Tips and Tricks for new async web client capabilities on model driven apps

Tips & Tricks for New Async Web Client
Capabilities on Model-Driven-Apps
MALAYSIA DYNAMICS 365 & POWER PLATFORM USER GROUP -
OCTOBER 2021 MEETUP

Mehdi El Amri
Business App Consultant @Umanis
Specialize in Microsoft Dynamics CE & Power Platform
Contributor @Community.Dynamics.com
Blogger
Futur Speaker 
https://community.dynamics.com/members/meelamri
https://xrmtricks.com/
@meelamri1
linkedin.com/in/meelamri/

Agenda
Intro:
 MDA Client Scripting
 Sync Events vs Async Events
 DEMO (1)
New Async Capabilities
Async OnSave Event
 App Configuration
 DEMO (2)
Async Custom Enable Rule
 How is work ?
 DEMO (DEMO 3)
Async OnLoad Event
 App Configuration
 DEMO (4)
Recap & resources

Intro - MDA Client Scripting
 Client Scripting using a RICH JavaScript client APIS.
 Execute JS CODE reacting to events:
 Form Loads
 Form Save
 Column Change
 Process Change …
 Never interact with the DOM directly. Always use
the Microsoft Client API
Supported Events: https://docs.microsoft.com/en-
us/powerapps/developer/model-driven-
apps/clientapi/reference/events

Intro - Sync Event
 When a task is executed synchronously, this means that we wait for one task to be completed
before moving on to another  One task depends on the completion of another.
Task 1 Task 2 Task 3
Start Finish
Sync Event: Tasks are executed synchronously

Intro - Async Events
 When a task is executed asynchronously, you can directly switch to another task before the
previous has been completed  One task does not depend on the other.
Task 1
(Start)
Task 2
(Start)
Start Finish
Task 1
(Finish)
Task 2
(Finish)
Async Event: Tasks can be executed asynchronously

Intro – Async Task in Sync Event (1)
 Sync events are supposed to execute synchronous tasks, but nothing prevents the
implementation of asynchronous tasks.
Task 1
Async Task 2
Start
Task 3
Start Finish
Async Task 2
Finish
Sync Event

Intro – Async Task in Sync Event (2)
 Scenario:
 When a column is changed, a function will be triggered that will execute an asynchronous code that
displays a dialog box. The resolution of the asynchronous code will be done in 5 seconds.
 DEMO (1)

New Async Capabilities (1)
Historically, the Client API implemented only synchronous events. Developers used
workarounds to synchronize their asynchronous code.
One example is to display a button based on the result of an asynchronous operation:
 To implement this, we use a Custom Enable Rule.
 This kind of code is executed synchronously.
 The Custom Enable Rule returns a value before the execution of the asynchronous operation is finished.
 The idea was to have a global variable to store the result of the asynchronous operation and to execute
the enable rule a second time. At the second execution, we retrieve the value from the global variable
instead of executing the asychronous operation for the second.
 Example: https://butenko.pro/2018/11/13/showing-ribbon-button-based-on-the-result-of-async-
operation/

New Async Capabilities (2)
Starting this year, the API client are beginning to support asynchronous events. These are the
following events:
 OnSave Event
 Custom Enable Rules
 OnLoad Event (not yet documented)
These capabilities will help developers to synchronize asynchronous code in an efficient way and
to use the power of the JavaScript to implement quite complex scenarios with less effort !
Please note that the OnLoad event is not yet officially supported. I do not recommend using the
asychronous capability for this event in Production at this time.

Async OnSave Event (1)
This event is triggered when a form is saved. This saving can be done manually by a user or
automatically by a JavaScript code.
The client API gives us the ability to implement an asynchronous logic when triggering this
event.
This new capability is not applied by default. Indeed, this behavior is strongly linked to the
application we use. In effect, the MDA must be configured to support this behavior.
This kind of behavior will allow us to easily implement validations using asynchronous
operations. For example, validating an email address or a phone number through a third party
API.
Docs suggests a method that requires manipulation of the app's XML definition to enable
asynchronous capability. I propose an easier and faster way to enable asynchronous capability
for your applications.

To enable asynchronous capability for the OnSave event in your app:
 Open the console and type the following script:

After the script execution, we can check that the Asynchronous behavior is applied for our app
by using the following query:
 /api/data/v9.2/appsettings?$filter=(contains(uniquename, '%AsyncOnSave%'))

Scenario:
 Validate the phone number of the contact before saving.
 Use Power Automate for validation:
 Validation in less than 10 seconds.
 What happens if the flow does not respond after 10 seconds.
DEMO (2):
 Display a dialog message confirming the save after Cloud Flow Validation.
 Cancel the save if the flow does not validate the phone number and display a message
 Display an error if the execution time exceeds 10 seconds.

Async Custom Enable Rule
Custom Enables Rules are rules implemented in JavaScript that decide on the display of the
ribbon buttons.
Custom Enables rules support returning a Promise rather than boolean for asynchronous rule.
Scenario:
 Display/Hide a button based on the result of async operation.
DEMO (3):
 We will use the same Cloud Flow as DEMO (2)
 Button is shown when the promise is resolved
 Button is hidden when the promise is rejected
 Code only … I didn’t add the button to my form  !!

Async OnLoad Event (1)
This event is triggered when a form is loading.
The client API gives us the ability to implement an asynchronous logic when triggering this
event.
This new capability is not applied by default. This behavior is strongly linked to the application
we use. In effect, the MDA must be configured to support this behavior.
This kind of behavior will allow us to easily implement some asynchronous logic before
displaying a form. For example, we can change the form based on an attribute value.
At the moment, this behavior is not yet documented, so it is not yet supported. We can enable
this behavior in the same way as the Save event.

To enable asynchronous capability for the OnLoad event in your app:
 Open the console and type the following script:

After the script execution, we can check that the Asynchronous behavior is applied for our app
by using the following query:
 /api/data/v9.2/appsettings?$filter=(contains(uniquename, '%AsyncOnLoad%'))

Scenario:
 Display the right form according to the result of an asynchronous operation
 We will mock the asynchronous action with the setTimeout() function
DEMO (4):
 What happen if the Load Event was Synchronous ?
 https://meelamri.files.wordpress.com/2021/05/synconload-event.gif?w=600
 What happen if the asynchronous operation is not resolved after 10 seconds ?

Recap & resources
Recap:
 Difference between Sync and Async Event
 Client API support 2 Async Events: OnLoad and OnSave
 OnChange Event is Sychronous !!
 Custom Enable Rules support Asynchronous operations
Resources:
 Docs:
 https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/reference
 https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/clientapi/reference/events/form-onsave
 https://docs.microsoft.com/en-us/dynamics365/customerengagement/on-premises/developer/customize-dev/define-ribbon-
enable-rules?view=op-9-1#custom-rule
 Demos source code:
 https://gist.github.com/melamriD365/a42ff66001285cbdd07d685a6daabbee

Tips and Tricks for new async web client capabilities on model driven apps

Tips and Tricks for new async web client capabilities on model driven apps

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