Question

Me and some friends are going to develop a web site with playframework and a mobile application (android and iphone). So we need to make some webservices for the mobile application(CRUD). So we thought about using this web services in our playframework application instead of wasting time and creating the CRUD with anorm(writing all the sql requests).

Well, I’m here to ask for your opinion. Is this a good thing to do ? What’s the best advised method here ?

Thank you.

PS: the web services are automatically generated with Netbeans from our database.

Answer 1

There are various reasons why I would advice against this approach.

A general design rule is not to expose your internal data model to the user. This rule comes in many flavors in which the layered architecture is probably the most known one.

In detail there will be issues like:

1. Tuning performance: This is hard to achieve because your have no, or not much control over the generated web services. When your application is really taking of your will suffer from this limitation
2. Access the service: I don’t know whether you generate RESTful web services or WS-* ones. The latter will get you in trouble when accessing them via iphone.
3. Design Play vs. synchronous web services: Also somehow related to performance is the issue that the generated service is likely synchronous, blocking, which does not fit well with the non-blocking approach which the play framework is taking.
4. Abstraction level: Because your database is based on sets but your business model is likely not, you will have issues developing a decent client, tuning the performance, doing proper validation, security, etc.
5. Authentication, authorization and accounting: Hard to do because the database only knows the db system users
6. Change: What if you change your database model? Will the generated services continue to work? Do your have do adopt them event if you just add a column?
7. …

Some of those reasons do overlap, but I think the general problem should be clear.

Instead of this approach I would recommend the following. Develop a RESTfull endpoint for your app, which is not that hard to to. This is the external contract against which the clients should be developing. play-mini for example has a very need, Unfiltered based, API to do this. While doing this, focus on the operations your app really needs. CRUD in general is a bad model when thinking about production ready software.

How you access your database is another decision your have to make but probably it is not that important because it is not your external contract so your can change it when your have the need for doing so.