Customization in Dynamics 365 CRM

 

Code-Based Customization in Dynamics 365 CRM

1. When to Use Code Customization

Use it when:

• Business rules can’t be expressed via Business Rules, Flows, or OOB features.

• You need real-time server-side logic, complex data validation, or integration with external systems.

• You want to build custom UI components or automate client-side behavior.

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2. Types of Code-Based Customization

a. Plugins (Server-side C# logic)

• What: Event handlers that execute during record events (Create, Update, Delete, Assign, etc.)

• Where: Registered via Plugin Registration Tool or inside a solution.

• Use cases:

  • Validate field dependencies

  • Auto-generate values

  • Integrate with external APIs

• Execution pipelines:

  • Pre-validation, Pre-operation, Post-operation

• Run in: Synchronous or Asynchronous modes

b. Custom Workflows (Deprecated but still used)

• Custom logic triggered via workflow processes.

• Replaced mostly by Power Automate or plugins.

c. JavaScript (Client-side logic)

• What: Executes in the browser on forms and views.

• Use cases:

  • Field validation and conditional visibility

  • Auto-populate values

  • Form-level business logic

• Tools: Web Resources + Form Editor

d. Custom Connectors / APIs

• Use case: Integrate CRM with external systems via REST APIs.

• Options:

  • Webhooks

  • Azure Functions

  • Logic Apps or Middleware

e. PCF (PowerApps Component Framework)

• What: Build custom UI components for forms or dashboards.

• Tech: TypeScript + React (typically)

• Use case:

  • Data grids with advanced formatting

  • Map components, sliders, charts

• Works in Model-Driven Apps and Canvas Apps.

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3. Do's and Don'ts for Code Customization

DOs	DON'Ts
Use plugin isolation and sandbox model	Don’t use unmanaged code or reflection hacks
Keep plugin logic modular and reusable	Avoid large, complex plugins with 100s of lines
Use Dependency Injection (new SDK supports it)	Don’t hardcode connections or settings
Use JavaScript only when UX needs it	Don’t replicate server logic in JS
Write unit-testable business logic in shared libraries	Avoid direct calls to external APIs inside plugins
Log exceptions with TracingService	Don’t ignore error handling or retry logic
Follow naming conventions and version control	Don’t deploy code changes directly in production

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4. Tools Commonly Used

• Plugin Registration Tool (PRT)

• Visual Studio (for C# plugins, workflows)

• TypeScript + VS Code (for PCF)

• XrmToolBox for metadata work

• Fiddler/Postman for API testing

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5. Example Use Case

Scenario: On Opportunity close, send customer data to an external billing system.

Solution:

• Register a Post-Operation Plugin on Opportunity Close.

• Call external API using HttpClient.

• Log response and update Opportunity with billing status.