feat(dia.Element): add getPortGroupNames() (#2629)

examples/libavoid/src/avoid-router.js

@@ -186,8 +186,7 @@ export class AvoidRouter {
         // specific sides of the element.
 
         // Add pins to each port of the element.
-        const portGroups = Object.keys(element.prop('ports/groups'));
-        portGroups.forEach((group) => {
+        element.getPortGroupNames().forEach((group) => {
             const portsPositions = element.getPortsPositions(group);
             const { width, height } = element.size();
             const rect = new g.Rect(0, 0, width, height);

packages/joint-core/docs/src/joint/api/dia/Element/prototype/getPortGroupNames.html

@@ -0,0 +1,5 @@
+<pre class="docs-method-signature"><code>element.getPortGroupNames()</code></pre>
+
+Returns an array of port group names of the element.
+It returns all port group names defined on the element regardless of whether the port group has any ports or not.
+

packages/joint-core/src/dia/ports.mjs

@@ -280,6 +280,10 @@ export const elementPortPrototype = {
         }));
     },
 
+    getPortGroupNames: function() {
+        return Object.keys(this._portSettingsData.groups);
+    },
+
     /**
      * @param {string} groupName
      * @returns {Object<portId, {x: number, y: number, angle: number}>}

packages/joint-core/test/jointjs/elementPorts.js

@@ -2019,6 +2019,37 @@ QUnit.module('element ports', function() {
         });
     });
 
+    QUnit.module('getPortGroupNames', function() {
+
+        QUnit.test('return group names of all ports', function(assert) {
+
+                const shape = new joint.shapes.standard.Rectangle();
+
+                assert.deepEqual(shape.getPortGroupNames(), [], 'no groups');
+
+                shape.set({
+                    ports: {
+                        groups: {
+                            a: { position: 'left' },
+                            b: { position: 'right' }
+                        },
+                        items: [
+                            { id: 'one', group: 'a' },
+                            { id: 'two', group: 'b' },
+                            { id: 'three', group: 'b' },
+                            { id: 'four', group: 'b' }
+                        ]
+                    }
+                });
+
+                assert.deepEqual(shape.getPortGroupNames(), ['a', 'b'], 'group with ports');
+
+                shape.prop('ports/groups/c', { position: 'top' });
+
+                assert.deepEqual(shape.getPortGroupNames(), ['a', 'b', 'c'], 'group without ports');
+            });
+    });
+
     QUnit.module('portProp', function() {
 
         QUnit.test('set port properties', function(assert) {

packages/joint-core/types/joint.d.ts

@@ -559,6 +559,8 @@ export namespace dia {
 
         getPortIndex(port: string | Element.Port): number;
 
+        getPortGroupNames(): string[];
+
         portProp(portId: string, path: dia.Path): any;
 
         portProp(portId: string, path: dia.Path, value?: any, opt?: S): Element;