Re: Best way to feature-test?

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From	Gregor Kofler <usenet@gregorkofler.com>
Newsgroups	comp.lang.javascript
Subject	Re: Best way to feature-test?
Date	Mon, 16 Jul 2012 10:48:37 +0200
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Am 2012-07-16 02:50, perryv@gmail.com meinte:
> Hi everyone,
>
> I've been using the following technique to detect if a certain functionality is supported by a browser:
>
>
> if(document.someFunctionality) {
>      // Use someFunctionality
> }
>
> But lately, I've been reading that "document", "window" and other browser objects are "host objects", and host objects have their own rules and behaviors that depend on the browser and the platform. So it's possible that merely testing "document.someFunctionality" can throw an exception in some browser on some platform.
>
> So, in order to cover those cases, is it reasonable to do the following?
>
> if(typeof document.someProperty != 'undefined') {
>      // Go ahead and use the property
> }
>
> if(typeof document.someFunction == 'function') {
>      // Go ahead and invoke "document.someFunction()"
> }
>
> Or is it overkill?

Quite the contrary.

Some links for further reading:

<http://www.cinsoft.net/host.html>
<http://peter.michaux.ca/articles/feature-detection-state-of-the-art-browser-scripting>


Gregor


-- 
http://vxweb.net

Thread

Best way to feature-test? perryv@gmail.com - 2012-07-15 17:50 -0700
  Re: Best way to feature-test? perryv@gmail.com - 2012-07-15 17:54 -0700
  Re: Best way to feature-test? Gregor Kofler <usenet@gregorkofler.com> - 2012-07-16 10:48 +0200
    Re: Best way to feature-test? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-07-16 21:29 +0200
  Re: Best way to feature-test? Ivan The Not-So-Bad <1suf41n@yahoo.com> - 2012-07-16 13:49 +0000
    Re: Best way to feature-test? Tim Down <timdown@gmail.com> - 2012-07-16 08:42 -0700
      Re: Best way to feature-test? Ivan The Not-So-Bad <1suf41n@yahoo.com> - 2012-07-16 17:35 +0000
  Re: Best way to feature-test? Jim T. <x@y.z> - 2012-07-18 13:22 -0400
    Re: Best way to feature-test? Jim T. <x@y.z> - 2012-07-18 13:24 -0400

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