org.apache.turbine.modules
Class ScreenLoader

java.lang.Object
  |
  +--java.util.Dictionary
        |
        +--java.util.Hashtable
              |
              +--org.apache.turbine.modules.GenericLoader
                    |
                    +--org.apache.turbine.modules.ScreenLoader
All Implemented Interfaces:
java.lang.Cloneable, java.util.Map, java.io.Serializable

public class ScreenLoader
extends GenericLoader

The purpose of this class is to allow one to load and execute Screen modules.

Version:
$Id: ScreenLoader.java,v 1.1.1.1 2001/08/16 05:08:31 jvanzyl Exp $
Author:
Dave Bryson
See Also:
Serialized Form

Inner classes inherited from class java.util.Map
java.util.Map.Entry
 
Field Summary
private static ScreenLoader instance
          The single instance of this class.
 
Fields inherited from class org.apache.turbine.modules.GenericLoader
CACHE, reload, TURBINE_PACKAGE
 
Fields inherited from class java.util.Hashtable
count, emptyEnumerator, emptyIterator, ENTRIES, entrySet, KEYS, keySet, loadFactor, modCount, serialVersionUID, table, threshold, values, VALUES
 
Constructor Summary
private ScreenLoader()
          These ctor's are private to force clients to use getInstance() to access this class.
private ScreenLoader(int i)
          These ctor's are private to force clients to use getInstance() to access this class.
 
Method Summary
private  void addInstance(java.lang.String name, Screen screen)
          Adds an instance of an object into the hashtable.
 org.apache.ecs.ConcreteElement eval(RunData data, java.lang.String name)
          Attempts to load and execute the external Screen.
 void exec(RunData data, java.lang.String name)
          Attempts to load and execute the Screen.
static ScreenLoader getInstance()
          The method through which this class is accessed.
 Screen getInstance(java.lang.String name)
          Pulls out an instance of the object by name.
 
Methods inherited from class org.apache.turbine.modules.GenericLoader
cache, getBasePackage, reload, setReload
 
Methods inherited from class java.util.Hashtable
, clear, clone, contains, containsKey, containsValue, elements, entrySet, equals, get, getEnumeration, getIterator, hashCode, isEmpty, keys, keySet, put, putAll, readObject, rehash, remove, size, toString, values, writeObject
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, registerNatives, wait, wait, wait
 

Field Detail

instance

private static ScreenLoader instance
The single instance of this class.
Constructor Detail

ScreenLoader

private ScreenLoader()
These ctor's are private to force clients to use getInstance() to access this class.

ScreenLoader

private ScreenLoader(int i)
These ctor's are private to force clients to use getInstance() to access this class.
Method Detail

addInstance

private void addInstance(java.lang.String name,
                         Screen screen)
Adds an instance of an object into the hashtable.
Parameters:
name - Name of object.
screen - Screen to be associated with name.

eval

public org.apache.ecs.ConcreteElement eval(RunData data,
                                           java.lang.String name)
                                    throws java.lang.Exception
Attempts to load and execute the external Screen. This is used when you want to execute a Screen which returns its output via a MultiPartElement instead of out the data.getPage() value. This allows you to easily chain the execution of Screen modules together.
Parameters:
data - Turbine information.
name - Name of object that will execute the screen.
Throws:
java.lang.Exception - a generic exception.

exec

public void exec(RunData data,
                 java.lang.String name)
          throws java.lang.Exception
Attempts to load and execute the Screen. This is used when you want to execute a Screen which returns its output via the data.getPage() object.
Overrides:
exec in class GenericLoader
Parameters:
data - Turbine information.
name - Name of object that will execute the screen.
Throws:
java.lang.Exception - a generic exception.

getInstance

public Screen getInstance(java.lang.String name)
                   throws java.lang.Exception
Pulls out an instance of the object by name. Name is just the single name of the object.
Parameters:
name - Name of object instance.
Returns:
A Screen with the specified name, or null.
Throws:
java.lang.Exception - a generic exception.

getInstance

public static ScreenLoader getInstance()
The method through which this class is accessed.
Returns:
The single instance of this class.


Copyright © 2000-2002 Apache Software Foundation. All Rights Reserved.