Flash vs JavaScript for interactive maps_问答_开发者

I am developing a web application that is supposed to display land traffic in real time in any part of the world. For a couple months I've been developing it using JavaScript and OpenLayers (http://www.openlayers.org) framework.

Unfortunately, this solution appears to be inefficient. There are hundreds (200-300) of objects on the map that are updated every couple minutes. The sheer operation of refreshing and rendering them takes significant amount of time that makes the application less usable (slow responsivity to user actions).

At the moment I am considering changing the technology. Adobe Flex seems to be the most reasonable solution. There is at least one application written in it that does similar things to mine (http://casper.frontier.nl/).

However, I have a couple of concerns regarding Flex:

can it be easily integrated with the HTML/CSS/JavaScript based part of the application (for example, the graphical interface should be coherent when it comes to styles and colors)?
I get an impression that with latest browsers (mainly Chrome 9.0) JavaScript and CSS becoming more efficient. What are the chances that in a couple of months JavaScript+CSS will make it possible to implement efficient, flash-l开发者_StackOverflow社区ike rich internet application? (A note is needed here: famous Canvas tag is not a solution for my problem, at least not for now. Rendering objects on map with canvas proved to be less efficient than with traditional SVG because the size of the canvas is really big - a whole browser window)
What are the chances that Flash technology will be abandoned (Apple policy, HTML5 growing support etc.) in not-so-near-future (a couple of years)?
There is a possibility that my client would like to view this application on mobile devices, including iPhone.
Any other solution for web-based interactive maps?

Can anybody address these issues?

Lazy comment repost:

I've used Google Maps JavaScript API + a custom canvas tile layer (see here and here) to draw maps with 10k+ markers, really quickly. Perhaps you just need to rethink your particular approach rather than totally rewriting your maps.

JavaScript running on a modern browser (say, IE7 or later) should easily be able to handle 200 or 300 object updates every few minutes. Granted, if you want to do all 300 updates at the same time, things might get a little slow. But if those updates occur spread out over that period, then you shouldn't have any trouble.

There are Asteroids games and 3D shooters written in JavaScript and that are very playable. They do dozens of updates per second.

I would suspect your framework (I know nothing about OpenLayers) or the way in which you're doing the updates before I suspected the platform.

My experience with Flash has been less that positive. Although it will interoperate with JavaScript, there are some strange edge cases that will trip you up. And my experience is that it's almost impossible not to trip over those edge cases unless what you're doing is truly trivial. And, of course, the lack of Flash support on the iPad and iPhone will make supporting those platforms impossible.

I think it's unlikely that Flash will be abandoned any time soon, as there are too many customers who continue to believe the silly notion that Flash is the way to build interactive Web apps. Although that was almost certainly true four years ago, browsers, computers, and JavaScript techniques have advanced to the point that the only use I currently have for Flash is to play video. And that use will go away in the next few years when HTML5 video becomes more prevalent. With Google's WebM video format and the expected high-quality tools to build WebM, Flash becomes almost irrelevant as a movie player, except for older content.

My advice would be to take a long hard look at your current implementation, study some other JavaScript applications that do frequent updates, and determine if it's really the platform rather than the way you're using it that is causing your performance problem.

No idea how many objects you can manage and update in js, but in my company (flashmaps.com) we have built flash-based maps handling many thousands of objects. The key issue in many cases in fact is that the map is completely overlapped by the markers. We use to recommend filtering the markers in those cases. We have a huge experience in building flash/flex-based maps, so on't hesitate to ask me any question on that.

By the way, I don't think Flash will get out of use soon. Apple's strategy on controlling iPhone/iPad apps (the real reason behind Flash banning) is causing a lot of trouble to web developers, that need to create specific versions of their websites for these devices, it's crazy. But I'm sure Apple will permit Flash, someday... Probably when many other tablets hit the streets supporting Flash. We'll see.

The awesome thing about MVC architecture is as long as you keep your domain logic separate from your business logic and UI, then it's relatively easy to create platform specific apps that access the same data. For example, you could build the same UI to run in the web browser (via html/javascript or flash player), on the desktop (via Air), and on an iPhone/iPad (via iOS) that all connect to the same server-side scripts. It's all a matter of personal choice which platform you choose. If a platform happens to fall out of fashion in the future, then you simply create a new UI on another platform.