I have a running java application which has some APIs, but none of them follow the REST standards. You need to use separate APIs(some are XML/JSON based and others are SMTP based) to achieve CRUS operations.
I really love the MVC architecture and the strict RESTfullness of ROR, so I am thinking to write a API only ROR service using rails-api gem. Is it recommended to write wrappers like this over the existing APIs to provide better REST APIs?
Note: The existing APIs are very old and I don't want to rewrite them from scratch.
Whether or not it's "recommended" depends on your needs, your timeframe, the ROI, etc. There's nothing wrong with writing a RESTful layer over existing APIs, if that's what you're really asking.
I prefer a "regular" API over one that has multiple access methods, irregular access patterns, etc. If I have the time and resources, putting a layer of abstraction over complexity is almost always valuable.
Related
I have a project that involves both mobile and web clients. The mobile clients will mainly get content and post user updates, while the web client is mainly for creating content. As such, the web client and API share a lot of the same models and validation.
I am trying to decide the best approach in this case:
JSON-only Rails API + separate Rails web client that calls API.
Single Rails app with separation of API and client side (somehow).
The pro for me in terms of option N°1 is the separation of concerns, as I can work on the API while someone else do the web client. The con seems to be lots of duplicated code in terms of validation.
N°2 could make more sense in terms of reducing code duplication but it would get messy if more than one person is working on the same code base and setting up a process to resolve code conflicts is not something I want to do at this point since we're an early stage startup and want to get out something quickly.
Is there anything I'm missing?
The best practice is use ONE rails application for API and Web Interface
To separate those parts, just create a namespace for API like it's described there http://collectiveidea.com/blog/archives/2013/06/13/building-awesome-rails-apis-part-1/
Do it in one.
The con seems to be lots of duplicated code in terms of validation.
No, you would not have duplication the validation happens in the model, which is shared by your API <=> web controllers. Of course, you will have separate implementations for the actual authorization/session handling (if you have those), but these will not likely be duplicate but a bit different for your two access layers.
I have an EF model with about 200 tables, 75 of which I'd like to expose via REST in an MVC app. I started by adding a WCF Data Service (WCF-DS), pointed it to the EF context, and bam, I had the entire database mapped to REST URI's with full OData syntax support in about 2 minutes.
Next I tried to create the same REST URI space with WebAPI. When I tried to add a WebAPI OData Controller the first thing it asks for was a Model Class and when I was done creating the controller (and copying all the required ODataConventionModelBuilder code into the WebApiConfig) I only had one REST endpoint! My impression now is that WebAPI is not well suited to expose entire EF models with a lot of brute force.
So my questions:
Am I missing a way to map a bunch of WebAPI endpoints to a EF model in one fell swoop?
(Maybe T4 templates that build all the WebAPI code when I generate my EF model??)
Are there any compelling reasons to consider WebAPI vs WCF-DS to expose large URI domains?
(Some say that the benefits of WebAPI are to have fine grained control over each and every MVC/HTTP request but that seems counter-productive if the goal is to conform to the OData spec. I'm not sure I want to have 75 controllers and 1000's of lines of code that would tempt my dev colleagues to change one entity's behavior that would result in different behavior from other entities.)
(For cross cutting concerns such as security, caching, or performance throttling WCF-DS seems to have sufficient configure-ability with Interceptors and its DataServiceConfiguration class. Are there any features of WebAPI that would do better here?)
Thanks.
Update: I found this article by Julie Lermon that helps a bit: http://msdn.microsoft.com/en-us/magazine/dn201742.aspx
Since I have only exposed EF model using WCF DS, I can't comment on Web API questions. But we never really had a reason to replace WCF DS with Web API for our model because as you also noticed, EF and WCF DS play so nicely together that you basically get an OData feed for free. On a client side the situation is different: we started with WCF Data Services Client that is trying to mimic Linq to Entity Framework, but is has so many limitations that I ended up writing my own OData client (you can read about what made us unhappy with WCF DS client part here).
Coming back to server side: our domain was large, we had 80+ tables with almost 1000 columns. And we even supported all CRUD operations using batch updates (OData analog of transactions). While I would recommend to think twice before exposing database record update operations over OData protocol due to design principles, we haven't had any technical issues with that approach.
It is my opinion that Web API + OData extensions is highly overrated for a large majority or use-cases, and my argument is that OData is fundamentally data-oriented while Web API has come to become a great fit for general-purpose APIs, which include service-oriented APIs.
Your use-case is, I believe, a prime example of a very data-oriented layer since you don't seem to want to add much domain logic on this tier (server-side of this HTTP API). And WCF-DS works great for that, especially if you're merely wrapping an EF model which does 90% of the work for you (as you've already observed).
Of course it would be a different story if you were modeling more intricate processes at that layer (in that tier), so exploring both options like you did is always a very good idea. Normally the obvious choice should come naturally, either you'll be writing a lot of redundant code with Web API (go with WCF-DS) or you'll be fighting with WCF-DS's very rigid framework by playing with odd entities and not-very-RESTful OData actions (go with Web API alone).
Web API with its OData extensions stands somewhere in the middle, although it's not always clear what advantages it provides over custom WCF-DS providers. I guess it's nice for people who already know Web API or ASP.NET MVC, and may be a requirement if you want open source. I personally wouldn't debate on this technology with technical arguments, except for the few gotchas one should know about (but which have nothing to do with its design). I've ranted about all of this a while ago, should you want more, but I stress again that there are no hard truths in any of this -- discussing architecture and design is in no-trivial proportions a matter of opinions.
