Microsoft Dynamics NAV supports different types of events for different purposes. This topic describes the different types.
Business Events
A
business event is a custom event. It defines a formal contract that carries an
implicit promise not to change in future releases. It is the expectation that
business events are published by solution ISVs, including Microsoft.
Business events can be compared with
publicly released APIs on which 3rd party solution provider develop
integrations and additions. Therefore, the downstream cost of making changes to
a business event implementation can be considerable for those who use the event
in their applications. There may be some cases where changes are required;
however, you should keep these to an absolute minimum.
Development considerations
A typical business event reflects
changes in “state” with regards to a process. This makes them very well suited
for workflow. An example of a business event could be when a sales order has
been posted. It is important to note that business events should not be tied to
the implementation-details, such as the tables or fields in which the data is
stored. Preferably, the event publisher developer should be free to change the
implementation, while still keeping the business event intact.
Documentation
Business events must be documented
with the solution, including the before-state and after-state of the events.
Integration Events
An
integration event is also a custom event, like a business event, except that it
does not carry the same promise of not changing, nor does it have the
restriction not to expose implementation details.
The main purpose of integration
events is to enable the integration of other solutions with Microsoft Dynamics
NAV without having to perform traditional code modifications.
Development considerations
An integration event can be changed
to a business event later. At which time, it must adhere to the same implied
contract and commitment as any business event. It can also simply be
designed-in hook points for external add-ons.
Documentation
There are no formal requirements for
integration events because they follow local partner best practices.
Trigger Events
Unlike
business and integration events which must be programmed, trigger events are
predefined events. Trigger events are raised by the system when it performs
database table operations, such as deleting, inserting, modifying, and renaming
a record. Trigger events are closely associated with the table triggers for
database operations: OnDelete, OnInsert, OnModify, OnRename, and OnValidate
(for fields).
Available
Trigger Events
For
each database operation, there is a "before" and "after"
trigger event with a fixed signature. The following table describes the
available trigger events:
Trigger event with signature
|
Description
|
OnBeforeDeleteEvent(VAR Rec: Record,
RunTrigger: Boolean) |
Executed before a record is deleted from a
table. |
OnAfterDeleteEvent(VAR Rec: Record,
RunTrigger: Boolean) |
Executed after a record is deleted from a
table. |
OnBeforeInsertEvent(VAR Rec: Record,
RunTrigger: Boolean) |
Executed before a record is inserted in a
table. |
OnAfterInsertEvent(VAR Rec: Record,
RunTrigger: Boolean) |
Executed after a record is inserted in a
table. |
OnBeforeModifyEvent(VAR Rec: Record,
VAR xRec: Record, RunTrigger: Boolean) |
Executed before a record is modified in a
table. |
OnAfterModifyEvent(VAR Rec: Record,
VAR xRec: Record, RunTrigger: Boolean) |
Executed after a record is modified in a
table. |
OnBeforeRenameEvent(VAR Rec: Record,
VAR xRec: Record, RunTrigger: Boolean) |
Executed before a record is renamed in a
table. |
OnAfterRenameEvent(VAR Rec: Record,
VAR xRec: Record, RunTrigger: Boolean) |
Executed after a record is renamed in a
table. |
OnBeforeValidateEvent(VAR Rec:
Record, VAR xRec: Record, RunTrigger: Boolean; CurrentFieldNo: Integer) |
Executed before a field is validated when
its value has been changed. |
OnAfterValidateEvent(VAR Rec: Record,
VAR xRec: Record, RunTrigger: Boolean; CurrentFieldNo: Integer) |
Executed after a field is validated when
its value has been changed. |
The following table describes the
parameters of the trigger events:
Parameter
|
Type
|
Description
|
| Rec |
Record |
The table that raises the event. |
| xRec |
Record |
The table that raises the event. |
| RunTrigger |
Boolean |
Specifies whether to execute the code in
the event trigger when it i invoked. If this parameter is true, the code will
be executed. If this parameter is false, then the code is not executed. |
| CurrentFieldNo |
Integer |
The number of the field that raises the
event. |
Development
Considerations
Trigger
events are published by the runtime and cannot be raised programmatically.
The relative order of execution of
trigger events, table triggers, and database operations is as follows:
Order
|
Item
|
Example
|
| 1 |
Trigger event (before) |
OnBeforeDeleteEvent |
| 2 |
Table trigger |
OnDelete |
| 3 |
Global table trigger in codeunit 1 |
OnDatabaseDelete |
| 4 |
Database operations |
Delete the record |
| 5 |
Trigger event (after) |
OnAfterDeleteEvent |
Trigger events do not appear in C/AL
Editor from the Table Designer in the Microsoft Dynamics NAV Development
Environment.
Subscriber functions cannot access
the sender and or access global variables.
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