parkerproject/index.html

## index.html
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>

  Input: <input type="text" ng-model="hello"><br>

  result: <span ng-bind="hello"></span>

  <script src="my-angular.js"></script>
  <script>
    angular
      .module('app', [])
      .controller('ctrl', function($scope){

        // Set hello to 'nihao'
        $scope.hello = 'nihao';
      });
  </script>
</body>
</html>

## my-angular.js
// Scope
function Scope() {

  // Watch
  this.$$watchers = [];

  this.$watch = function(watcherFn, listenerFn) {
    this.$$watchers.push({
      watcherFn: watcherFn,
      listenerFn: listenerFn
    });
  };

  // Digest
  this.$digest = function() {
    this.$$watchers.forEach(function(watcher) {
      var newValue = watcher.watcherFn();
      var oldValue = watcher.last;
      if (newValue !== oldValue) {
        watcher.listenerFn(newValue, oldValue);
        watcher.last = newValue;
      }
    });
  };

  // Apply
  this.$apply = function(exprFn) {
    try {
      if (exprFn) {
        exprFn();
      }
    } finally {
      this.$digest();
    }
  };

  this.$$directives = {
    'ng-bind': function($scope, element, attrs) {
      var prop = element.attributes['ng-bind'].value;
      $scope.$watch(function() {
        return $scope[prop];
      }, function(newValue, oldValue) {
        element.innerHTML = $scope[prop];
      });
    },
    'ng-model': function($scope, element, attrs) {
      var prop = element.attributes['ng-model'].value;
      $scope.$watch(function() {
        return $scope[prop];
      }, function(newValue, oldValue) {
        element.addEventListener("keyup", function(){
          $scope[prop] = element.value;
          $scope.$apply();
        });
      });
    }
  };

  // Compile
  this.$compile = function(element, $scope) {
    Array.prototype.forEach.call(
      element.children,
      function(child) {
        $scope.$compile(child, $scope);
      });
    Array.prototype.forEach.call(
      element.attributes,
      function(attribute) {
        var directive = $scope.$$directives[attribute.name];
        if (directive) {
          directive($scope, element, element.attributes);
        }
      });
  };

  this.$compile(document.body, this);

  this.$apply();
}

function Controller (){
  this.scope = new Scope();
}

function Angular(){
  this.module = function(name, requires){
    return this;
  };

  this.controllers = [];

  this.controller = function(name, ctrlFn){
    var ctrl = new Controller();
    ctrlFn(ctrl.scope);
    ctrl.scope.$apply();
    this.controllers.push(ctrl);
  };
}

window.angular = new Angular();
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<title>Document</title>
	</head>
	<body>

	Input: <input type="text" ng-model="hello"><br>

	result: <span ng-bind="hello"></span>

	<script src="my-angular.js"></script>
	<script>
	angular
	.module('app', [])
	.controller('ctrl', function($scope){

	// Set hello to 'nihao'
	$scope.hello = 'nihao';
	});
	</script>
	</body>
	</html>
	// Scope
	function Scope() {

	// Watch
	this.$$watchers = [];

	this.$watch = function(watcherFn, listenerFn) {
	this.$$watchers.push({
	watcherFn: watcherFn,
	listenerFn: listenerFn
	});
	};

	// Digest
	this.$digest = function() {
	this.$$watchers.forEach(function(watcher) {
	var newValue = watcher.watcherFn();
	var oldValue = watcher.last;
	if (newValue !== oldValue) {
	watcher.listenerFn(newValue, oldValue);
	watcher.last = newValue;
	}
	});
	};

	// Apply
	this.$apply = function(exprFn) {
	try {
	if (exprFn) {
	exprFn();
	}
	} finally {
	this.$digest();
	}
	};

	this.$$directives = {
	'ng-bind': function($scope, element, attrs) {
	var prop = element.attributes['ng-bind'].value;
	$scope.$watch(function() {
	return $scope[prop];
	}, function(newValue, oldValue) {
	element.innerHTML = $scope[prop];
	});
	},
	'ng-model': function($scope, element, attrs) {
	var prop = element.attributes['ng-model'].value;
	$scope.$watch(function() {
	return $scope[prop];
	}, function(newValue, oldValue) {
	element.addEventListener("keyup", function(){
	$scope[prop] = element.value;
	$scope.$apply();
	});
	});
	}
	};

	// Compile
	this.$compile = function(element, $scope) {
	Array.prototype.forEach.call(
	element.children,
	function(child) {
	$scope.$compile(child, $scope);
	});
	Array.prototype.forEach.call(
	element.attributes,
	function(attribute) {
	var directive = $scope.$$directives[attribute.name];
	if (directive) {
	directive($scope, element, element.attributes);
	}
	});
	};

	this.$compile(document.body, this);

	this.$apply();
	}

	function Controller (){
	this.scope = new Scope();
	}

	function Angular(){
	this.module = function(name, requires){
	return this;
	};

	this.controllers = [];

	this.controller = function(name, ctrlFn){
	var ctrl = new Controller();
	ctrlFn(ctrl.scope);
	ctrl.scope.$apply();
	this.controllers.push(ctrl);
	};
	}

	window.angular = new Angular();