Keep the structure of TTL files

Many Aspect Models are written or changed in a text editor (e.g. VS Code) and in the Aspect Model Editor. When the Aspect Model Editor saves a model, it writes the complete file again. This page describes which parts of the original file are kept and which are created again.

What is kept and what is created again

Part of the file Kept Notes

Part of the file	Kept	Notes
Comment block at the top of the file (e.g. copyright)	yes	Every file keeps its own header. The header from Settings > Header/Copyright is only used for models without a source file, e.g. new models.
Order of the elements (Aspect, Properties, Characteristics, …)	configurable	See Element order when saving. Renamed elements keep their position.
Declared prefixes	yes	Prefixes declared in the file are written even if no element uses them. See Prefixes.
Order of the attributes inside an element (`samm:preferredName`, `samm:properties`, …)	no	Always follows the SAMM specification (ESMF SDK formatter).
Indentation, line breaks and empty lines inside an element	no	Created by the ESMF SDK formatter.
Comments between or inside elements	no	Comments are not part of the RDF model and are lost on save. Only the comment block at the top of the file is kept.

Comment block at the top of the file (e.g. copyright)

yes

Every file keeps its own header. The header from Settings > Header/Copyright is only used for models without a source file, e.g. new models.

Order of the elements (Aspect, Properties, Characteristics, …)

configurable

See Element order when saving. Renamed elements keep their position.

Declared prefixes

yes

Prefixes declared in the file are written even if no element uses them. See Prefixes.

Order of the attributes inside an element (samm:preferredName, samm:properties, …)

Always follows the SAMM specification (ESMF SDK formatter).

Indentation, line breaks and empty lines inside an element

Created by the ESMF SDK formatter.

Comments between or inside elements

Comments are not part of the RDF model and are lost on save. Only the comment block at the top of the file is kept.

Use the text view to see what the file will look like before you save it.

Element order when saving

Open Settings > Editor and choose the Element order when saving:

Option	Behavior
Order of the ESMF SDK formatter (default)	The formatter defines the order. The order of the source file is not kept.
Keep order, insert new elements after their parent	Existing elements keep their position. A new element is written after the element which uses it, e.g. a new Characteristic after its Property.
Keep order, append new elements at the end	Existing elements keep their position. New elements are written at the end of the file.

Option

Behavior

Order of the ESMF SDK formatter (default)

The formatter defines the order. The order of the source file is not kept.

Keep order, insert new elements after their parent

Existing elements keep their position. A new element is written after the element which uses it, e.g. a new Characteristic after its Property.

Keep order, append new elements at the end

Existing elements keep their position. New elements are written at the end of the file.

Keeping the order of the file keeps Git diffs small: only the changed elements appear in the diff.

To bring a model into a new order once, use Sort elements alphabetically in the text view and save the model. The Aspect stays at the top. The new order is kept for later changes.

Example

Source file, written in a text editor:

# Copyright (c) 2026 Example Corp.

@prefix samm: <urn:samm:org.eclipse.esmf.samm:meta-model:2.2.0#> .
@prefix samm-c: <urn:samm:org.eclipse.esmf.samm:characteristic:2.2.0#> .
@prefix unit: <urn:samm:org.eclipse.esmf.samm:unit:2.2.0#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix : <urn:samm:com.example:1.0.0#> .

:Movement a samm:Aspect ;
   samm:properties ( :speed ) ;
   samm:operations ( ) .

# Speed in km/h
:speed a samm:Property ;
   samm:characteristic :Speed .

:Speed a samm:Measurement ;
   samm:dataType xsd:float ;
   samm-c:unit unit:kilometrePerHour .

With Keep order, insert new elements after their parent, a new Property :direction added in the graphical editor is saved like this:

The copyright header stays at the top.
:Movement, :speed and :Speed keep their order.
:direction is written directly after :Movement, which uses it, followed by its new Characteristic; then :speed and :Speed follow.
The comment # Speed in km/h is lost.

Limitations

If the formatted text cannot be split into single elements, the order of the formatter is used.