com.bea.wlpi.common.plugin
Interface PluginField
- All Superinterfaces:
- java.io.Serializable
- public interface PluginField
- extends java.io.Serializable
The interface that a plugin has to implement to define a new field. Fields
are used by the expression evaluator to extract information from an incoming
EventData
object.
- Since:
- WebLogic Process Integrator 2.0
- See Also:
FieldInfo
Method Summary |
java.lang.Object |
evaluate(EvaluationContext context)
Evaluate the field. |
void |
init(java.lang.String name,
java.lang.String eventDescriptor)
Set the name and event descriptor associated with this field. |
void |
setQualifier(PluginField qualifier)
Set the field qualifier. |
init
public void init(java.lang.String name,
java.lang.String eventDescriptor)
throws PluginException
- Set the name and event descriptor associated with this field.
This method provides plugin fields the opportunity to access external
data dictionary information to retrieve column details to be saved as
part of the compiled expression.
- Parameters:
name
- The field name.eventDescriptor
- The event descriptor.- Throws:
PluginException
- if the field is unable to initialize itself.
setQualifier
public void setQualifier(PluginField qualifier)
throws PluginException
- Set the field qualifier. This method is called when the expression
parser encounters a qualified field reference; it provides plugin fields
the opportunity to access external data dictionary information to
retrieve column details to be saved as part of the compiled expression.
- Parameters:
qualifier
- The field qualifier, of the same class as
this
object.- Throws:
PluginException
- if the qualifier is invalid, for example.
evaluate
public java.lang.Object evaluate(EvaluationContext context)
throws PluginException
- Evaluate the field. The expression evaluator calls this method when it
needs to retrieve the value of the field referenced by this object from
the event datum contained within the
context
parameter. The
plugin field must take account of any field
qualifiers
it has when calculating its value.
- Parameters:
context
- The evaluation context. The plugin field can call the
the EvaluationContext.getEventData()
to
access the event datum.- Returns:
- The result of evaluating this field against the event data
contained in the
context
parameter. - Throws:
PluginException
- if an exception occurs during field evaluation.
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All rights reserved.