3 files changed, 47 insertions, 42 deletions
diff --git a/src/data/composite/things/artwork/index.js b/src/data/composite/things/artwork/index.js
index b92bff72..2cd3c388 100644
--- a/src/data/composite/things/artwork/index.js
+++ b/src/data/composite/things/artwork/index.js
@@ -1 +1 @@
-export {default as withDate} from './withDate.js';
+export {default as withContainingArtworkList} from './withContainingArtworkList.js';
diff --git a/src/data/composite/things/artwork/withContainingArtworkList.js b/src/data/composite/things/artwork/withContainingArtworkList.js
new file mode 100644
index 00000000..9c928ffd
--- /dev/null
+++ b/src/data/composite/things/artwork/withContainingArtworkList.js
@@ -0,0 +1,46 @@
+// Gets the list of artworks which contains this one, which is functionally
+// equivalent to `this.thing[this.thingProperty]`. If the exposed value is not
+// a list at all (i.e. the property holds a single artwork), this composition
+// outputs null.
+
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+import {withPropertyFromObject} from '#composite/data';
+
+export default templateCompositeFrom({
+  annotation: `withContainingArtworkList`,
+
+  outputs: ['#containingArtworkList'],
+
+  steps: () => [
+    raiseOutputWithoutDependency({
+      dependency: 'thing',
+      output: input.value({'#containingArtworkList': null}),
+    }),
+
+    raiseOutputWithoutDependency({
+      dependency: 'thingProperty',
+      output: input.value({'#containingArtworkList': null}),
+    }),
+
+    withPropertyFromObject({
+      object: 'thing',
+      property: 'thingProperty',
+    }).outputs({
+      '#value': '#containingValue',
+    }),
+
+    {
+      dependencies: ['#containingValue'],
+      compute: (continuation, {
+        ['#containingValue']: containingValue,
+      }) => continuation({
+        ['#containingArtworkList']:
+          (Array.isArray(containingValue)
+            ? containingValue
+            : null),
+      }),
+    },
+  ],
+});
diff --git a/src/data/composite/things/artwork/withDate.js b/src/data/composite/things/artwork/withDate.js
deleted file mode 100644
index 5e05b814..00000000
--- a/src/data/composite/things/artwork/withDate.js
+++ /dev/null
@@ -1,41 +0,0 @@
-import {input, templateCompositeFrom} from '#composite';
-
-import {raiseOutputWithoutDependency} from '#composite/control-flow';
-import {withPropertyFromObject} from '#composite/data';
-
-export default templateCompositeFrom({
-  annotation: `withDate`,
-
-  inputs: {
-    from: input({
-      defaultDependency: 'date',
-      acceptsNull: true,
-    }),
-  },
-
-  outputs: ['#date'],
-
-  steps: () => [
-    {
-      dependencies: [input('from')],
-      compute: (continuation, {
-        [input('from')]: date,
-      }) =>
-        (date
-          ? continuation.raiseOutput({'#date': date})
-          : continuation()),
-    },
-
-    raiseOutputWithoutDependency({
-      dependency: 'dateFromThingProperty',
-      output: input.value({'#date': null}),
-    }),
-
-    withPropertyFromObject({
-      object: 'thing',
-      property: 'dateFromThingProperty',
-    }).outputs({
-      ['#value']: '#date',
-    }),
-  ],
-})