[Laszlo-dev] Dealing with unsupported HTML/CSS features in DHTML

[P T Withington]

There is (perhaps not documented?) canvas.capabilities, which is  
intended to cover this.  It's initialized from LzSprite.capabilities,  
which is initialized on a per-browser basis.  So, I think you just  
need to add to that.

On 2009-09-02, at 06:20, Raju Bitter wrote:

> I got a good comment on my last blog post showing the CSS text- 
> shadow features.
> http://openfuture.rajubitter.com/2009/08/25/openlaszlo-dhtml-css-3-demo-to-flash-or-not-to-flash-is-no-question/
>
> A guy called Mike said: "Also, I’ve rarely encountered a cross- 
> platform issue with the Flash Player, which is one of the many  
> reasons that developers use it. The DHTML/CSS version above doesn’t  
> display for me in IE7 (I just get the spinning “Powered by…”) but  
> the Flash below it does."
>
> I thought about that and came to the conclusion - that even for  
> demos showing the features of HTML 5 and newer CSS standards - I  
> don't want IE users to only see the spinning "Powered by...".
>
> I added some code to the demo I built, and now - based on the  
> browser version - you'll see the following message if you access the  
> application with an old browser or IE:
> <OpenLaszlo-CSS-BrowserCheckWarning.png>
>
>
> That's a much more positive way of informing the user that his  
> current browser doesn't support the features required for this app.  
> But I'd be interested in your oppionion, how should we handle  
> unsupported browsers for DHTML demo apps, especially in future  
> releases of OpenLaszlo? I thought of a class where you can register  
> which capabilities your application needs for the full user  
> experience, with a rating for importance: some features could be  
> left out, and the application doesn't look as good. Some other  
> features might be required, and then the user will have to access  
> the app with a different browser.
>
> For technically interested folks we could have an info button on the  
> warning message, giving more information about what feature is not  
> supported in the current browser.
>
> Of course, all of this is not for consumer facing applications in  
> production, more for the OpenLaszlo demos and docs. In production,  
> I'd just check the browser and capabilities, and then deliver an SWF  
> version for the older browsers.