feat(drd): Add Decision Services for DMN 1.5 Support #983

Abiola-Farounbi · 2026-02-08T00:20:59Z

Proposed Changes

These changes implement the following requirements for the Decision Service element:

Ability to configure a decision service with input and output decision nodes encapsulated within its structure
A new model element was added to the palette, featuring two stacked rectangles that can be resized
Ability to draw decision services over nodes in a DMN
Ability to drag decision nodes into compartments of a decision service from the DMN
Resizability of the decision service box and divider
Addition of decision services as a new element tag in the XML

Checklist

Ensure you provide everything we need to review your contribution:

Contribution meets our definition of done
Pull request establishes context
Closes issue Addition of Decision Services for DMN 1.5 Support #957
Brief textual description of the changes
Screenshots or short videos showing UI/UX changes
Steps to try out, i.e. using the @bpmn-io/sr tool

Closes #957

CLAassistant · 2026-02-08T00:28:27Z

All committers have signed the CLA.

Copilot

Pull request overview

This PR introduces DMN 1.5 Decision Service support in the DRD modeler/viewer, adding the new element to creation tools, rendering, modeling behaviors, and XML/DI handling.

Changes:

Add Decision Service creation entry points (palette/context pad) plus label editing + variable name syncing support.
Introduce modeling behavior to manage DecisionService compartments (output/encapsulated) and auto-maintain input references.
Add rendering + DI factory support and extend test coverage with new fixtures/specs.

Reviewed changes

Copilot reviewed 23 out of 23 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
packages/dmn-js-shared/src/features/modeling/behavior/NameChangeBehavior.js	Sync DecisionService variable name on label/property name changes.
packages/dmn-js-drd/test/spec/features/palette/PaletteProviderSpec.js	Update palette entry count for new Decision Service tool.
packages/dmn-js-drd/test/spec/features/modeling/drd-updater-decision-service.dmn	New DMN test diagram covering DecisionService + move-in/out behavior.
packages/dmn-js-drd/test/spec/features/modeling/behavior/decision-service-behavior.dmn	New DMN test diagram for DecisionServiceBehavior scenarios.
packages/dmn-js-drd/test/spec/features/modeling/behavior/DecisionServiceBehaviorSpec.js	New unit tests for DecisionServiceBehavior (sectioning, refs, inputs).
packages/dmn-js-drd/test/spec/features/modeling/ElementFactorySpec.js	Add element factory tests for DecisionService defaults + variable creation.
packages/dmn-js-drd/test/spec/features/modeling/DrdUpdaterSpec.js	Extend DrdUpdater tests for move behavior involving DecisionServices.
packages/dmn-js-drd/test/spec/features/modeling/DrdFactorySpec.js	Add DI factory test for DMNDecisionServiceDividerLine creation.
packages/dmn-js-drd/test/spec/draw/DrdRendererSpec.js	Add smoke test for rendering a DecisionService fixture.
packages/dmn-js-drd/test/fixtures/dmn/decision-service.dmn	New rendering fixture containing a DecisionService + divider line.
packages/dmn-js-drd/src/features/rules/DrdRules.js	Allow DecisionService create/move/resize and define connection rules.
packages/dmn-js-drd/src/features/palette/PaletteProvider.js	Add palette entry to create Decision Service.
packages/dmn-js-drd/src/features/modeling/behavior/index.js	Register DecisionServiceBehavior in modeling behaviors module.
packages/dmn-js-drd/src/features/modeling/behavior/DecisionServiceBehavior.js	Implement DecisionService compartment logic + input ref auto-update.
packages/dmn-js-drd/src/features/modeling/behavior/CreateConnectionBehavior.js	Extend connection ref creation logic for DecisionService-related connections.
packages/dmn-js-drd/src/features/modeling/ElementFactory.js	Add DecisionService default sizing, DI divider line, and variable initialization.
packages/dmn-js-drd/src/features/modeling/DrdUpdater.js	Update decision services on moves/deletes and on requirement changes.
packages/dmn-js-drd/src/features/modeling/DrdFactory.js	Add helper to create DMNDecisionServiceDividerLine DI elements.
packages/dmn-js-drd/src/features/label-editing/LabelUtil.js	Enable label editing for DecisionService (name attribute).
packages/dmn-js-drd/src/features/label-editing/LabelEditingProvider.js	Adjust label editing positioning behavior for DecisionService.
packages/dmn-js-drd/src/features/context-pad/ContextPadProvider.js	Enable context pad append actions for DecisionService.
packages/dmn-js-drd/src/draw/DrdRenderer.js	Add visual rendering of DecisionService (box, divider, section labels).
packages/dmn-js-drd/assets/css/dmn-js-drd.css	Add palette icon styling for Decision Service entry.

