uk.ac.ed.epcc.webapp

Class Feature

java.lang.Object

uk.ac.ed.epcc.webapp.AbstractSetting<java.lang.Boolean>

uk.ac.ed.epcc.webapp.Feature

All Implemented Interfaces:

java.lang.Comparable<Setting>, TypeConverter<java.lang.Boolean,java.lang.String>, Setting<java.lang.Boolean>, Targetted<java.lang.Boolean>

Direct Known Subclasses:

Preference

public class Feature
extends AbstractSetting<java.lang.Boolean>

A Feature represents optional feature in the code. Normally this should be encapsulated as a singleton constant field so we can locate them by reflection and generate on-line documentation. Each Feature object defines a name for the feature a default setting and descriptive documentation. Some legacy features may be generated dynamically so the same feature may be constructed multiple times but Features with the same name should be identical.

Features can be turned on and off using configuration parameters e.g. service.feature.feature-name=true The results are also cached in the AppContext as the same Feature may be queried a large number of times in the same request.

Constructor Summary

Constructors

Constructor and Description
Feature(java.lang.String name)
Feature(java.lang.String name, boolean def, java.lang.String description)

Method Summary

Modifier and Type	Method and Description
static boolean	checkDynamicFeature(AppContext conn, java.lang.String name, boolean def) checks a feature that is only defined by name (ie the name is generated dynamically)
static boolean	checkFeature(AppContext conn, java.lang.String name) Test a feature by name.
java.lang.Boolean	find(java.lang.String o) Find the required object.
protected boolean	getConfigValue(AppContext conn)
java.lang.Boolean	getCurrent(AppContext conn) get the current value of the setting
java.lang.String	getIndex(java.lang.Boolean value) Get the underlying data representation corresponding to the value
ItemInput<java.lang.String,java.lang.Boolean>	getInput(AppContext conn) and Input to select the setting
protected java.lang.String	getTag()
java.lang.Class<java.lang.Boolean>	getTarget() Get the type of the returned object as far as it is known.
java.lang.String	getText(java.lang.Boolean b)
boolean	isDef()
boolean	isEnabled(AppContext conn)
boolean	isEnabled(java.util.Properties prop) query a property bundle not the AppContext.
static void	setTempFeature(AppContext conn, Feature f, boolean val)

Methods inherited from class uk.ac.ed.epcc.webapp.AbstractSetting

equals, findFeatureByName, getDefault, getDescription, getFeatureTable, getKnownFeatures, getName, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.ed.epcc.webapp.Setting

compareTo

Constructor Detail

Feature

public Feature(java.lang.String name,
               boolean def,
               java.lang.String description)

Feature

public Feature(java.lang.String name)

Method Detail

isDef

public final boolean isDef()

isEnabled

public boolean isEnabled(AppContext conn)

getConfigValue

protected boolean getConfigValue(AppContext conn)

getTag

protected java.lang.String getTag()

isEnabled

public boolean isEnabled(java.util.Properties prop)

query a property bundle not the AppContext. The result is NOT cached.

Parameters:

prop -

Returns:

boolean

checkFeature

public static boolean checkFeature(AppContext conn,
                                   java.lang.String name)

Test a feature by name. This is needed for testing pre-requisite features specified in a config file but will always return false until the class that actually defines the feature is loaded.

Parameters:

conn -

name -

Returns:

checkDynamicFeature

public static boolean checkDynamicFeature(AppContext conn,
                                          java.lang.String name,
                                          boolean def)

checks a feature that is only defined by name (ie the name is generated dynamically)

Parameters:

conn -

name -

Returns:

setTempFeature

public static void setTempFeature(AppContext conn,
                                  Feature f,
                                  boolean val)

getInput

public ItemInput<java.lang.String,java.lang.Boolean> getInput(AppContext conn)

Description copied from interface: Setting

and Input to select the setting

Returns:

getCurrent

public java.lang.Boolean getCurrent(AppContext conn)

Description copied from interface: Setting

get the current value of the setting

Parameters:

conn - AppContext

Returns:

getText

public java.lang.String getText(java.lang.Boolean b)

Overrides:

getText in class AbstractSetting<java.lang.Boolean>

find

public java.lang.Boolean find(java.lang.String o)

Description copied from interface: TypeConverter

Find the required object.

Parameters:

o - Value of the database field

Returns:

Target value or null if invalid

getIndex

public java.lang.String getIndex(java.lang.Boolean value)

Description copied from interface: TypeConverter

Get the underlying data representation corresponding to the value

Returns:

Field value or null if invalid

getTarget

public java.lang.Class<java.lang.Boolean> getTarget()

Description copied from interface: Targetted

Get the type of the returned object as far as it is known. Normally this should be the erasure type corresponding to T.

Returns:

Class object for return type