uk.co.weft.htform
Class LinkTableWidget

java.lang.Object
  uk.co.weft.htform.ResourceConsumerImpl
      uk.co.weft.domutil.NodeGeneratorImpl
          uk.co.weft.htform.Widget
              uk.co.weft.htform.MenuWidget
                  uk.co.weft.htform.MultiSelectWidget
                      uk.co.weft.htform.ShuffleWidget
                          uk.co.weft.htform.LinkTableWidget

All Implemented Interfaces:

java.lang.Cloneable, NodeGenerator, ResourceConsumer

Direct Known Subclasses:

CompositeStylesheetWidget

public class LinkTableWidget

extends ShuffleWidget

implements NodeGenerator

In some simple database designs many-to-many relationships are represented by simple link tables. This is a widget for editing simple link table relationships. It is not magic, and may not do what you want... Special warning: the default postProcess method smashes and recreates all the relevent entries in the link table each time round, so if there is any useful information held in other fields in the link table this class is not what you want (although you might specialise it). It only makes sense to use one of these in a TableWrapperForm.

Version:

$Revision: 1.19.4.3 $ This revision: $Author: simon $

Author:

Simon Brooke (simon@weft.co.uk)

Field Summary

Fields inherited from class uk.co.weft.htform.ShuffleWidget

doProcessExtension, excludeLabel, includeLabel, preferGracefulDegradeToNetscapeBugs, shuffleScript, unselectedExtension

Fields inherited from class uk.co.weft.htform.MultiSelectWidget

eltTag

Fields inherited from class uk.co.weft.htform.MenuWidget

defaultSize, unsetLabel, UNSETVALUEMAGICTOKEN

Fields inherited from class uk.co.weft.htform.Widget

ACTIONCSSCLASS, akprompt, attrs, CONTEXTATTRIBUTESSUFFIX, cssClass, DANGEROUSCSSCLASS, debug, DEFAULTTOKEN, dflt, form, generateAs, GENERATEASHTML, GENERATEASXFORM, GENERATEASXML, help, HELPTOKEN, immutable, ISIMMUTABLETOKEN, ISMANDATORYTOKEN, mandatory, MANDATORYCSSCLASS, maxVisibleSize, name, NAMETOKEN, OPTIONALCSSCLASS, PREVIOUSVALUESUFFIX, prompt, PROMPTTOKEN, size, SIZETOKEN, type, TYPETOKEN

Fields inherited from class uk.co.weft.domutil.NodeGeneratorImpl

namespaceURI

Fields inherited from class uk.co.weft.htform.ResourceConsumerImpl

resourceBundleName

Fields inherited from interface uk.co.weft.domutil.NodeGenerator

NAMESPACEURIMAGICTOKEN

Fields inherited from interface uk.co.weft.htform.ResourceConsumer

RESOURCEBUNDLEMAGICTOKEN

Constructor Summary

LinkTableWidget(java.lang.String name, java.lang.String prompt, java.lang.String help, boolean mute, int size, java.lang.String near_table, java.lang.String far_table, java.lang.String near_key, java.lang.String far_key, java.lang.String far_ident)
Basic setup -- all the normal widget things, plus a lot more of my own.

LinkTableWidget(java.lang.String name, java.lang.String prompt, java.lang.String help, boolean mute, int size, java.lang.String near_table, java.lang.String far_table, java.lang.String near_key, java.lang.String far_key, java.lang.String far_ident, java.lang.String rank)
Intermediate setup -- basic plus rank.

LinkTableWidget(java.lang.String name, java.lang.String prompt, java.lang.String help, boolean mute, int size, java.lang.String near_table, java.lang.String far_table, java.lang.String near_key, java.lang.String far_key, java.lang.String far_ident, java.lang.String near_link, java.lang.String far_link, java.lang.String rank)
Full setup -- all the normal widget things, plus a lot more of my own.

Method Summary

java.util.Vector	getOptions(Context context) Query the database for my options.
int	getTabPlaces(Context context) Specialisation:
void	layout(Context context, int tabIndex) There's no point in laying out a LinkTableWidget for a record that hasn't yet been created because all attempts to use it will fail.
java.lang.String	onloadRequest(Context context) LinkTableWidgets positively need JavaScript scripts to support them!
protected void	postProcess(Context context) Pull my values out of the link table.
protected void	preProcess(Context context) If I have values passed in, update the link table to reflect them.

Methods inherited from class uk.co.weft.htform.ShuffleWidget

getWidth, layoutSelectedWidget, layoutSelectedWidget, layoutShuffleButton, layoutShuffleButton, layoutUnselectedWidget, layoutUnselectedWidget, scriptRequest

Methods inherited from class uk.co.weft.htform.MultiSelectWidget

getHeight, layoutValue

Methods inherited from class uk.co.weft.htform.MenuWidget

addOption, clone, generateInnerHTML, generateValue, setDebug

Methods inherited from class uk.co.weft.htform.Widget

generate, generateAttributes, generateAttributes, generateHTML, generateHTMLPrompt, generateXML, getContextAttribute, getCssClass, getHelp, getName, getPrompt, getType, init, layout, layout, layout, layoutAttribute, layoutAttributes, makeReady, maybeLayout, maybeLayout, onloadRequest, scriptRequest, setAttribute, setContextAttribute, setCssClass, setDefault, setHelp, setImmutable, setMandatory, setMandatory, setName, setPrompt, setSize, setType

