Querying 365 data using the Web API endpoint
As the Dynamics platforms evolved over the years, new features were introduced to keep the platforms modern and up to date. In older versions, the only way to communicate with Dynamics CRM programmatically was through SOAP web services. In later years, the Microsoft Dynamics product team introduced OData endpoints that greatly simplified and modernized the communication mechanism.
In this recipe, we will retrieve the list of activities associated with a contact, and then display a warning message if any of the activities are open and assigned to the current logged-in user.
Getting ready
To perform the customization, you will require access to a Dynamics 365 module along with a System Customizer
 or higher role. An IDE or a JavaScript editor of your choice is also recommended. To test your OData queries, consider using the CRM REST Builder solution written by Microsoft MVP, Jason Lattimer. Also, consider a REST query tool to rapidly test your queries...