First of all, let’s clarify a couple of things.
1. This post is not intended to list “bad ways” of thinking about REST, but to list the actual way people really think about it. Some of them are perfectly correct per REST constrains.
2. From articles, presentations, discussions and the like, I extracted commons ways of thinking, and tried to categorize them. So, this is a totally subjective classification.
So, let’s start.
People know about REST. Many are trying to get into the REST world for the first time, some other have more flight hours, still not so many had read Roy’s dissertation. Even more, some of the ones that actually read the dissertation, may think about REST in different ways.
Usually, when in a discussion, the same concept may be understood differently by the participants, which yields in non-useful conclusions. This may be actually true about REST. That is why I composed the following list of “ways people understand REST”. The list may help the reader to find out where he stands in understanding REST, and how may other people understand it. Also, it may show how some people is using REST.
First, an cautionary word: the names I use are not intended to make fun of people, but to be easy to remember.
The list is divided into three major groups: The API makers, the Mappers and the Fad Followers. This last one may seem a bad one, but it is actually a normal one, trust me many people fall in it.
Then, each group contains categories. Those categories may be present in more than one group, since the characteristics may fit both groups. Finally, people may fit in more than one category, since the work is complex in the world of REST to reduced to just one characteristic.
Here is the list.
Major Groups 1: API Makers.
People in this group I find them everywhere. Most of the time they have a system, usually not built thinking on REST at first (REST as an afterthought), and they want an API created to access that system. They usually think about REST like an API making technique or recipe, for the web.
- URI Jugglers. These are the ones that think REST is all about creating URIs, and nothing more. So their discussions are solely focused on URIs, and their presentations are about URIs definitions. One way of spotting this category is when the application API is documented as a URI construction process using templates
- RPCers. This group think REST is a way to map RPC in disguise using URIs in a web API. The most of them don't know they speak RPC at all. Easily spotted when you see the API defined as a set of calls using a URI construction. Most typical is a URI format that includes the actual method name or action, followed by several parameters. There are many of them coming from SOAP based web services (the RPC kind), that made the change believing is easier to define the RPC call in a simple URI than using the complex SOAP envelope.
- Exposers: This type is repeated below. Those are the guys that think you need to expose things in REST using resources. So REST is an API for exposing things on the web. They usually look for objects or domain entities, but mostly processes or methods, and expose them using a URI formatted call. The slight difference with the RPCers, is that the exposers may not use RPC, but still expose the processes and entities through an API.
- CRUDers: Another repeated group. They think REST is a web API for CRUD. The similarities of the HTTP operations and the CRUD ones, plus the reference of resources as Data elements, support this way of viewing REST.
Second Group: Mappers.
This other group may use the API idea, but they actually think REST is a way of representing things and thus the work to be done is to map everything using that new way. Interesting?
- CRUDers. Again, the idea is that CRUD operations can be mapped naturally to HTTP operations, and that makes it RESTful.
- HTTPers. They believe REST is HTTP. Deep enough. This category is hard to spot, since many people talking about REST implementation may talk much about HTTP, but think REST is far more than just the protocol.
- Exposers. Again too. They usually try to map all classes, data entities, elements into resources, and then call their systems RESTful. This category includes people that take into account REST constrains, and also people that just maps the domain to resources.
Third Group: FAD followers.
This is a group that is identified by themselves. That is, they expose what they think explicitly. Usually, they tend to follow a lead or the current business idea.
- Standard Haters: Here you have all those that think Standards are evil and that REST is an anarchy where you have the freedom to do whatever you like, so they follow REST doing whatever they want.
- KISS lovers. These are the ones that like things to be simple. And someone told them REST is easy, so they follow doing easy things with URIs. There are lots of URI jugglers in this group. People here may not follow all REST constrains when they get complex enough. The idea is to keep the API or system with not much complexity.
- Servicers. They think Services is good, and someone told them REST is a way to do services without SOAP. So they follow. There are several RESTFull service creation techniques. Many RPCers in this category too.
- BuzzWorders. This is a vast majority. They like buzz words, so they follow REST just because it is cool and all people talk about it.
Is there some one I'm missing? Well, yes, probably the group that knows REST as it actually is and understands it. That may be a one person group (yes Roy).
What do you think? Do you find yourself in any of those groups? Which other category may you add?