Add prototype and class impelentation

tshemsedinov · tshemsedinov · commit 5c1013243655 · 2017-11-29T04:49:55.000+02:00
diff --git a/JavaScript/2-prototype.js b/JavaScript/2-prototype.js
@@ -0,0 +1,53 @@
+'use strict';
+
+const logable = fields => {
+
+  function Logable(data) {
+    this.values = data;
+  }
+
+  for (const key in fields) {
+    Object.defineProperty(Logable.prototype, key, {
+      get: function() {
+        console.log('Reading key:', key);
+        return this.values[key];
+      },
+      set: function(value) {
+        console.log('Writing key:', key, value);
+        const def = fields[key];
+        const valid = (
+          typeof(value) === def.type &&
+          def.validate(value)
+        );
+        if (valid) this.values[key] = value;
+        else console.log('Validation failed:', key, value);
+      }
+    });
+  }
+
+  Logable.prototype.toString = function() {
+    let result = this.constructor.name + ': ';
+    for (const key in fields) {
+      result += this.values[key] + ' ';
+    }
+    return result;
+  };
+
+  return Logable;
+
+};
+
+// Usage
+
+const Person = logable({
+  name: { type: 'string', validate: name => name.length > 0 },
+  born: { type: 'number', validate: born => !(born % 1) },
+});
+
+const p1 = new Person({ name: 'Marcus Aurelius', born: 121 });
+console.log(p1.toString());
+p1.born = 1923;
+console.log(p1.born);
+p1.born = 100.5;
+p1.name = 'Victor Glushkov';
+console.log(p1.toString());
diff --git a/JavaScript/3-class.js b/JavaScript/3-class.js
@@ -0,0 +1,47 @@
+'use strict';
+
+const logable = fields => class Logable {
+  constructor(data) {
+    this.values = data;
+    for (const key in fields) {
+      Object.defineProperty(Logable.prototype, key, {
+        get: function() {
+          console.log('Reading key:', key);
+          return this.values[key];
+        },
+        set: function(value) {
+          console.log('Writing key:', key, value);
+          const def = fields[key];
+          const valid = (
+            typeof(value) === def.type &&
+            def.validate(value)
+          );
+          if (valid) this.values[key] = value;
+          else console.log('Validation failed:', key, value);
+        }
+      });
+    }
+  }
+  toString() {
+    let result = this.constructor.name + '\t';
+    for (const key in fields) {
+      result += this.values[key] + '\t';
+    }
+    return result;
+  }
+};
+
+// Usage
+
+const Person = logable({
+  name: { type: 'string', validate: name => name.length > 0 },
+  born: { type: 'number', validate: born => !(born % 1) },
+});
+
+const p1 = new Person({ name: 'Marcus Aurelius', born: 121 });
+console.log(p1.toString());
+p1.born = 1923;
+console.log(p1.born);
+p1.born = 100.5;
+p1.name = 'Victor Glushkov';
+console.log(p1.toString());
