Introduction to the development process
You can extend Business Central with add-on apps, vertical or horizontal solutions, and integration with other products and services.
To customize Business Central, you would typically develop one or more extension(s), also referred to as apps. Extensions is a programming model where functionality is defined as an addition to existing objects and it defines how these objects are different or modify the behavior of the solution.
All functionality in Business Central is coded in objects. The extension model is object-based; you create new objects and extend existing objects depending on what you want your extension to do.
These objects are stored as code, known as application language (AL) code, and are saved in files with an .al file extension.
AL is the programming language that is used for manipulating data (such as retrieving, inserting, and modifying records) in a Business Central database and controlling the implementation of the various application objects, such as pages, reports, or codeunits.
With AL, you can create business rules to ensure that the data that is stored in the database is meaningful and consistent with the way that customers do business.
You can choose from several options for creating new objects with the AL Language extension for Visual Studio Code.
Visual Studio Code and the AL Language extension let you complete the following tasks:
Create new files for your solution.
Get assistance with creating the appropriate configuration and setting files.
Use code snippets that provide templates for coding application objects.
Get compiler validation while coding.
Publish your changes and see the code running.
Extensions are compiled as .app package files. The .app package file can be deployed to the Business Central server. An .app package contains the various artifacts that deliver the new functionality to the Business Central deployment. It is also a manifest that specifies the name, publisher, version, and other attributes of the extension.
When all development and testing is done, you can submit your extension package to Microsoft AppSource.
AppSource is Microsoft's marketplace for your Business Central offerings. Going to market with AppSource is a great idea for several reasons. For example, it allows you to promote your brand, expand your reach, accelerate the customer journey, and upsell your solutions. AppSource connects you with millions of Microsoft 365 and Dynamics 365 business users. The process and validation requirements to submit an extension to AppSource isn't covered in this learning path. Some links to resources about app validation are available from the Ready to Go Program.
The extension that you will create is called a per tenant extension, or a PTE. A PTE is an extension that is created in a certain object range that can be published manually to a certain Business Central tenant.