Update: WCF-DS was killed.
I'd like to use WebAPI as my API technology to:
Allow approved companies to enter/retrieve data in my systtem
Create a standard interface for my company's iOS/Android/etc. applications
Does anyone know of best practices for, and mechanisms used to implement, versioning of interfaces. Specifically, I don't want to break backwards compatibility if I make updates to my API. I'd like to know what versioning schemes people use and if WebAPI has any built in mechanisms supporting versioning without the need to set up routes/paths every time a new version is released. Any thoughts would be appreciated.
Update
After performing some research I think I know what I want to do, I'm not sure how to do it. Ideally during content negotiation I would like to use a media type passed by the user to specify which version of the API should be used (rather than hard-coding the URL) and hit the corresponding controller.
If you don't want the version to be included in the Url, the way to go is probably to implement IHttpControllerSelector. This blog post should give you a good starting point: Implementing API versioning in ASP.NET Web API
I recommend you take a look at Peter Williams' series of blog posts on versioning REST services. They explain the what and why. For the how, check out Mike Wasson's tutorial on how to create a custom media formatter.
I'm looking at building a simple login-based iOS application that needs secure access to create, read, updated and delete data from a MySQL database - with certain actions available to specific users based on roles.
I've done some research and it looks like I need to build a RESTful Web service which provides Web Services which the iPhone app calls to access the data.
I have very little experience of web services development, are there any books/tutorials that are worth checking out? Is it worth looking at a web framework, rather than start from sractch?
I've done some basic web development in PHP/Python so would prefer to build in that I think..given that hosting it would be relatively cheap..
Have done some basic C#/Java; would it be worth looking at these instead? I tried creating a simple ASMX webservice but most of the examples cite using a MSSQL server, not sure if that is the way to go though.
Use a framework. No point reinventing the wheel and giving yourself a headache. A good PHP based solution would be to use Drupal to build the backend using the Services module to provide data via webservices. Drupal is so flexible and so popular now, that you can get a lot of what you want done without any code at all.
Roughly:
Install Drupal 7 on a webserver according to the instructions
Install the Services module
Design the entities that will make up your MySQL database
Tell the services module how you want to expose things
Some examples of API calls are here.
A case study of someone else who has used Drupal as the backend for iPhone/Android is here.
You will have a learning curve to get your head round Drupal, but you'll have one anyway to get your head around webservices and the benefits you gain from having everything else Drupal offers are enormous, e.g.
The difficult bits are already done for you, so the amount of code will be massively reduced, if you even need any at all
Using Drupal's hugely flexible entities system, you can design a flexible and extensible mysql database scheme using the web based UI, which will be ready to work with any of Drupal's other modules, so you can expand add features with minimal effort in the future
There's an enormous community of people who can help you and the forums on drupal.org are very active
You would have a great UI for users, in case you ever need to give them access to their data through a normal website interface. Drupal has loads of pre-built themes (I recommend Omega) which look awesome and again, little to no code is needed to get a whole site ready made along with HTML5, standards compliance etc.
Drupal provides you with ready-made modules to provide access control via roles, as well as everything else you can imagine e.g. managing a mailing list for your users, providing you with usage statistics, admin interface for user and role management etc.
Drupal use is exploding globally and there's a serious skills shortage, so you'd be even more employable :)
First, it's not compulsory that you use a REST web service. It's just that WS si more or less standard for web-based applications.
I'm not really familiar with PHP, but in python you have django-piston. On the IOS side you have restkit to pair the server with.
What I could say from my experience is that writing a prototype in django is quite easy and you can definitely use this to develop your app.
I am new to both Django and Rails. I am thinking of developing an Web 2.0 style application and is planning to expose Restful services, which my UI tier would call to make CRUD operations (Something similar to ADO.NET Data services)
I am yet to decide on the platforms and is looking for some advice on which one to side develop on?
I am currently thinking of Ruby on Rails or Django.
The benefit of using DJango / Python is that I can move to google AppEngine in future with some code changes, but on the down side I hear DJango is not RESTful.
I am also new to both Ruby and Python. So, what would be your advice on which platform to use?
Well if you want to couple the view and controller with REST then you are right that django is not RESTful, because with django you would have to (de)serialize django objects and manipulate that by yourself in the front end using your favourite javascript framework. Saying that, if your only concern is to send and receive data RESTfully without caring how to do it, then django should be sufficient for you since you've already got your heart for it.
Django is fine for REST applications. Rails claims to provide some functionality to that makes REST easier, but it is largely inaccurate - things like human-readable URIs don't really matter to REST. Rails auto-generates POST/GET/DELETE/PUT stuff for you, but it's just as easy to do in Django too - and it really doesn't have much to do with REST, either, it's just proper HTTP usage.
REST is a general type of architecture, it has very clear constraints, but there is no one, single way to do a REST application. This is a good discussion by the architect of REST, Roy Fielding, on some common misconceptions: http://roy.gbiv.com/untangled/2008/rest-apis-must-be-hypertext-driven
I recommend Python and Django, but not for REST-related reasons. (Better documentation, a saner API with Django, less nasty monkey patching and black magic, less coupling, etc)
A RESTful interface is used for building distributed applications. Does your UI tier and services tier really need to be physically separated? Seems overkill to me.