2019 Aug week4

2019/Aug/Week4/reactive-variables.js

@@ -3,6 +3,33 @@
  */
 module.exports = class ReactiveVariables {
   constructor(variables) {
-
+    const obj = {};
+    const variablesObj = {};
+    Object.keys(variables).forEach(key => {
+      if(typeof variables[key] === 'function') {
+        Object.defineProperty(obj, key, {
+          get: () => {
+            const value = variables[key].call(obj);
+            if(typeof variablesObj[key] === 'object') {
+              let shouldNew = false;
+              Object.keys(value).forEach(k => {
+                if(variablesObj[key][k] !== value[k]) {
+                  shouldNew = true;
+                }
+              });
+              if(shouldNew) {
+                variablesObj[key] = value;
+              }
+            }else {
+              variablesObj[key] = value;
+            }
+            return variablesObj[key];
+          }
+        });
+      }else {
+        obj[key] = variables[key];
+      }
+    });
+    return obj;
   }
 }