Around the middle of February I completed a basic persistence and networking implementation for Fjord, then had to do other things for a month. Just recently I fixed Fjord to work with the latest version of the Node.js APIs.
Next project: I'm going to use Fjord in a Web Framework to be called "JSON-Mash".
I intend to show that JSON-Mash will be a great framework for rapidly building truly interoperable and truly scalable online and distributed functionality.
Here's how JSON-Mash will work.
Juggling Data Formats
In traditional Web Frameworks, the developer has to juggle up to five different data formats.
At the front end, you may be working in HTML or HTML chunks sent via Ajax. Then your domain logic may use object classes. You'll no doubt map those objects to relations in your database layer. That's three data representations (also known as Circles, Triangles and Rectangles).
But there may be even more: if you call out to integration points such as a search service or other API, you'll probably be using XML. And if you did application-level cacheing, you would probably consider casting your data into key-value form.
This is not unrealistic - at a current ThoughtWorks client, I was faced with exactly these five data formats - in an extremely simple application.
JSON-Mash will do away with all that. It uses JSON objects everywhere.
JSON-Mash sends JSON data to a script in the browser that builds the page declaratively from its understanding of a number of stable, generic JSON types. It uses Ajax and Comet to pull JSON chunks in, to composite into the page.
JSON-Mash uses Fjord to process its JSON: transforms, map-reduce, etc. It uses Fjord to persist objects in a JSON NoSQL database, and Fjord to provide shared JSON cacheing functionality with cache updating via Fjord's FOREST integration style.
Finally, if there's any external system to be integrated, that too will be accessed via an adaptor that converts its API, etc., into JSON-Mash stabilised JSON. There will be Twitter and Flickr adaptors at first, I should imagine.
JSON-Mash and Fjord
Using Fjord means that JSON-Mash treats its JSON as a first-class hyperdata type: lots
of little JSON chunks all with URLs and all linked up. I
that one day it may have the media type of "
application/fjord+json". JSON-Mash Nodes
communicate in the
Of course, the main benefit of using Fjord is that you get a great, declarative mashup language to describe your logic in.
Fjord is still very new, of course, so some goodness is yet to be rounded out. For example, it comes with a very basic, but highly improvable, NoSQL JSON datastore and already allows some powerful map-reduce and other query and transformation modes, with more to come.
Finally, Fjord gives a dynamic view of JSON data: caches get updates pushed into them and Comet pull will also come as part of the package.
CSI and SSI
Now, one of the great things about Node.js is that you can run the same code on the server as you run in the browser.
My previous attempts at doing things the JSON-Mash way have met with some resistance when I suggested building duplicate logic server-side to render pages statically, for accessibility and search engines.
I use the phrases 'Client-Side Include' and 'Server-Side Include' or CSI and SSI as easily-understood shorthand for this kind of page assembly from JSON elements.
This approach differs from "progressive enhancement" as long as you have both full CSI and full SSI to render your site. But you could also have a 'CSI-SSI slider', where an initial page is generated by SSI, then CSI takes over to fill in the funky stuff: the dynamic widgets and Comet-driven elements.
Users Exploring a Dynamic Web of JSON
The way JSON-Mash works is that you get a view into a hyperlinked Web of JSON data, and can explore it from any point outwards. In the CSI version, each JSON chunk is loaded lazily as it is encountered, then reloaded when it changes. Even the SSI version of the site would allow this form of exploration, although in a less efficient and dynamic way, of course.
In JSON-Mash, the user is also a first-class object; the stable JSON types also include a type representing the user. This user is driving their browser, subscribing to events on visible JSON page components via Comet, and POSTing their own user state to a server-side cache copy.
Hence, if that user state contains a message, you can get simple chat functionality, without any code, just by linking to a user and viewing them.
JSON-Mash is a Web Framework that will use, re-use, assemble, mash, transform, store, share, push, pull and render JSON from end to end and top to bottom; from Ajax to NoSQL.
SSI or CSI page assembly are very flexible ways of mashing up new functionality from multiple back-end sources of RESTfully-sourced, interlinked JSON data. And with cache updates telling SSI and CSI when the back-end data has changed, you get a very dynamic yet scalable system.
JSON-Mash will be a framework for rapidly building truly interoperable and truly scalable online and distributed functionality.