# What’s the big fuss about JavaScript about?

webtech @ 08 August 2011

(warning: I’m probably either dating myself, or making myself look like a dolt, or possibly both….but here goes 🙂 )

In case you haven’t already read my about page (and if you haven’t, well I can’t say I blame you), I’ve been in the software business for *gulp* about 20 years now.  So my perspective is either that of a wise old sage, or of an old curmudgeon when it comes to what I perceive as the latest craze around JavaScript all over the place.  By “all over the place” I mean at each of the three tiers in a traditional three-tier architecture:

  • Client
  • Server
  • Data

Back in the old days (like 2 or 3 years ago), the only place people wrote alot of JavaScript was at the client, which made a ton of sense if you were going for reach over richness since anyone with a browser of reasonable capabilities could use your UI.  Over the last year or so, even the richness argument has started to fade with the advent of HTML5 and CSS3, which allow you do do all sorts of wizzy and responsive UI’s in the browser.  The penetration of these technologies hasn’t gotten to the point *yet* where a developer can just make the bet on JavaScript, but that will change in the next year or two (maybe even faster if your demographic is hip enough to predominantly use Safari or Chrome).  There’s also the little matter of JavaScript being the only game in town if you’re trying to write code for a browser unless you want to take the bet on Flash/ActionScript.

On the server, you could use JavaScript if you wanted, using something like cscript on Windows, but not alot of developers went that route since there were other languages (like C++, Python, Perl, C#) that were better integrated with the platform and arguably richer and certainly more performant.  Now that node.js is around and taking off, the integration + performance arguments for non-JavaScript languages has started to wane, so developers have another tool in the toolbox if you will.

And on the data layer, I’m not aware of any options (and maybe even desire) to use JavaScript for querying before things like MongoDB came around.  With Mongo, you can use JavaScript to query your data as well as do filtering and pivots on the data inside the DB itself.  The idea of running code inside the database process, for either filtering or map/reduce like functionality is a powerful one and similar in concept to what Microsoft added to SQL Server when they added .NET coding inside the SQL Server process.  What’s new with Mongo is the ability to use JavaScript, at least its new to me, maybe there were other database platforms that were supporting this before, but the point for this post is how JavaScript is permeating the other levels of an architecture, and since Mongo is rather popular these days, its a good example to consider.

Ok so back to the question…why is JavaScript getting such traction in more places lately?  It’s clearly not the only game in town on the server or in the data tiers, those layers have existed and exploded for years using other languages and tools.  It’s not for performance, since JavaScript, as an interpreted language, isn’t going to be faster than say C++.  This leaves me to think it’s because of either:

  • interoperability
  • usability

Let’s look at the usability case first, since it may be a quicker discussion.  Usability is largely a factor of individual developer preference, that’s one of the reasons why we have so many different programming languages around today.  Of course the usability case could be made for it on the server and data tier if you’re at a company and either already have some JavaScript programmers (who develop your web application client), or need to hire a bunch of JavaScript programmers to develop your web application client.  The premise here is that you already need to know JavaScript to write the client, so why not leverage the same skills on the server and data layers?

There’s a more interesting conversation to be had around interoperability.  Since there is lock-in for JavaScript at the client layer, and data serialization formats like JSON make passing data around alot easier, it’s natural that you would like to use the same language, and possibly even code, on the server and data layers to get the most efficiency out of your developers.  XML has long been thought of as the way to get data across systems in a platform agnostic manner, but the fact is that while XML is expessive, it’s also rather heavyweight and requires clients to do more parsing than when handling JSON (since JSON can just be eval’ed into a native JavaScript object).  On the server-side, there’s been more built-in library/language support but invariably it still requires more parsing (I think) because that data format -> native object translation isn’t guaranteed like it is with JSON.

So to summarize, it seems that “the fuss” about JavaScript all over the place is really about efficiency (where developers are the resources being optimized), which makes sense as long as projects that aren’t staffed with JavaScript programmers from the start, understand they’ll be making tradeoffs if they pick platforms like node.js if they don’t already have JavaScript programmers on staff.  Of course the good news is for JavaScript programmers, your skills should be even more in demand now 🙂


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