Methods inherited from class uk.co.weft.domutil.NodeGeneratorImpl

getNamespaceURI, setNamespaceURI

Methods inherited from class uk.co.weft.htform.ResourceConsumerImpl

getContextOrResource, getResource, getResourceOrContext, getResourceString, grs, grs

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.co.weft.domutil.NodeGenerator

generate, getName, getNamespaceURI, init, setDebug

Constructor Detail

LinkTableWidget

public LinkTableWidget(java.lang.String name,
                       java.lang.String prompt,
                       java.lang.String help,
                       boolean mute,
                       int size,
                       java.lang.String near_table,
                       java.lang.String far_table,
                       java.lang.String near_key,
                       java.lang.String far_key,
                       java.lang.String far_ident,
                       java.lang.String near_link,
                       java.lang.String far_link,
                       java.lang.String rank)

Full setup -- all the normal widget things, plus a lot more of my own. Conventions: my name is the name of the link table.

Parameters:

name - the name of the link table in the database

near_table - the name of the table on the 'near' side of the join.

far_table - the name of the table on the 'far' side of the join.

near_key - the name of the key field in the near table. It is assumed that a value for this can be found in the context at update time.

far_key - the name of the key field in the far table.

far_ident - the name of a field in the far table which contains user-friendly identifying information (e.g. a name)

near_link - the name of the column in the link table which joins to the nearside key

far_link - the name of the column in the link table which joins to the farside key

rank - the name of the column to order the entries by. If not null, must be the name of an additional integer column in the link table.

LinkTableWidget

public LinkTableWidget(java.lang.String name,
                       java.lang.String prompt,
                       java.lang.String help,
                       boolean mute,
                       int size,
                       java.lang.String near_table,
                       java.lang.String far_table,
                       java.lang.String near_key,
                       java.lang.String far_key,
                       java.lang.String far_ident,
                       java.lang.String rank)

Intermediate setup -- basic plus rank.

Parameters:

name - the name of the link table in the database

near_table - the name of the table on the 'near' side of the join.

far_table - the name of the table on the 'far' side of the join.

near_key - the name of the key field in the near table. The column that joins to this in the link table is assumed to have the same name. It is assumed that a value for this can be found in the context at update time.

far_key - the name of the key field in the far table. The column that joins to this in the link table is assumed to have the same name.

far_ident - the name of a field in the far table which contains user-friendly identifying information (e.g. a name)

rank - the name of the column to order the entries by. If not null, must be the name of an additional integer column in the link table.

LinkTableWidget

public LinkTableWidget(java.lang.String name,
                       java.lang.String prompt,
                       java.lang.String help,
                       boolean mute,
                       int size,
                       java.lang.String near_table,
                       java.lang.String far_table,
                       java.lang.String near_key,
                       java.lang.String far_key,
                       java.lang.String far_ident)

Basic setup -- all the normal widget things, plus a lot more of my own. Conventions: my name is the name of the link table.

Parameters:

name - the name of the link table in the database

near_table - the name of the table on the 'near' side of the join.

far_table - the name of the table on the 'far' side of the join.

near_key - the name of the key field in the near table. The column that joins to this in the link table is assumed to have the same name. It is assumed that a value for this can be found in the context at update time.

far_key - the name of the key field in the far table. The column that joins to this in the link table is assumed to have the same name.

far_ident - the name of a field in the far table which contains user-friendly identifying information (e.g. a name)

Method Detail

getOptions

public java.util.Vector getOptions(Context context)
                            throws javax.servlet.ServletException

Query the database for my options.

Overrides:

getOptions in class MenuWidget

Throws:

javax.servlet.ServletException

preProcess

protected void preProcess(Context context)
                   throws DataStoreException,
                          javax.servlet.ServletException

If I have values passed in, update the link table to reflect them. Functionality here needs to be driven down into dbutil; this is messy and depends on key fields being numeric. TODO: rewrite carefully.

Overrides:

preProcess in class MultiSelectWidget

Throws:

DataStoreException

javax.servlet.ServletException

postProcess

protected void postProcess(Context context)
                    throws DataStoreException,
                           javax.servlet.ServletException

Pull my values out of the link table.

Overrides:

postProcess in class Widget

Throws:

DataStoreException

javax.servlet.ServletException

See Also:

LinkTableWidget

layout

public void layout(Context context,
                   int tabIndex)
            throws DataFormatException,
                   javax.servlet.ServletException,
                   java.io.IOException

There's no point in laying out a LinkTableWidget for a record that hasn't yet been created because all attempts to use it will fail.

Overrides:

layout in class ShuffleWidget

Throws:

DataFormatException

javax.servlet.ServletException

java.io.IOException

getTabPlaces

public int getTabPlaces(Context context)

Specialisation:

Overrides:

getTabPlaces in class ShuffleWidget

Parameters:

context -

Returns:

See Also:

ShuffleWidget.getTabPlaces(uk.co.weft.dbutil.Context)

onloadRequest

public java.lang.String onloadRequest(Context context)
                               throws javax.servlet.ServletException

LinkTableWidgets positively need JavaScript scripts to support them!

Overrides:

onloadRequest in class ShuffleWidget

Throws:

javax.servlet.ServletException