I am about to begin a web application. Before I begin, I would like to get some advice as to what the best work flow/order is for creating a web application such as this.
My project will consist of a server-side with PHP and MySQL. The client-side will be XHtml, CSS and jQuery. There will also be AJAX used.
I’m sure that it can depend on certain situations, but, overall, what is the best order for developing a project with these credentials?
Should I start developing the server-side first? Or should I begin with the client-side? Or should I do both at the same time? What about the database – should that be a first priority? Then perhaps the DAOs?
Start with the data first. The server-side data is the persistent, essential core of the application. If this data model isn’t right, you have nothing.
You should be able to unit test the data model to prove that you have the right attributes and relationships. This doesn’t require much. A few test cases to insert, update and query.
You will support that data model with back-end processing.
This, too, should be unit tested to demonstrate that it works and does all the right things to your data model. This will be a bit more complex, since this processing is the application.
Then you can think about the data model as exposed by web services to Ajax.
This, also, is testable to prove that the JSON does the right things. This testing is often fairly complex because this is what the GUI front-end relies on. This has to be right.
Then, once you have that Ajax data model worked out, you can write the front-end GUI.