Create an AnnotationFactory and AnnotationPage models to support WebAnnotation in Mirador 3

__tests__/src/lib/AnnotationFactory.test.js

+import AnnotationFactory from '../../../src/lib/AnnotationFactory';
+import AnnotationList from '../../../src/lib/AnnotationList';
+import AnnotationPage from '../../../src/lib/AnnotationPage';
+
+describe('AnnotationFactory', () => {
+  describe('determineAnnotation', () => {
+    describe('when falsey', () => {
+      it('returns null', () => {
+        expect(AnnotationFactory.determineAnnotation(undefined)).toBeNull();
+      });
+    });
+    describe('when Presentation v3', () => {
+      it('returns an AnnotationPage', () => {
+        expect(AnnotationFactory.determineAnnotation({
+          type: 'AnnotationPage',
+        })).toBeInstanceOf(AnnotationPage);
+      });
+    });
+    describe('when Presentation v2', () => {
+      it('returns an AnnotationPage', () => {
+        expect(AnnotationFactory.determineAnnotation({
+          '@type': 'AnnotationList',
+        })).toBeInstanceOf(AnnotationList);
+      });
+    });
+  });
+});

__tests__/src/lib/AnnotationPage.test.js

+import AnnotationPage from '../../../src/lib/AnnotationPage';
+
+describe('AnnotationPage', () => {
+  describe('id', () => {
+    it('returns the id', () => {
+      expect(new AnnotationPage({ id: 'foo' }).id).toEqual('foo');
+    });
+  });
+  describe('present', () => {
+    it('checks for json', () => {
+      expect(new AnnotationPage().present()).toEqual(false);
+    });
+    it('checks for items', () => {
+      expect(new AnnotationPage({ id: 'foo' }).present()).toEqual(false);
+      expect(new AnnotationPage({ items: [] }).present()).toEqual(false);
+    });
+  });
+  describe('items', () => {
+    it('returns items', () => {
+      expect(new AnnotationPage(
+        { items: [{ foo: 'bar' }] },
+      ).items).toEqual([{ foo: 'bar' }]);
+    });
+  });
+  describe('resources', () => {
+    it('returns items', () => {
+      expect(new AnnotationPage(
+        { items: [{ foo: 'bar' }] },
+      ).resources).toEqual([{ foo: 'bar' }]);
+    });
+  });
+});

src/lib/AnnotationFactory.js

+import AnnotationList from './AnnotationList';
+import AnnotationPage from './AnnotationPage';
+
+/**
+ * Used to determine the type of Annotation supported by a version of the IIIF
+ * Presentation API.
+ */
+export default class AnnotationFactory {
+  /** */
+  static determineAnnotation(json, target) {
+    if (!json) {
+      return null;
+    }
+
+    // IIIF Presentation API v3. AnnotationPage
+    if (json.type === 'AnnotationPage') {
+      return new AnnotationPage(json, target);
+    }
+
+    // IIIF Presentation API v2. OpenAnnotation and SharedCanvas models
+    return new AnnotationList(json, target);
+  }
+}

src/lib/AnnotationPage.js

+/**
+ * Annotation representation for IIIF Presentation v3
+ * https://iiif.io/api/presentation/3.0/#55-annotation-page
+ */
+export default class AnnotationPage {
+  /** */
+  constructor(json, target) {
+    this.json = json;
+    this.target = target;
+  }
+
+  /** */
+  get id() {
+    return this.json.id;
+  }
+
+  /** */
+  present() {
+    return (this.items
+      && this.items.length > 0);
+  }
+
+  /** */
+  get items() {
+    if (!this.json || !this.json.items) return [];
+
+    return this.json.items;
+  }
+
+  /**
+   * Alias to items for compatibility for right now.
+   */
+  get resources() {
+    return this.items;
+  }
+}

src/state/selectors/annotations.js

 import { createSelector } from 'reselect';
 import filter from 'lodash/filter';
 import flatten from 'lodash/flatten';
-import AnnotationList from '../../lib/AnnotationList';
+import AnnotationFactory from '../../lib/AnnotationFactory';
 import { getCanvas, getVisibleCanvases } from './canvases';
 
 const getAnnotationsOnCanvas = createSelector(
@@ -22,7 +22,8 @@ const getPresentAnnotationsCanvas = createSelector(
     getAnnotationsOnCanvas,
   ],
   annotations => filter(
-    Object.values(annotations).map(annotation => annotation && new AnnotationList(annotation.json)),
+    Object.values(annotations)
+      .map(annotation => annotation && AnnotationFactory.determineAnnotation(annotation.json)),
     annotation => annotation && annotation.present(),
   ),
 );
@@ -48,7 +49,8 @@ const getPresentAnnotationsOnSelectedCanvases = createSelector(
     getAnnotationsOnSelectedCanvases,
   ],
   annotations => filter(
-    Object.values(annotations).map(annotation => annotation && new AnnotationList(annotation.json)),
+    Object.values(annotations)
+      .map(annotation => annotation && AnnotationFactory.determineAnnotation(annotation.json)),
     annotation => annotation && annotation.present(),
   ),
 );