org.mmbase.bridge.jsp.taglib
Class AbstractNodeListTag

org.mmbase.bridge.jsp.taglib.AbstractNodeListTag

All Implemented Interfaces:

ListProvider, TagIdentifier

Direct Known Subclasses:

ListNodesTag, ListRelationsTag, ListTag, RelatedNodesTag, TreeTag, WhoTag

public abstract class AbstractNodeListTag

implements ListProvider

AbstractNodeListTag, provides basic functionality for listing objects stored in MMBase

Author:

Kees Jongenburger, Michiel Meeuwissen, Pierre van Rooden

Field Summary

protected boolean	changed Determines whether a field in orderby changed during iteration.
protected java.lang.String	constraints Holds the clause used to filter the list.
protected int	currentItemIndex The current item
protected java.lang.String	directions Holds the direction to sort the list on (per field in orderby).
protected int	max The maximum number of elements in a list.
protected static int	NOT_HANDLED
protected int	offset The offset of the elements that are returned in a list.
protected java.lang.String	orderby Holds the list of fields to sort the list on.
protected NodeList	returnList
protected NodeIterator	returnValues Data member to hold an iteration of the values to return.
protected int	timerHandle A handle necessary when using the Time Tag;

Constructor Summary

AbstractNodeListTag()

Method Summary

int	doAfterBody()
int	doEndTag()
void	doInitBody()
protected int	doStartTagHelper()
java.lang.Object	getCurrent()
int	getIndex()
boolean	isChanged() If you order a list, then the 'changed' property will be true if the field on which you order changed value.
void	setConstraints(java.lang.String where) Sets the selection query
void	setDirections(java.lang.String directions) Sets the direction to sort on
void	setMax(java.lang.String m) Set the list maximum
void	setOffset(java.lang.String o) Set the list offset
void	setOrderby(java.lang.String orderby) Sets the fields to sort on.
protected int	setReturnValues(NodeList nodes) Creates the node iterator and sets appropriate variables (i.e.
protected int	setReturnValues(NodeList nodes, boolean trim) Creates the node iterator and sets appropriate variables (i.e.
int	size()

Methods inherited from interface org.mmbase.bridge.jsp.taglib.TagIdentifier

getId

Field Detail

orderby

protected java.lang.String orderby

Holds the list of fields to sort the list on. The sort itself is implementation specific.

directions

protected java.lang.String directions

Holds the direction to sort the list on (per field in orderby). The sort itself is implementation specific.

constraints

protected java.lang.String constraints

Holds the clause used to filter the list. This is either a SQL-clause, with MMBase fields in brackets, a altavista-like search, preceded with the keyword ALTA, or a MMBase database node search, preceded with the keyord MMNODE. The filter itself is implementation specific (not all lists may implement this!).

max

protected int max

The maximum number of elements in a list. Setting the list size to conform to this maximum is implementation specific.

offset

protected int offset

The offset of the elements that are returned in a list. Setting the list to conform to this ofsset is implementation specific.

changed

protected boolean changed

Determines whether a field in orderby changed during iteration.

returnValues

protected NodeIterator returnValues

Data member to hold an iteration of the values to return. This variable is set in setReturnValues(NodeList), which should be called from #doStartTag, and will be used to fill the return variables for every iteration.

returnList

protected NodeList returnList

currentItemIndex

protected int currentItemIndex

The current item

timerHandle

protected int timerHandle

A handle necessary when using the Time Tag;

NOT_HANDLED

protected static int NOT_HANDLED

Constructor Detail

AbstractNodeListTag

public AbstractNodeListTag()

Method Detail

getIndex

public int getIndex()

Specified by:

getIndex in interface ListProvider

Following copied from interface: org.mmbase.bridge.jsp.taglib.ListProvider

Returns:

the index of the current item in a list

getCurrent

public java.lang.Object getCurrent()

Specified by:

getCurrent in interface ListProvider

Following copied from interface: org.mmbase.bridge.jsp.taglib.ListProvider

Returns:

the current item in a list

setOrderby

public void setOrderby(java.lang.String orderby)
                throws javax.servlet.jsp.JspTagException

Sets the fields to sort on.

Parameters:

sorted - A comma separated list of fields on witch the returned nodes should be sorted

setDirections

public void setDirections(java.lang.String directions)
                   throws javax.servlet.jsp.JspTagException

Sets the direction to sort on

Parameters:

direction - the selection query for the object we are looking for direction

setMax

public void setMax(java.lang.String m)
            throws javax.servlet.jsp.JspTagException

Set the list maximum

Parameters:

max - the max number of values returned

setOffset

public void setOffset(java.lang.String o)
               throws javax.servlet.jsp.JspTagException

Set the list offset

Parameters:

max - the max number of values returned

setConstraints

public void setConstraints(java.lang.String where)
                    throws javax.servlet.jsp.JspTagException

Sets the selection query

Parameters:

where - the selection query

doStartTagHelper

protected int doStartTagHelper()
                        throws javax.servlet.jsp.JspTagException

setReturnValues

protected int setReturnValues(NodeList nodes)
                       throws javax.servlet.jsp.JspTagException

Creates the node iterator and sets appropriate variables (i.e. listsize) froma passed node list. The list is assumed to be already sorted and trimmed.

Parameters:

nodes - the nodelist to create the iterator from

Returns:

EVAL_BODY_TAG if the resulting list is not empty, SKIP_BODY if the list is empty. THis value should be passed as the result of {

setReturnValues

protected int setReturnValues(NodeList nodes,
                              boolean trim)
                       throws javax.servlet.jsp.JspTagException

Creates the node iterator and sets appropriate variables (i.e. listsize). Takes a node list, and trims it using the offset and max attributes if so indicated. The list is assumed to be already sorted.

Parameters:

nodes - the nodelist to create the iterator from

trim - if true, trim the list using offset and max (if false, it is assumed the calling routine already did so)

Returns:

EVAL_BODY_TAG if the resulting list is not empty, SKIP_BODY if the list is empty. THis value should be passed as the result of {

doAfterBody

public int doAfterBody()
                throws javax.servlet.jsp.JspTagException

doEndTag

public int doEndTag()
             throws javax.servlet.jsp.JspTagException

doInitBody

public void doInitBody()
                throws javax.servlet.jsp.JspTagException

isChanged

public boolean isChanged()

If you order a list, then the 'changed' property will be true if the field on which you order changed value.

Specified by:

isChanged in interface ListProvider

Following copied from interface: org.mmbase.bridge.jsp.taglib.ListProvider

Returns:

a boolean indicating wether the field on which was sorted is changed.

size

public int size()

Specified by:

size in interface ListProvider

Following copied from interface: org.mmbase.bridge.jsp.taglib.ListProvider

Returns:

the size of the list