1 files changed, 40 insertions, 0 deletions
diff --git a/src/data/composite/things/track/withPropertyFromAlbum.js b/src/data/composite/things/track/withPropertyFromAlbum.js
new file mode 100644
index 0000000..d41390f
--- /dev/null
+++ b/src/data/composite/things/track/withPropertyFromAlbum.js
@@ -0,0 +1,40 @@
+// Gets a single property from this track's album, providing it as the same
+// property name prefixed with '#album.' (by default).
+
+import {input, templateCompositeFrom} from '#composite';
+import {is} from '#validators';
+
+import {withPropertyFromObject} from '#composite/data';
+
+import withAlbum from './withAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withPropertyFromAlbum`,
+
+  inputs: {
+    property: input.staticValue({type: 'string'}),
+  },
+
+  outputs: ({
+    [input.staticValue('property')]: property,
+  }) => ['#album.' + property],
+
+  steps: () => [
+    withAlbum(),
+
+    withPropertyFromObject({
+      object: '#album',
+      property: input('property'),
+    }),
+
+    {
+      dependencies: ['#value', input.staticValue('property')],
+      compute: (continuation, {
+        ['#value']: value,
+        [input.staticValue('property')]: property,
+      }) => continuation({
+        ['#album.' + property]: value,
+      }),
+    },
+  ],
+});