EDT Extensions

An EDT Extension (AxEdtExtension) modifies an existing Extended Data Type without altering its original source code. EDT extensions are the simplest extension type — they primarily allow property modifications and array element additions.

EDT extensions are created by right-clicking an EDT in the AOT and selecting Create extension. This creates an AxEdtExtension object named <OriginalEdtName>.<YourModelName> in your model.

What Can Be Extended

Capability	Description
Add Array Elements	Add new elements to array-type EDTs.
Modify Properties	Change property values on the EDT via PropertyModifications (e.g., StringSize, Label, HelpText).

note

EDT extensions are limited compared to table or form extensions. You cannot change the underlying base type, add relations, or modify the EDT's inheritance chain. For significant changes, consider creating a new EDT that extends the original.

Extension Naming Convention

Pattern	Example	Description
Extension object	CustAccount.SAMOModel	Base EDT name + dot + your model name.

Best Practices

• Be cautious with StringSize modifications. Increasing the string size of a widely-used EDT affects every field that references it, potentially requiring database column resizing across many tables.
• Label and HelpText overrides through EDT extensions affect all fields using that EDT globally — ensure the change is truly universal.
• Prefer creating derived EDTs over modifying base EDTs when the change should only apply to specific contexts.

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Properties

4/4 properties

Property	Display Name	Type	Description
EDT ExtensionAxEdtExtension
Name	Name	String	The name of the extension element (follows BaseEDT.Package naming).
IsObsolete	Is Obsolete	NoYes	Whether the extension is deprecated. Values: No (0), Yes (1).
Visibility	Visibility	CompilerVisibility	Access level visibility. Values: Private (0), Protected (1), Public (2), Internal (3), InternalProtected (4).
Tags	Tags	String	Tags for this element separated by semicolon.