2 files changed, 42 insertions, 0 deletions
diff --git a/src/data/composite/things/commentary-entry/index.js b/src/data/composite/things/commentary-entry/index.js
new file mode 100644
index 00000000..091bae1a
--- /dev/null
+++ b/src/data/composite/things/commentary-entry/index.js
@@ -0,0 +1 @@
+export {default as withWebArchiveDate} from './withWebArchiveDate.js';
diff --git a/src/data/composite/things/commentary-entry/withWebArchiveDate.js b/src/data/composite/things/commentary-entry/withWebArchiveDate.js
new file mode 100644
index 00000000..3aaa4f64
--- /dev/null
+++ b/src/data/composite/things/commentary-entry/withWebArchiveDate.js
@@ -0,0 +1,41 @@
+import {input, templateCompositeFrom} from '#composite';
+
+import {raiseOutputWithoutDependency} from '#composite/control-flow';
+
+export default templateCompositeFrom({
+  annotation: `withWebArchiveDate`,
+
+  outputs: ['#webArchiveDate'],
+
+  steps: () => [
+    {
+      dependencies: ['annotation'],
+
+      compute: (continuation, {annotation}) =>
+        continuation({
+          ['#dateText']:
+            annotation
+              ?.match(/https?:\/\/web.archive.org\/web\/([0-9]{8,8})[0-9]*\//)
+              ?.[1] ??
+            null,
+        }),
+    },
+
+    raiseOutputWithoutDependency({
+      dependency: '#dateText',
+      output: input.value({['#webArchiveDate']: null}),
+    }),
+
+    {
+      dependencies: ['#dateText'],
+      compute: (continuation, {['#dateText']: dateText}) =>
+        continuation({
+          ['#webArchiveDate']:
+            new Date(
+              dateText.slice(0, 4) + '/' +
+              dateText.slice(4, 6) + '/' +
+              dateText.slice(6, 8)),
+        }),
+    },
+  ],
+});