ContextFunction (Eclipse Platform API Specification)

java.lang.Object
- org.eclipse.e4.core.contexts.ContextFunction

All Implemented Interfaces:

IContextFunction
```
public abstract class ContextFunction
extends Object
implements IContextFunction
```
The base class for all computed value implementations. Clients may subclass this class. See the class comment of IContextFunction for specific rules that must be followed by function implementations.
This class is intended to be subclassed by clients.

Since:

1.3

See Also:

IContextFunction

Field Summary
- Fields inherited from interface org.eclipse.e4.core.contexts.IContextFunction
  SERVICE_CONTEXT_KEY, SERVICE_NAME

Constructor Summary

Constructors
Constructor Description

ContextFunction()
Constructs a new instance of the context function

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`Object`	`compute(IEclipseContext context)`	Deprecated. `IContextFunction`'s compute() was changed to take the context key
`Object`	`compute(IEclipseContext context, String contextKey)`	Evaluates the function based on the provided arguments and context to produce a consistent result.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ContextFunction
```
public ContextFunction()
```
    Constructs a new instance of the context function
- Method Detail
  - compute
```
@Deprecated
public Object compute(IEclipseContext context)
```
    Deprecated.
    IContextFunction's compute() was changed to take the context key
  - compute
```
public Object compute(IEclipseContext context,
                      String contextKey)
```
    Description copied from interface: IContextFunction
    
    Evaluates the function based on the provided arguments and context to produce a consistent result.
    
    Specified by:
    
    compute in interface IContextFunction
    
    Parameters:
    
    context - The context in which to perform the value computation.
    
    contextKey - The context key used to find this function; may be null such as if invoked directly.
    
    Returns:
    
    The concrete value. Implementations may return IInjector.NOT_A_VALUE to cause lookup to continue up the context hierarchy.