the field with the requested name

getList

public NodeList getList(java.lang.String constraints,
                        java.lang.String orderby,
                        java.lang.String directions)

Description copied from interface: NodeManager

Returns a list of nodes belonging to this node manager. Constraints can be given to exclude nodes from the returned list. These constraints follow the syntax of the SQL where clause. It's a good practice to use uppercase letters for the operators and lowercase letters for the fieldnames. Example constraints are:

 "number = 100" (!=, <, >, <= and >= can also be used)
 "name = 'admin'",
 "email IS NULL" (indicating the email field is empty)
 "email LIKE '%.org'" (indication the email should end with .org)
 "number BETWEEN 99 AND 101"
 "name IN ('admin', 'anonymous')"
 

The NOT operator can be used to get the opposite result like:

 "NOT (number = 100)"
 "NOT (name = 'admin')",
 "email IS NOT NULL"
 "email NOT LIKE '%.org'" (indication the email should not end with .org)
 "number NOT BETWEEN 99 AND 101"
 "name NOT IN ('admin', 'anonymous')"
 

Some special functions (not part of standard SQL, but most databases support them) can be used like:

 "LOWER(name) = 'admin'" (to also allow 'Admin' to be selected)
 "LENGTH(name) > 5" (to only select names longer then 5 characters)
 

Constraints can be linked together using AND and OR:

 "((number=100) OR (name='admin') AND email LIKE '%.org')"
 

The single quote can be escaped using it twice for every single occurence:

 "name='aaa''bbb'" (if we want to find the string aaa'bbb)
 

For more info consult a SQL tutorial like this one.

Specified by:

getList in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Parameters:

constraints - Contraints to prevent nodes from being included in the resulting list which would normally by included or null if no contraints should be applied .

orderby - A comma separated list of field names on which the returned list should be sorted or null if the order of the returned virtual nodes doesn't matter.

directions - A comma separated list of values indicating wether to sort up (ascending) or down (descending) on the corresponding field in the orderby parameter or null if sorting on all fields should be up. The value DOWN (case insensitive) indicates that sorting on the corresponding field should be down, all other values (including the empty value) indicate that sorting on the corresponding field should be up. If the number of values found in this parameter are less than the number of fields in the orderby parameter, all fields that don't have a corresponding direction value are sorted according to the last specified direction value.

Returns:

a list of nodes belonging to this node manager

getInfo

public java.lang.String getInfo(java.lang.String command)

Description copied from interface: NodeManager

Retrieve info from a node manager based on a command string. Similar to the $MOD command in SCAN.

Specified by:

getInfo in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Parameters:

command - the info to obtain, i.e. "USER-OS".

getInfo

public java.lang.String getInfo(java.lang.String command,
                                org.mmbase.bridge.implementation.ServletRequest req,
                                org.mmbase.bridge.implementation.ServletResponse resp)

getList

public NodeList getList(java.lang.String command,
                        java.util.Hashtable parameters)

Description copied from interface: NodeManager

Retrieve info (as a list of virtual nodes) from a node manager based on a command string. Similar to the LIST command in SCAN. The values retrieved are represented as fields of a virtual node, named following the fieldnames listed in the fields paramaters..

Specified by:

getList in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Parameters:

command - the info to obtain, i.e. "USER-OS".

parameters - a hashtable containing the named parameters of the list.

getList

public NodeList getList(java.lang.String command,
                        java.util.Hashtable parameters,
                        org.mmbase.bridge.implementation.ServletRequest req,
                        org.mmbase.bridge.implementation.ServletResponse resp)

equals

public boolean equals(java.lang.Object o)

Compares two nodemanagers, and returns true if they are equal. This effectively means that both objects are nodemanagers, and they both use to the same builder type

Overrides:

equals in class java.lang.Object

Parameters:

o - the object to compare it with

compareTo

public int compareTo(java.lang.Object o)

Compares two nodemanagers for sorting. It uses the GUIName for sorting, which makes the sorting alphabetic. This is what you need when you e.g. try to make an generic editor.

Specified by:

compareTo in interface java.lang.Comparable

Parameters:

o - the object to compare with

hashCode

public int hashCode()

Returns the nodemanager's hashCode. This effectively returns the buidlers's object type number

Overrides:

hashCode in class java.lang.Object

mayCreateNode

public boolean mayCreateNode()

Description copied from interface: NodeManager

Check if the current user may create a new node of this type.

Specified by:

mayCreateNode in interface NodeManager

Following copied from interface: org.mmbase.bridge.NodeManager

Returns:

Check if the current user may create a new node of this type.