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I'm not sure at all who's still active in the server-side web development world, but it seemed best to reach out through the old channels in case some people are interested in reviving RIFE.
I've personally been busy with a lot of other projects during the last 7 years, ranging for high-performance clustered data tools to real-time musical instruments.
I'm now working at ZeroTurnaround on the LiveRebel product and am being confronted with the state of web development nowadays. To my surprise, in many ways the approaches in RIFE are still relevant and even the Play framework is lacking quite a lot of RIFE's simplicity and power.
So, a few months ago I started work to analyze what I want to keep from RIFE version 1 to build a fresh version 2: https://github.com/gbevin/rife. I took a little break to work on another quick pet-project in the meantime (http://uwyn.com/geco) but that's now all ready for launch.
The idea is to basically put a lot of things in question about RIFE and trim it down, throw away a lot of the junk that was accumulated and make the features very opinionated and targeted.
My initial plan of action is this:
I've started mocking up the new version of the template engine and took an initial stab at creating an Antlr 4 grammar. That sadly is really not working out so I've started work on a new custom parser.
One of my mistakes with RIFE v1 was that I didn't involve the community much during the development process, so I want to change that.
If you're interested in shaping what RIFE version 2 is going to become, please hop on the developers mailing list and say hi: https://groups.google.com/forum/#!forum/rife-dev
Hope to hear from some of you!
RIFE has a unique approach towards validation which is centralized around bean instances and not bean classes.
Instead of having an external validation service, each bean instance publishes meta data about its constraints. Every part of the system (validation, form generation, database structure creation, ...) will inspect the meta data and peruse it. Validation is an exception in that after inspecting the meta data, the results of the validation are contributed back for each specific bean instance as
Instead of implementing a container that keeps track of all the mappings between bean instances, their meta data and the validation errors, I decided that each bean instance will actually hold this data into fields. However, since people generally dont want to pollute their bean classes with framework-specific constructs, I created the meta-data merging facility. This automatically looks for a class with the
All this is very intuitive when you use it in practice and develop a database-backed website. RIFE's database layer doesn't use an entity container either but rather creates and populates new bean instances each time an entity is fetched from the database. This has the benefit of each thread having a dedicated version of the entity which can be manipulated without risking data races. Only when all the operations are finished, the entity is stored back into the database through an explicit save call.
The code could be like this when editing an existing
However, when using Terracotta (or something else, like a cache), you typically don't want every entity to go back to the database. Instead, you want to keep them in memory and only store certain parts into the database. So instead of having a database manager, you have some kind of in-memory service that is able to find and store entities.
Intuitively and naively you would replace the code above with the following broken code:
The problem relies in the fact that each and every thread will be working with the same instance of the
So, instead of retrieving the user from the service to modify it with possibly invalid data, you want to create a new instance of the entity that will be in local scope until the validation has succeeded. Only then you want to store it back into the service. This guarantees that your data is always correct and also allows perfectly concurrent access on users with the same identifier.
The correct code would thus be:
This had me scratching my head when I was bitten by the broken code above. However, if you think about it, it's perfectly logical. Working with in-memory containers is fundamentally different from working with relational database, where your data is stored independently from the actual objects that you're using. You have to remember that an in-memory container is a store too, and you don't want invalid or intermediate results to end up in there. However, this is what you risk to happen when you directly manipulate the fields of the instances that are already in the in-memory container ... but it's oh so tempting to do!
Joshua Hansen wrote a nice example of how to create custom meta data constraints and display dedicated validation error messages with RIFE. He also shows how easy it is to make RIFE/Crud display your validation errors for beans that use your custom constraints.
In case you want to learn more about RIFE, ask questions, chat a bit about what you've done, share experiences, etc., feel free to come the the BOF tonight that I'm organizing during the QCon conference in San Francisco. You can find all the details here:
The address is:
Westin San Francisco Market Street
50 Third Street
The BOF will be from 8:30pm - 9:30pm in the 'City' room.
We are also organizing a Terracotta BOF right before it, so if you're interested in that, you can come from 7:30pm - 8:30pm to the 'Stanford' room.
See you there!
I'm speaking at NFJS in London at the end of this month about RIFE and Terracotta. You can find the abstract of my session quoted below. The schedule looks very interesting and I'm excited that NFJS is finally taking place in Europe too.
If you're interested in going, you might want to click on the banner to the right or to use the promotion code NFJS-RIF660. This will give you a free Nintendo Wii with your registration (woohooo, I love my Wii!).
See you at NFJS Europe.
I also have another session about Terracotta in the real-world.
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