1 files changed, 47 insertions, 0 deletions
diff --git a/src/data/things/additional-file.js b/src/data/things/additional-file.js
new file mode 100644
index 00000000..398d0af5
--- /dev/null
+++ b/src/data/things/additional-file.js
@@ -0,0 +1,47 @@
+import {input} from '#composite';
+import Thing from '#thing';
+import {isString, validateArrayItems} from '#validators';
+
+import {contentString, simpleString, thing} from '#composite/wiki-properties';
+
+import {exposeConstant, exposeUpdateValueOrContinue}
+  from '#composite/control-flow';
+
+export class AdditionalFile extends Thing {
+  static [Thing.getPropertyDescriptors] = () => ({
+    // Update & expose
+
+    thing: thing(),
+
+    title: simpleString(),
+
+    description: contentString(),
+
+    filenames: [
+      exposeUpdateValueOrContinue({
+        validate: input.value(validateArrayItems(isString)),
+      }),
+
+      exposeConstant({
+        value: input.value([]),
+      }),
+    ],
+  });
+
+  static [Thing.yamlDocumentSpec] = {
+    fields: {
+      'Title': {property: 'title'},
+      'Description': {property: 'description'},
+      'Files': {property: 'filenames'},
+    },
+  };
+
+  get paths() {
+    if (!this.thing) return null;
+    if (!this.thing.getOwnAdditionalFilePath) return null;
+
+    return (
+      this.filenames.map(filename =>
+        this.thing.getOwnAdditionalFilePath(this, filename)));
+  }
+}