Wednesday, November 7, 2007

ActiveGrid is useful for web-based application building, but like so many mashup tools, you've got to have a fair amount of technical know-how

You'll notice from the title that I'm going to review ActiveGrid by WaveMaker. I wanted to review either Denodo, JackBe or AlchemyPoint by Orchestr8, but both Denodo and JackBe declined to allow me to evaluate their software, and Orchestr8 needs to publish some more documentation before I can do a good evaluation.

Why couldn't I test drive Denodo or JackBe?

Denodo declined because they sell enterprise middleware that requires some hand-holding to install and understand. They don't allow web downloads at all, let alone downloads by potential competitors. They did offer me the chance to participate in a directed demo, but having been in the software business for a long time, I just don't trust demos. I need to dig in and get my hands dirty. I want to thank them for making the offer, however.

JackBe was more straightforward. Serena is a competitor, and they aren't knowingly going to hand over their software to someone who could have malicious intent. That would be me, I suppose.

Fair enough. I'll just have to sign up under a different email address and company name and get my hands on it that way. Perhaps I'll use my Second Life avatar. Better watch out for a download request from Chuck Malibu, JackBe. (Note: This is a joke. I would never do such a thing, even to support my blogging habit.)

So while I can't talk to you about Donodo, JackBe or AlchemyPoint, I can talk to you about a surprisingly interesting web application building tool called ActiveGrid. WaveMaker is the company name, although as little as a week ago the company name was ActiveGrid, just like the product name. I'm not quite sure why they changed their name, but as long as they didn't change the tools, this review should still be accurate.

What is ActiveGrid?
ActiveGrid advertises itself as a Web 2.0 platform (who doesn't?) allowing non-technical or business-oriented people to build their own AJAX-based RIAs and mashups. Some of that is true, and some is a bit of a stretch. It's true that you don't need a lot of technical know-how to build data-based applications with highly interactive AJAX-driven interfaces, although some familiarity with the workings of a DBMS is necessary. When I started to build mashups, well that required a bit more technical know-how, which I'll talk about later.

ActiveGrid's application model is based on a database with a web front-end driven by a BPEL process engine. It reminds me strongly of the old Access-driven applications we built back in the 80s and 90s. Start with a database, add some user interfaces and some Visual Basic to manage the business logic, and there you have it, a home-built application. Of course, ActiveGrid is quite a bit more sophisticated.

I used ActiveGrid to build an application that used the various RSS feeds and REST interfaces I defined in OpenKapow. (See my earlier post.) It was easy to assemble the screens as long as I used the defaults. They do a fairly good job of putting the widgets, data fields, etc. on the display in a visually pleasing way. They have a small selection of style sheets which were adequate. Of course, just as with QEDWiki, you can use your own style sheets.

Building ActiveGrid Web Pages is a Mixed Bag
I liked a lot of the page-building features. Selecting service fields to use on a page was quite easy. I didn't need to map the fields to page elements, ActiveGrid did all that for me. One very nice feature allowed me to take individual pages I created and, using AJAX techniques, quickly aggregate them into a single page. I liked that a lot.

Some things I didn't like about the page builder. What I want, and what most web-based application page building tools provide, is a visual modeling tool with a drag and drop interface allowing me quickly to mock-up the page. That's not how GUI development works in ActiveGrid. Setting up page formats reminded me strongly of the way we built XWindows/Motif interfaces back in the day. Trust me, it was tedious and time consuming.

BPEL for Page Orchestration and an Intuitive Event Model
ActiveGrid use BPEL for page orchestration, which is an interesting although unorthodox choice for an interactive application. BPEL is usually associated with the WS-* stack for web service orchestrations, not with human workflow. They've done a good job of making it work by unifying their service model. Everything is a service. A call to a RSS feed is equivalent to a SOAP call is equivalent to script is equivalent to a database call. It's an interesting approach and one that works well. I found their event model, which they use to control page flow, to be easy to understand and easy to use. They only have synchronous events, but that's a small price to pay for simplicity. BPEL supports asynchronous events, so perhaps they will them in the future.

For Mashups, Better Get Some Expert Help
Now let's talk about building mashups. ActiveGrid absolutely qualifies as a tool for building business mashups. They aggregate data and visual elements into a unified end-user experience within a process-centric framework. However, just because it is a business mashup tool, it doesn't follow that ActiveGrid is a tool for business mashers. In fact, I'd say that ActiveGrid requires quite a bit of technical savvy to create mashups. More savvy than we can expect from your average business analyst-turned-masher.

As I've hinted earlier, you can call many types of services from within ActiveGrid. A call to an RSS feed is equivalent to a SOAP call is equivalent to a database query. From my perspective as a business masher, I agree with this approach. Why should I care whether my service is REST, SOAP, RSS, POX or just a database call. Admittedly, I need to know the type of service when I import it, but after that it's just inputs and outputs.

But, and this is a huge 'but,' when it comes time to aggregate these services so they can be used to present a common interface, we come to a real problem area: Field mapping and parameter passing. I can only say that field mapping and parameter passing within ActiveGrid, well, sucks. It's likely not their fault. I don't know any application builder, especially one based on BPEL, that does a good job with field mapping and parameter passing. When I had to pass parameters into a service call, it took me quite a while to figure out how to do it. In fact, simply following the steps in their 'getting started' application to pass a parameter from one page to another was confusing and took me several tries before I understood what they were doing.

Let's just say that ActiveGrid didn't seem to take a lot of trouble to hide the complexity of the BPEL field mapping monstrosity from their end-users. No graphical drag and drop, no suggested mappings. Not even pop-up help so you could read the help and look at the interface at the same time. Just a lot of steps to define input variables, output variables and a really bad interface to define the logic that associates the two together.


Botom Line

Business mashers can use ActiveGrid to build web-based applications quickly and easily. With some understanding of how databases work, it's quite simple to build highly interactive and appealing applications. When you want to turn them into mashups, however, you'd better get some serious help from your applications development organization because it's neither quick nor easy.

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