Memory Adapter
The Memory adapter allows to store and retrieve values to respectively from the memory. You can find all data types and operations of the Memory adapter in the service panel at Base Types/Bridge Base/Base Components/Add Ons/Memory.
Using the Memory adapter, you can
Task | Adapter Operation | Description | Documentation Reference |
|---|---|---|---|
Store data to memory | store | You can use the Memory adapter to store data to memory. | |
Retrieve data from memory | retrieve | You can use the Memory adapter to retrieve data from memory. | |
Remove data from memory | remove | You can remove data elements from memory that have been stored to a dedicated key. | |
Clear the memory | clear | You can wipe the complete memory used by the service. |
Adding a Memory Adapter Operation to a Diagram
Expand the path to the Memory adapter in the service panel (Base Types/Bridge Base/Base Components/Add Ons/Memory):
You can drag out operations from the data model to any diagram:
The example shows how to add a Memory adapter operation to an BPMN execution diagram:
Configuring the Memory Adapter Operation
Once an operation has been added to a diagram, it needs to be configured as a Memory adapter. Select the newly added Memory adapter operation and switch to the Attributes panel. Depending on the diagram type you can see the following information (example BPMN execution diagram):
Attribute | Description | Allowed Values / Example |
|---|---|---|
Name | The name of the Memory adapter operation. | store |
Symbol Type | Operations added to a execution diagram are execution steps. | Execution Step |
All this is predefined and cannot be changed. Click Add Stereotype to define the selected operation as to be a Memory adapter:
Select Memory Adapter from the list of available adapter stereotypes. Click Save:
The Attributes panel shows the added adapter stereotype. Now you still need to configure the adapter. Expand the stereotype by clicking the arrow on the right:
To configure a Memory adapter, you have the following options:
scope: The scope the value should be stored to. The default scope is global. Configure this value if you want to store to session scope. Refer to section Memory Scope below for more information on the implications of the memory scope.
Refer to Memory Adapter Reference for further information. The adapter option action derives from the used operation. Do not configure this.
Use option Minus to remove unwanted configurations:
Memory Scope
By default, the memory is in scope of the service (server process), but it is also possible to store values in a request session context. Basically, the memory adapter is a thread-safe hash list allowing to
share objects between requests (service/global scope)
To store objects in global scope and to share them between requests to the same service, set scope to global on the Memory adapter. In this case, you need to propagate the memory key between requests, or use a static key.keep data for one request (session scope) only
To keep data for the request only, set scope to session on the Memory adapter. At the end of the request session, the memory will be cleared. Regarding the Designer, the session scope corresponds to the implementation of one execution diagram.
Refer to xUML Runtime Architecture and Transaction Concept for more information on what is regarded as a session by the Runtime in general, and about transaction handling.
MemoryAdapter_GuessingGame_Example
Click here to download a simple example model that shows the usage of the Memory adapter in Scheer PAS Designer.