Specify Transaction interface

- Separate proxy object and transaction API
- Define methods

Author: tshemsedinov

JavaScript/9-separate.js

@@ -0,0 +1,51 @@
+'use strict';
+
+// Interface definition
+
+function Transaction() {}
+
+Transaction.start = (data) => {
+  // place implementation here
+  return [obj, transaction];
+};
+
+// Transaction.delta
+Transaction.prototype.commit = () => {};
+Transaction.prototype.rollback = () => {};
+Transaction.prototype.revoke = () => {};
+Transaction.prototype.timeout = (msec) => {};
+Transaction.prototype.before = (event, listener) => {};
+Transaction.prototype.after = (event, listener) => {};
+// Events: commit, rollback, revoke, set, get, timeout
+
+// Usage
+
+const data = { name: 'Marcus Aurelius', born: 121 };
+
+const [obj, transaction] = Transaction.start(data);
+console.dir({ data });
+
+obj.name = 'Mao Zedong';
+obj.born = 1893;
+obj.city = 'Shaoshan';
+obj.age = (
+  new Date().getFullYear() -
+  new Date(transaction.born + '').getFullYear()
+);
+
+console.dir({ obj });
+console.dir({ delta: transaction.delta });
+
+transaction.commit();
+console.dir({ data });
+console.dir({ obj });
+console.dir({ delta: transaction.delta });
+
+obj.born = 1976;
+console.dir({ obj });
+console.dir({ delta: transaction.delta });
+
+transaction.rollback();
+console.dir({ data });
+console.dir({ obj });
+console.dir({ delta: transaction.delta });