Process Extensions

Overview

Process Extensions are a mechanism for injecting custom logic in an existing process flow. It also gives the ability to execute multiple processes in a defined sequence.

Unlike Process Sets which allow the developer to override a complete Application Process, Process Extension Points must be defined before-hand in the place where they will take effect. They provide a much more controlled way of supporting custom behaviour when compared with Process Sets.

You may also have multiple implementations for a single Extension Point, whereas when using a Process Override only one implementation can be active at a time.

What You Will Learn

• How to Add an Extension Point to an Application Process
• How to Implement an Process Extension and register it to the Packages.xml

Adding an Extension Point

Create the following directory paths relative to the Process directory, Training/Pos/Sale

From the WorkspaceSetup\TrainingResources\ProcessExtensions directory, copy the Sale_1.0.xml Application Process into your newly created Sale folder

Right click the Sale_1.0.xml file select Enactor -> Register in Packages

Click Register

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By copying the Sale Process, a process override using the Process set mechanisms was used. More details can be in the Process Set Tutorial

Open the Sale Process

From the Outline view, expand the Actions group and search for the action SetAutoTimeout

Just beneath this action, are three Actions (collapsed)

• CheckHideQuantitySalePriviledge
• SetQuantitySale:WithPriviledgeHideQuantitySale
• SetQuantitySale:WithoutPriviledgeHideQuantitySale

Drag a box around them to select all three, and then move them down slightly to increase the space below the SetAutoTimeout action

From the Palette, expand the Actions Group, Add a new Call Extension Point Expand the Actions Groups

Place the Action bellow SetAutoTimeout Action

Move the link from Success outcome of SetAutoTimeout to the new Extension Point Action

From the Palette, click the Link tool and then add a link from the Fail outcome on the new action connecting it to the CheckHideQuantitySalePriviledge action.

Repeat this process to add links from the StopExtensionLinking and Success outcomes.

Right click the new Extension Point action and select Show Properties

Set the Action ID to CaptureCustomerExtension

Select to edit the Parameters property:

Add a new parameter by clicking on the :AddIcon: icon, or double-clicking on an empty line.

Set the parameter as follows:

Name field - select enactor.coreUI.ExtensionPointId from the drop down menu

Value field - Enter POSCaptureCustomerExtension

Click OK

Save the Process

Creating an Extension Point Process

Capture Customer Sale

Navigate to the directory path Training/Pos/Sale

Create a new Application Process with an ID of CaptureCustomerSale in the Sale folder, Right click the sale directory, select New -> Other

From the Select a wizard dialog, Expand the Enactor Development Group and select Application Process

Click Next >

Enter CaptureCustomerSale or the Process ID

Ensure Register in Packages is selected

Click Finish

Open the Packages.xml and select the Extensions tab

Within the Package Extensions / Extensions Section Click Add

Select the newly added extension, and then enter the following values:

• Name - TrainingCaptureCustomerSale
• Extension Point - POSCaptureCustomerExtension
• Extension URL - Click Browse and search for your newly created process CaptureCustomerSale
• Type - From the drop down menu select Process

Save the Packages.xml

Return to the CaptureCustomerSale Application Process

from the Palette, expand the States group, select and drag on a new State, placing it under the Process figure

Right click the State and select Show Properties

For the State ID enter Start

Edit the Events property, add a StateEntered event

Click OK

From the Palette add a new Message State, dropping it to the right of the Start state

Set the State ID to ShouldPromptForCustomer

Set the URL Property to /Message/PopUpModalYesNo

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you can select the value from the drop down menu

Set the Message Text Property to Capture Customer?

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A translatable message can be provided using the Message Base and Message Text Properties

Edit the Events property

Add the following Events

• OKPressed
• CancelPressed

Click OK

Add a link from the StateEntered event of the Start State connecting to the newly created state ShouldPromptForCustomer

From the Palette expand the Actions group, add an End Process Action

Edit the Properties for End Process Action:

Set the Action ID to End Process Success

Set the Process Outcome to Success by selecting the value from the drop down menu

Link both the events from the ShouldPromptForCustomer State to the End Process Success Action

Save the Process

Launch the Pos application after you sign in a dialog should now be presented with the message Capture Customer? and with two options:

Further Reading

The extensions section within the Packages.xml configuration file allows for the registration of various types of extensions against an extension point.

Currently the following package extensions are support are supported:

• PackageExtension

• WebPackageExtension

When implementing an extension point you can specify the following properties:

• Extension Id - A unique name for your extension

• Extension Point - The ID of the extension point that you want to implement

• Extension Type - The type of extension (Process, Page, Tab, JSP)

• Extension URL - The URL of the extension (Process Id, JSP)

• Extension Overrides (Optional) - Allows you to configure a set of existing extension point implementations that are replaced by this one (i.e. this allows you to disable other extension point implementations)

• Apply Before Packages - Allows you to signal that this extension point implementation must be called before the ones listed. This allows you to setup ordering of your extensions without disabling them

Extension Point Chaining

When there are multiple extension points implementing the same ID, Enactor will call them in sequence – if there is no order defined by the implementations (using either the Apply Before Packages, or Extension Overrides properties), then extensions may be run in any order.

If an Extension Point implementation wants to prevent chaining to further implementations, it can complete with the enactor.action.StopExtensionLinking or Fail outcomes. Any other outcome will be passed onto later implementations. Only the outcome from the last implementation will be returned to the calling process.

Answers

After completing the tutorial, this is how the application process and packages.xml should look like

The completed solution can be found in the ProcessExtensions Project located at /WorkspaceSetup/Solutions/ProcessExtensions

To run the solution, import the project as a maven project to your workspace

Select the Training Solution - Process Extensions Java launch