A Web-based app builder with a Microsoft twist
- — 24 October, 2008 08:07
After the form is built, though, comes a brick wall. There's no simple way to add your own custom validation to the server side of the application. Caspio offers a number of suggestions for how to add JavaScript to the client side, but you can't tweak any of the application logic on the back end.
This will be frustrating to a programmer who wants control over every layer in the stack, but it's easy to see why Caspio locks the server down. I've played with one reporting tool that lets you add arbitrary Java classes into the reporting logic. It's slick and programmer-friendly, but it fails badly when something goes wrong. The tool offers to compile your Java for you, but if it finds an error, it fills the screen with a stack dump. Caspio, like all of these server-based tools, must anticipate the worst that a user can do, which usually means endless loops and other simple mistakes. Exiling extra logic to the client is a simple and fairly elegant solution to malicious code, though Caspio's JavaScript customization comes with fine print: "Caspio is not responsible for the correctness, compatibility or applicability of these functionalities."
Here is where the counterrevolution starts losing punch. Pushing the logic to the client can make security much harder because a malicious person can hijack any extra JavaScript you add to your client. I don't think that this is a real concern for most of the applications built on top of Caspio, but it's something to keep in mind. Caspio does offer a good number of security features, including the option of encrypting your development sessions with SSL.
Loaded and locked in
The lock-in with Caspio can be brutal as it is with most similar tools. Once you build your application in Caspio, you can't really move it. This makes sense, given the business model, which charges nothing up front and a monthly fee afterward. You pay only if your application is successful, and eternal devotion to Caspio is the price.
The costs, though, aren't steep. Caspio encourages unlimited users and measures the sophistication of an application by counting the number of forms and the data stored in tables. By contrast, Coghead and WuFoo count the full-time users, although both are trying to tweak their model to avoid charging for users who visit only occasionally. Caspio avoids the distinction between full-time and casual users entirely.
What is truly surprising about Caspio is how much it feels like a Microsoft product. While there are many programming idioms common in Web applications, Caspio sidestepped most of them and built something that will look very familiar to Microsoft Access users. I did a double-take when I pushed the "edit" button for a page because Caspio took me back to the beginning of the page's configuration wizard. You may be working in a Web browser, but It's just like using Windows.
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