data: track: withTrackArtDate

3 files changed, 87 insertions, 18 deletions

diff --git a/src/data/composite/things/track/index.js b/src/data/composite/things/track/index.js
index 4f913a5e..714858a0 100644
--- a/src/data/composite/things/track/index.js
+++ b/src/data/composite/things/track/index.js
@@ -13,3 +13,4 @@ export {default as withOriginalRelease} from './withOriginalRelease.js';
 export {default as withOtherReleases} from './withOtherReleases.js';
 export {default as withPropertyFromAlbum} from './withPropertyFromAlbum.js';
 export {default as withPropertyFromOriginalRelease} from './withPropertyFromOriginalRelease.js';
+export {default as withTrackArtDate} from './withTrackArtDate.js';
diff --git a/src/data/composite/things/track/withTrackArtDate.js b/src/data/composite/things/track/withTrackArtDate.js
new file mode 100644
index 00000000..e2c4d8bc
--- /dev/null
+++ b/src/data/composite/things/track/withTrackArtDate.js
@@ -0,0 +1,80 @@
+// Gets the date of cover art release. This represents only the track's own
+// unique cover artwork, if any.
+//
+// If the 'fallback' option is false (the default), this will only output
+// the track's own coverArtDate or its album's trackArtDate. If 'fallback'
+// is set, and neither of these is available, it'll output the track's own
+// date instead.
+
+import {input, templateCompositeFrom} from '#composite';
+import {isDate} from '#validators';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+import withDate from './withDate.js';
+import withHasUniqueCoverArt from './withHasUniqueCoverArt.js';
+import withPropertyFromAlbum from './withPropertyFromAlbum.js';
+
+export default templateCompositeFrom({
+  annotation: `withTrackArtDate`,
+
+  inputs: {
+    from: input({
+      validate: isDate,
+      defaultDependency: 'coverArtDate',
+      acceptsNull: true,
+    }),
+
+    fallback: input({
+      type: 'boolean',
+      defaultValue: false,
+    }),
+  },
+
+  outputs: ['#trackArtDate'],
+
+  steps: () => [
+    withHasUniqueCoverArt(),
+
+    raiseOutputWithoutDependency({
+      dependency: '#hasUniqueCoverArt',
+      mode: input.value('falsy'),
+      output: input.value({'#trackArtDate': null}),
+    }),
+
+    {
+      dependencies: [input('from')],
+      compute: (continuation, {
+        [input('from')]: from,
+      }) =>
+        (from
+          ? continuation.raiseOutput({'#trackArtDate': from})
+          : continuation()),
+    },
+
+    withPropertyFromAlbum({
+      property: input.value('trackArtDate'),
+    }),
+
+    {
+      dependencies: [
+        '#album.trackArtDate',
+        input('fallback'),
+      ],
+
+      compute: (continuation, {
+        ['#album.trackArtDate']: albumTrackArtDate,
+        [input('fallback')]: fallback,
+      }) =>
+        (albumTrackArtDate
+          ? continuation.raiseOutput({'#trackArtDate': albumTrackArtDate})
+       : fallback
+          ? continuation()
+          : continuation.raiseOutput({'#trackArtDate': null})),
+    },
+
+    withDate().outputs({
+      '#date': '#trackArtDate',
+    }),
+  ],
+});
diff --git a/src/data/things/track.js b/src/data/things/track.js
index d9254196..57d2ed20 100644
--- a/src/data/things/track.js
+++ b/src/data/things/track.js
@@ -67,6 +67,7 @@ import {
   withOriginalRelease,
   withOtherReleases,
   withPropertyFromAlbum,
+  withTrackArtDate,
 } from '#composite/things/track';
 
 export class Track extends Thing {
@@ -149,27 +150,14 @@ export class Track extends Thing {
       }),
     ],
 
-    // Date of cover art release. Like coverArtFileExtension, this represents
-    // only the track's own unique cover artwork, if any. This exposes only as
-    // the track's own coverArtDate or its album's trackArtDate, so if neither
-    // is specified, this value is null.
     coverArtDate: [
-      withHasUniqueCoverArt(),
-
-      exitWithoutDependency({
-        dependency: '#hasUniqueCoverArt',
-        mode: input.value('falsy'),
-      }),
-
-      exposeUpdateValueOrContinue({
-        validate: input.value(isDate),
-      }),
-
-      withPropertyFromAlbum({
-        property: input.value('trackArtDate'),
+      withTrackArtDate({
+        from: input.updateValue({
+          validate: isDate,
+        }),
       }),
 
-      exposeDependency({dependency: '#album.trackArtDate'}),
+      exposeDependency({dependency: '#trackArtDate'}),
     ],
 
     coverArtDimensions: [