1 files changed, 19 insertions, 0 deletions
diff --git a/src/data/composite/wiki-properties/flag.js b/src/data/composite/wiki-properties/flag.js
new file mode 100644
index 0000000..076e663
--- /dev/null
+++ b/src/data/composite/wiki-properties/flag.js
@@ -0,0 +1,19 @@
+// Straightforward flag descriptor for a variety of property purposes.
+// Provide a default value, true or false!
+
+import {isBoolean} from '#validators';
+
+// TODO: Not templateCompositeFrom.
+
+// TODO: The description is a lie. This defaults to false. Bad.
+
+export default function(defaultValue = false) {
+  if (typeof defaultValue !== 'boolean') {
+    throw new TypeError(`Always set explicit defaults for flags!`);
+  }
+
+  return {
+    flags: {update: true, expose: true},
+    update: {validate: isBoolean, default: defaultValue},
+  };
+}