com.softwareag.mobile.runtime.toolkit.util

Class ContextKeyStore

java.lang.Object

com.softwareag.mobile.runtime.toolkit.util.Observable

com.softwareag.mobile.runtime.toolkit.util.ContextKeyStore

All Implemented Interfaces:

IDatasource

public final class ContextKeyStore
extends Observable
implements IDatasource

The ContextKeyStore is used to store and access objects in the application context. Each object is identified by a String key. Use store() to make the current state persistent across new start of the application. The latest state is automatically restored when accessed the first time.

This class is not meant to be extended.

Version:

10.3.0.0002-0443

Method Summary

Modifier and Type	Method and Description
void	clear() Clears the ContextKeyStore and removes all objects and keys.
static java.lang.Object	get(java.lang.String key) Registers a new key value pair.
java.lang.Object	getExpressionValue(java.lang.String rootExpression) This method is used to retrieve an object from the data model using an expression. An expression can be any String an IDatasource implementation uses to reference an object.
static ContextKeyStore	getInstance() Get the shared instance of ContextKeyStore.
static boolean	remove(java.lang.String key) Removes the value for passed key.
static java.lang.String	resolve(java.lang.String text) Replaces tokens identified by {, } (mainly context keys) with the correspond values.
boolean	restore() Loads all the keys and it's values stored with store() and restores the state of the context to the state when it was last saved.
static void	set(java.lang.String key, java.lang.Object value) Sets the value for a specific key.
static void	setDefaultValues(java.util.Hashtable d) Sets the default values to be used if no value has been set for a key.
void	setExpressionValue(java.lang.String rootExpression, java.lang.Object value) This method is used to update an object in the data model. An expression can be any String an IDatasource implementation uses to reference an object.
void	store() Saves all keys and it's values into a persistent RecordStore.

Methods inherited from class com.softwareag.mobile.runtime.toolkit.util.Observable

addObserver, deleteObserver, notifyObservers, notifyObservers

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static ContextKeyStore getInstance()

Get the shared instance of ContextKeyStore.

Returns:

getExpressionValue

public java.lang.Object getExpressionValue(java.lang.String rootExpression)
                                    throws java.lang.Exception

Description copied from interface: IDatasource

This method is used to retrieve an object from the data model using an expression.
An expression can be any String an IDatasource implementation uses to reference an object.

Specified by:

getExpressionValue in interface IDatasource

Parameters:

rootExpression - String that references an object in the data model

Returns:

the object for the given expression or null if there was no object

Throws:

java.lang.Exception - if an error occured evaluating the given expression

setExpressionValue

public void setExpressionValue(java.lang.String rootExpression,
                               java.lang.Object value)
                        throws java.lang.Exception

Description copied from interface: IDatasource

This method is used to update an object in the data model.
An expression can be any String an IDatasource implementation uses to reference an object.

Specified by:

setExpressionValue in interface IDatasource

Parameters:

rootExpression - String that references an object in the data model

value - new object value for the given expression

Throws:

java.lang.Exception - if an error occured evaluating the given expression

setDefaultValues

public static void setDefaultValues(java.util.Hashtable d)

Sets the default values to be used if no value has been set for a key. You might need to make sure to call before the context is accessed for the first time.

Parameters:

d - a Hashtable with key and values used as default values

restore

public boolean restore()

Loads all the keys and it's values stored with store() and restores the state of the context to the state when it was last saved. After the restore, only the keys from the store will be available in the context. If you call restore() all changes since the last call of store() will be lost!

Currently only Integer, Boolean and String value types are supported.

Returns:

true if the data was restored successfully

store

public void store()

Saves all keys and it's values into a persistent RecordStore. Use restore() to load the data, even after restart of the application.

Currently only Integer, Boolean and String value types are supported. All other keys and it's values will not be stored!

clear

public void clear()

Clears the ContextKeyStore and removes all objects and keys.

set

public static void set(java.lang.String key,
                       java.lang.Object value)

Sets the value for a specific key. Both, key and value, must not be null.

Parameters:

key -

value -

get

public static java.lang.Object get(java.lang.String key)

Registers a new key value pair.
Both key and value must not be null.

Parameters:

key - the key to identify the value

remove

public static boolean remove(java.lang.String key)

Removes the value for passed key.

Parameters:

key - the key to identify the value

Returns:

Returns true if the value could be removed, false otherwise

resolve

public static java.lang.String resolve(java.lang.String text)

Replaces tokens identified by {, } (mainly context keys) with the correspond values.

Parameters:

text - the text value which needs to be resolved

Returns:

Returns the text with replaced context key values