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packages/dmn-js-drd/test/spec/features/modeling/drd-updater-decision-service.dmn

Copilot · 2026-02-10T09:19:32Z

packages/dmn-js-drd/src/draw/DrdRenderer.js

+     'dmn:DecisionService': function(p, element) {
+      var rect = drawRect(p, element.width, element.height, 12, {
+        stroke: getStrokeColor(element, defaultStrokeColor),
+        strokeWidth: 4,
+        fill: getFillColor(element, defaultFillColor)
+      });
+
+      var dividerY = element.height / 2;
+      var line = svgCreate('line');
+      svgAttr(line, {
+        x1: 0,
+        y1: dividerY,
+        x2: element.width,
+        y2: dividerY,
+        stroke: getStrokeColor(element, defaultStrokeColor),
+        strokeWidth: 2


The divider line is rendered at element.height / 2, ignoring the imported/stored DI divider line (DMNDecisionServiceDividerLine). This will render DecisionServices incorrectly when the divider is not centered (e.g. after divider resize or when importing DI). Compute the divider position from element.businessObject.di.decisionServiceDividerLine.waypoint (convert absolute -> local coordinates), with a center fallback when DI is missing.

This is correct, we should take the XML values into account.

Copilot · 2026-02-10T09:19:32Z

packages/dmn-js-drd/src/features/modeling/behavior/DecisionServiceBehavior.js

+DecisionServiceBehavior.prototype._getDividerPosition = function(decisionServiceElement) {
+  return decisionServiceElement.y + (decisionServiceElement.height / 2);
+};


_getDividerPosition always assumes the divider is centered (height / 2). If the divider line can be moved/resized or if DI imports a non-centered divider, section classification (output vs encapsulated) will be wrong. Derive the divider Y from the DecisionService DI (decisionServiceBo.di.decisionServiceDividerLine.waypoint) and fall back to center only when it is not available.

Copilot · 2026-02-10T09:19:32Z

packages/dmn-js-drd/src/features/modeling/ElementFactory.js

+      if (is(businessObject, 'dmn:DecisionService')) {
+        size = this._getDefaultSize(businessObject);
+        var dividerY = (attrs.y || 0) + (size.height / 2);
+        var dividerWaypoints = [
+          { x: attrs.x || 0, y: dividerY },
+          { x: (attrs.x || 0) + size.width, y: dividerY }
+        ];
+        businessObject.di.decisionServiceDividerLine = drdFactory.createDiDividerLine(dividerWaypoints);
+


ElementFactory creates and stores decisionServiceDividerLine waypoints once at creation time, but there is no code updating these waypoints when the DecisionService is moved/resized (or when the divider is moved). This will cause exported DMN DI to become stale. Consider updating the divider line waypoints in DrdUpdater.updateBounds / relevant resize handlers whenever the DecisionService bounds (or divider position) changes.

Copilot · 2026-02-10T09:19:32Z

packages/dmn-js-drd/test/fixtures/dmn/decision-service.dmn

+          <di:waypoint x="0" y="75" />
+          <di:waypoint x="200" y="75" />


The DMNDecisionServiceDividerLine waypoints here (x=0..200, y=75) don't line up with the shape bounds (x=330, y=225, width=400, height=335). If divider line waypoints are in diagram coordinates (like other DMNDI waypoints), this fixture will import with an incorrect divider position. Align the divider waypoints with the shape bounds (or clarify/update if divider waypoints are meant to be local coordinates).

