Class EntityEventHandler

Abstract base class for an entity event handler.

Inheritance

object

MarshalByRefObject

EntityEventHandler

Implements

IEventHandler

Inherited Members

MarshalByRefObject.MemberwiseClone(bool)

MarshalByRefObject.GetLifetimeService()

MarshalByRefObject.CreateObjRef(Type)

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Namespace: Attachmate.Verastream.HostIntegrator.ScriptAPI

Assembly: Attachmate.Verastream.HostIntegrator.ScriptAPI.dll

Syntax

public abstract class EntityEventHandler : MarshalByRefObject, IEventHandler

Remarks

Abstract base class for an entity event handler. All classes that extend this class appear as entity event handlers in the VHI design tool.

Methods

EntityArrival(IEntityArrivalEvent)

Called when a new entity is recognized and validated as defined in the model.

Declaration

public virtual void EntityArrival(IEntityArrivalEvent vsEvent)

Parameters

Type	Name	Description
IEntityArrivalEvent	vsEvent	The event instance.

Remarks

Any exception thrown from this event will cause the currently running operation, if any, to fail.

Exceptions

Type	Condition
ApptrieveException	Any exception will interrupt the current client request or model activity.

EntityDeparture(IEntityDepartureEvent)

Called when the current entity is no longer recognized.

Declaration

public virtual void EntityDeparture(IEntityDepartureEvent vsEvent)

Parameters

Type	Name	Description
IEntityDepartureEvent	vsEvent	The event instance.

Remarks

If another entity is not recognized, this event can override the departure and stay at the previously recognized entity. When departure is overridden, this event will fire again the next time data is received from the host.

Any exception thrown from this event will cause the currently running operation, if any, to fail.

Exceptions

Type	Condition
ApptrieveException	Any exception will interrupt the current client request or model activity.

InitializeLifetimeService()

Tell the .NET Framework remoting system that instances of this type have an infinite lifetime.

Declaration

public override object InitializeLifetimeService()

Returns

Type	Description
object	A null value.

Overrides

MarshalByRefObject.InitializeLifetimeService()

MoveCursor(IEntityMoveCursorEvent)

Called when the cursor needs to move to a specific location on the terminal screen.

Declaration

public virtual void MoveCursor(IEntityMoveCursorEvent vsEvent)

Parameters

Type	Name	Description
IEntityMoveCursorEvent	vsEvent	The event instance.

Remarks

This event will fire in response to the following commands if the cursor is not already at the requested location:

• DefaultValue
• DefaultValueEncrypted
• MoveCursor
• ShiftCursor
• TransmitToAttr
• TransmitToAttrEncrypted
• TransmitToField
• TransmitToFieldEncrypted
• TransmitToOffset
• TransmitToOffsetEncrypted
• UpdateAttribute
• UpdateRecordSetField

If no method to move the cursor forward or backward is defined for a character mode model, this event will fire to position the cursor at each attribute and field before writing.

If the cursor is not positioned at the specified location upon returning from the event, VHI will fail the current client request.

Any exception thrown from this event will cause the current command to fail.

Exceptions

Type	Condition
ApptrieveException	Any exception will result in the move cursor to fail.

WriteAttributes(IWriteAttributesEvent)

Called when when a client or procedure requests to write one or more attributes on the entity.

Declaration

public virtual void WriteAttributes(IWriteAttributesEvent vsEvent)

Parameters

Type	Name	Description
IWriteAttributesEvent	vsEvent	The event instance.

Remarks

Called when when a client or procedure requests to write one or more attributes on the entity. In addition, the event is fired in response to the following commands:

• UpdateAttributes
• UpdateRecordSetFields

This event is not fired when an attribute or field is written with one of the following commands:

• DefaultValue
• DefaultValueEncrypted
• TransmitToAttr
• TransmitToAttrEncrypted
• TransmitToField
• TransmitToFieldEncrypted
• UpdateAttribute
• UpdateRecordSetField

The intended usage of this event is to orchestrate the order of attribute writes and the cursor movement between them. The actual writing of each attribute to the terminal can be done, but its recommended to use the IWriteAttributesEvent method WriteAttribute to write each attribute. This method ensures that the appropriate AttributeEventHandler method WriteAttribute, if any, is called.

Any exception thrown from this event will cause the write request to fail.

Exceptions

Type	Condition
ApptrieveException	Any exception will cause the writing of attributes to fail.

Implements

IEventHandler