bennadel/data_vs_behavior.htm

## data_vs_behavior.htm
<!doctype html>
<html>
<head>
	<title>Domain Models Expose Behavior, Not State</title>

	<script type="text/javascript">


		// I model a Task that can be completed.
		function Task( id, description, isComplete, dateCreated, dateCompleted ){

			// Store internal, private properties.
			this._id = id;
			this._description = description;
			this._isComplete = isComplete;
			this._dateCreated = dateCreated;
			this._dateCompleted = dateCompleted;

		}

		// Define class propertiers.
		Task.prototype = {

			// I set the new description.
			changeDescription: function( description ){

				this._description = description;

			},


			// I complete the task.
			complete: function(){

				// Make sure the task isn't already complete.
				if (this.isComplete()){

					throw( new Error( "TaskAlreadyComplete" ) );

				}

				// Flag as complete.
				this._isComplete = true;
				this._dateCompleted = new Date();

			},


			// I determine if the task is completed.
			isComplete: function(){

				return( this._isComplete );

			},


			// I determine if the task is open.
			isOpen: function(){

				return( !this.isComplete() );

			},


			// I re-open a completed task.
			open: function(){

				// Make sure the task isn't already open.
				if (this.isOpen()){

					throw( new Error( "TaskAlreadyOpen" ) );

				}

				// Flag as open.
				this._isComplete = false;
				this._dateCompleted = null;

			},


			// -- Acccessors for output and persistence. -- //


			getDateCompleted: function(){
				// ..
			},


			getDateCreated: function(){
				// ..
			},


			getDescription: function(){
				// ...
			},


			getID: function(){
				// ...
			},


			getIsComplete: function(){
				// ...
			}

		};


		// -------------------------------------------------- //
		// -------------------------------------------------- //


		// Create our existing task.
		var task = new Task( 1, "Buy flowers", false, "2012/07/02", null );

		// Mess with task.
		console.log( "Task open?", task.isOpen() );
		task.complete();
		console.log( "Task open?", task.isOpen() );
		console.log( "Task complete?", task.isComplete() );

		// Try to close the task twice in a row.
		try {
			task.complete();
		} catch (error){
			console.log( "Error:", error.message );
		}


	</script>
</head>
<body>
	<!-- Left intentionally blank. -->
</body>
</html>
	<!doctype html>
	<html>
	<head>
	<title>Domain Models Expose Behavior, Not State</title>

	<script type="text/javascript">


	// I model a Task that can be completed.
	function Task( id, description, isComplete, dateCreated, dateCompleted ){

	// Store internal, private properties.
	this._id = id;
	this._description = description;
	this._isComplete = isComplete;
	this._dateCreated = dateCreated;
	this._dateCompleted = dateCompleted;

	}

	// Define class propertiers.
	Task.prototype = {

	// I set the new description.
	changeDescription: function( description ){

	this._description = description;

	},


	// I complete the task.
	complete: function(){

	// Make sure the task isn't already complete.
	if (this.isComplete()){

	throw( new Error( "TaskAlreadyComplete" ) );

	}

	// Flag as complete.
	this._isComplete = true;
	this._dateCompleted = new Date();

	},


	// I determine if the task is completed.
	isComplete: function(){

	return( this._isComplete );

	},


	// I determine if the task is open.
	isOpen: function(){

	return( !this.isComplete() );

	},


	// I re-open a completed task.
	open: function(){

	// Make sure the task isn't already open.
	if (this.isOpen()){

	throw( new Error( "TaskAlreadyOpen" ) );

	}

	// Flag as open.
	this._isComplete = false;
	this._dateCompleted = null;

	},


	// -- Acccessors for output and persistence. -- //


	getDateCompleted: function(){
	// ..
	},


	getDateCreated: function(){
	// ..
	},


	getDescription: function(){
	// ...
	},


	getID: function(){
	// ...
	},


	getIsComplete: function(){
	// ...
	}

	};


	// -------------------------------------------------- //
	// -------------------------------------------------- //


	// Create our existing task.
	var task = new Task( 1, "Buy flowers", false, "2012/07/02", null );

	// Mess with task.
	console.log( "Task open?", task.isOpen() );
	task.complete();
	console.log( "Task open?", task.isOpen() );
	console.log( "Task complete?", task.isComplete() );

	// Try to close the task twice in a row.
	try {
	task.complete();
	} catch (error){
	console.log( "Error:", error.message );
	}


	</script>
	</head>
	<body>
	<!-- Left intentionally blank. -->
	</body>
	</html>