Suggested change

<di:waypoint x="0" y="75" />

<di:waypoint x="200" y="75" />

<di:waypoint x="330" y="300" />

<di:waypoint x="530" y="300" />

Copilot · 2026-02-10T09:19:33Z

packages/dmn-js-drd/src/features/rules/DrdRules.js

+    if (is(target, 'dmn:DecisionService')) {
+      return { type: 'dmn:KnowledgeRequirement' };
+    }
+


canConnect allows Decision -> DecisionService and returns a dmn:KnowledgeRequirement (lines 100-112). However CreateConnectionBehavior determines the required* ref based on the source element type, so this path will create a KnowledgeRequirement with requiredDecision instead of requiredKnowledge. DrdImporter._getSource only looks at requiredKnowledge for KnowledgeRequirements, so the connection will not import/roundtrip correctly. Either disallow this connection type or ensure KnowledgeRequirement refs are always written to requiredKnowledge regardless of source element type.

Suggested change

if (is(target, 'dmn:DecisionService')) {

return { type: 'dmn:KnowledgeRequirement' };

}

packages/dmn-js-drd/src/features/modeling/behavior/CreateConnectionBehavior.js

Co-authored-by: Copilot <[email protected]>

barmac · 2026-02-10T14:30:16Z

Thank you for your pull request! Before we merge it, let's make sure that it meets the definition of done.

It looks that the interaction is not quite there yet. We should render the decision service below other elements so that they don't get hidden. I'd also envision that the encapsulated & output decisions should move together with the decision service element. Let me know if anything is unclear.

Screen.Recording.2026-02-10.at.15.28.51.mov

Screen.Recording.2026-02-10.at.15.29.18.mov

Abiola-Farounbi · 2026-02-13T00:03:03Z

Thank you for the feedback @barmac

For the first point, I have addressed the rendering issue by setting the DecisionService Element fill to transparent, which prevents contained decisions from being hidden. This works as expected and maintains visibility of all elements.
For the second point, I tested the interaction and found that the current implementation works as expected when a Decision element is dragged onto the DecisionService (rather than moving the DecisionService over existing Decisions). This was the initial assumption for the feature, as demonstrated in the demo below.

If the accurate interaction is for contained Decisions to move together with the DecisionService when the DecisionService is placed on it, could you recommend the best approach to implement this?

Abiola-Farounbi and others added 2 commits February 7, 2026 21:49

Add decision service feature to master-copy

c19c8cf

remove unwanted changes

a1ca559

Abiola-Farounbi marked this pull request as draft February 8, 2026 00:26

Abiola-Farounbi marked this pull request as ready for review February 8, 2026 00:31

Abiola-Farounbi changed the title ~~feat(drd): Add Decision Services for DMN 1.5 Support #957~~ feat(drd): Add Decision Services for DMN 1.5 Support Feb 8, 2026

barmac requested a review from Copilot February 10, 2026 09:14

Copilot started reviewing on behalf of barmac February 10, 2026 09:14 View session

Copilot AI reviewed Feb 10, 2026

View reviewed changes

barmac and others added 2 commits February 10, 2026 15:15

test: fix xml

146e8f5

Co-authored-by: Copilot <[email protected]>

chore: fix typo

784cce2

Co-authored-by: Copilot <[email protected]>

barmac added needs review Review pending in progress Currently worked on and removed needs review Review pending labels Feb 10, 2026

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feat(drd): Add Decision Services for DMN 1.5 Support #983

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	if (is(target, 'dmn:DecisionService')) {
	return { type: 'dmn:KnowledgeRequirement' };
	}

feat(drd): Add Decision Services for DMN 1.5 Support #983

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