Motivation for creating a new generation of OpenSCD:

1. Make is more easy to build your own distribution
2. Make is more easy to create custom plug-ins
3. Less tangled code
4. Reusable code
5. Faster development speed (once it is ready)
6. Plug-ins can be build in any code language and framework (as long as they adhere to the specifications)

OpenSCD-core plug-in

Practical example for CoMPAS. CoMPAS currently relies on fork of OpenSCD in order to add the needed functionality:

com-pas/compas-open-scd: A substation configuration description editor for projects using SCL IEC 61850-6 Edition 2 or greater (github.com)

The goal for CoMPAS would be to add the CoMPAS specific code as add-on to OpenSCD-next in form of plug-ins. The current "fork" will no longer be needed. CoMPAS will just make a distribution of OpenSCD including the CoMPAS plugins/extensions.

OpenSCD-core architecture overview

The OpenSCD next architecture consist of 5 major software components:

• OpenSCD-core
• Plug-ins
• Components
• add-ons

Overview of the global architecture

Components and their interaction. OpenSCD-core loads alle the "components/plugins etc".

A plugin can use EditEvent to make modifications in OpenSCD.

OpenSCD-Core

OpenSCD-core is main application of OpenSCD-next. OpenSCD-core will be loaded once people open the application. OpenSCD-core sets the requirements for the plug-ins.

OpenSCD Core consists of the open-scd  WebComponent, which is responsible for loading plugins and addons.

The open-scd  WebComponent is the outer shell of OpenSCD, containing limited functionality in order to make it flexible.

Editing of a (SCL) Document should be handled by OpenSCD Core. OpenSCD Core provides an API for Document editing by listening to CustomEvents. These CustomEvents can be dispatched b Plugins.

Based on a configuration file OpenSCD-core load the different Plug-ins/addins etc.

Functionalitiy of OpenSCD-core:

Loading addons/plug-ins

Display the selected plug-in

Handling SCL edits

Host the SCL doc editing

SCL doc editing

The SCL doc editing is reponsible for manipulating the SCL. It takes care of the right sequince/order of SCL edits. For more information see OpenSCD-core handling SCL Edits.

OpenSCD Plugins

OpenSCD plug-in is an addition to OpenSCD-core to add functionality. This could be generic 61850 functionality or vendor/utility specific functionalitiy. Examples: datatemplate editor, substationsection editor, GOOSE editing etc.

OpenSCD-core supports 2 types of plugins: menu plugins and editor plugins. These plugins have a different behavior. 

For more information see: OpenSCD-core plug-in

OpenSCD Components

OpenSCD Components are reusable WebComponents. Components can be used by plug-ins to build functionality faster, plug-in authors can also decide to build everything themselves.

Examples: filterdlistst are used in many plug-ins. In order to re-use the code, and filteredlist component is build.

OpenSCD add-ons

OpenSCD addons are an extension of OpenSCD-core to split functionality. This functionality can be pure technical and requires no custom UI. Example for some OpenSCD addons are Wizarding, Validating, Waiting, etc.

OpenSCD addons will be a replacement for current mixins, so there is no or less need to fork  OpenSCD-core and to build mixins on top of the fork. Addons allow experiments with (potential) new core functionality. Succesful addons can be merged into OpenSCD-core.

Example: Wizarding API is hard to make pefect in the first run. If started with an addon for wizarding, we can experiment/use. If it turns out that the addon is missing crucial functionality. We can introduce a new add-on next to the old addon (with its limitations).

What are mixins: TypeScript: Documentation - Mixins (typescriptlang.org)