Enum in AL

What Is an Enum in AL?

An enum (enumeration) is an AL object that defines a named list of possible values. Each value represents a meaningful business state rather than a technical number or string.

An enum:

• Represents a controlled set of values
• Is strongly typed
• Can be reused across tables, pages, and codeunits
• Can be extended safely (if designed to allow it)

Enums are used where values are finite, known, and meaningful.

Why Enums Exist in Business Central

Earlier versions of Business Central used the Option data type, which had several problems:

• Values were position-based
• Extensions could not safely add new values
• Changes could break existing logic
• Code readability was poor

Enums exist to solve these issues by providing:

• Named values instead of numeric positions
• Upgrade-safe extensibility
• Clear intent in code
• Better long-term maintainability

Enums are now the preferred and recommended approach.

The following example defines an enum representing the status of customer feedback.

enum 50180 "Feedback Status"
{
    Extensible = true;

    value(0; Open)
    {
        Caption = 'Open';
    }

    value(1; Reviewed)
    {
        Caption = 'Reviewed';
    }

    value(2; Closed)
    {
        Caption = 'Closed';
    }
}
    

This enum:

• Defines a controlled set of states
• Uses readable names
• Is marked extensible for future expansion

//Enums are commonly used as field types in tables. 
field(10; Status; Enum "Feedback Status")
{
    DataClassification = CustomerContent;
}
    

This ensures:

• Only valid enum values can be stored • Data remains consistent • Code referencing the field is type-safe

Using an Enum in AL Code

Enums improve code readability and safety.

This is far clearer and safer than numeric or text-based comparisons.

When to Use Enums

Enums should be used when:

• Values are limited and predefined
• Each value has clear business meaning
• The value affects logic or behavior
• You want readable, self-documenting code

Typical examples include:

• Status fields
• Types or categories
• Processing states
• Workflow stages

What Is an Enum Extension?

An enum extension allows you to add new values to an existing enum without modifying the original enum object. This is critical for:

• Extending standard enums
• Adding customer-specific values
• Preserving upgrade safety

Enum extensions follow the same philosophy as table and page extensions.

The following example extends the previously defined enum.

enumextension 50181 "Feedback Status Extension" extends "Feedback Status"
{
    value(10; Escalated)
    {
        Caption = 'Escalated';
    }
}
    

This extension:

• Adds a new enum value
• Does not affect existing values
• Survives upgrades safely

Using Extended Enum Values in Code

Once extended, the new values behave like native enum values.

No special handling is required.

Extensible vs Non-Extensible Enums

Not all enums should be extensible. It is the property of this object which prevent Enum to be extensible or not.

• Extensible = true o Designed for customization
o Common in framework or standard enums
• Extensible = false
o Closed set of values
o Logic depends on complete control

Choosing extensibility is a design decision, not a technical default.

Enum vs Option (Important Concept)

Enums:

• Are named and typed
• Support extensions
• Are upgrade-safe
• Improve readability

Options:

• Are legacy
• Are position-based
• Should be avoided in new development

Enums should always be preferred.

Common Beginner Mistakes With Enums

Developers often:

• Use enums where free-text is required
• Forget to mark enums extensible
• Hardcode enum values instead of using names
• Change enum value IDs after release

Enum values should be treated as stable contracts.

Using Extended Enum Values in Code

Enums in AL provide a clean, readable, and upgrade-safe way to represent business states and controlled values. Enum Extensions allow these values to be expanded without breaking standard logic or upgrades.

A well-designed enum:

• Models business meaning clearly
• Uses stable value IDs
• Is extensible when appropriate
• Improves code clarity and safety

Understanding enums and enum extensions completes the business-state modeling layer of AL development.