Determine whether a URI scheme is enabled

[Chris Davies]

I'm curious. I'd like to determine whether a particular URI scheme (the
"ftp:", "news:", "http:" part) is available within the user's browser.

For example, consider this HTML snippet:

Telephone us on <a href="tel:[phone]xxxx">0113 393-xxxx</a>

I could extend the tag with an onClick handler that displayed an
alert() box (or similar), but ideally I'd like it only to do that if
the underlying URI scheme couldn't be handled by the user's browser.

Thanks,
Chris

[David Mark]

On Oct 3, 9:11 am, Chris Davies <[e-mail]:

I'm curious. I'd like to determine whether a particular URI scheme (the
"ftp:", "news:", "http:" part) is available within the user's browser.

For example, consider this HTML snippet:

Telephone us on <a href="tel:[phone]xxxx">0113 393-xxxx</a>

I could extend the tag with an onClick handler that displayed an
alert() box (or similar), but ideally I'd like it only to do that if
the underlying URI scheme couldn't be handled by the user's browser.

You are out of luck there.

[Thomas 'PointedEars' Lahn]

Chris Davies wrote:

I'm curious. I'd like to determine whether a particular URI scheme (the
"ftp:", "news:", "http:" part) is available within the user's browser.

I could extend the tag with an onClick handler that displayed an alert()
box (or similar), but ideally I'd like it only to do that if the underlying
URI scheme couldn't be handled by the user's browser.

You can do something along

function navigateTo(s)
{
try
{
window.location = s;
}
catch (e)
{
window.alert("Unsupported URI scheme: " + s.match(/^[^:]+/));
}

return false;
}

<a href="foo:bar" onclick="return navigateTo(this.href);">...</a>

But you can't suppress an error message displayed by the UA already.
PointedEars
--
"Use any version of Microsoft Frontpage to create your site. (This won't
prevent people from viewing your source, but no one will want to steal it.)"
-- from <http://www.vortex-webdesign.com/help/hidesource.htm>

[Chris Davies]

Chris Davies wrote:

I'm curious. I'd like to determine whether a particular URI scheme (the
"ftp:", "news:", "http:" part) is available within the user's browser.

Thomas 'PointedEars' Lahn <Po*********@web.dewrote:

You can do something along

function navigateTo(s)
{
try
{
window.location = s;
}
catch (e)
{
window.alert("Unsupported URI scheme: " + s.match(/^[^:]+/));
}

In FF the "No program for this URI scheme" error (paraphrased) can't be
caught like this, so sadly I'm no better off.

Thanks for the thought.
Chris

[Thomas 'PointedEars' Lahn]

Chris Davies wrote:

Chris Davies wrote:

>I'm curious. I'd like to determine whether a particular URI scheme (the
"ftp:", "news:", "http:" part) is available within the user's browser.

Thomas 'PointedEars' Lahn <Po*********@web.dewrote:

>You can do something along

Please read the FAQ on how to quote correctly in Usenet.

> function navigateTo(s)
{
try
{
window.location = s;
}
catch (e)
{
window.alert("Unsupported URI scheme: " + s.match(/^[^:]+/));
}

In FF the "No program for this URI scheme" error (paraphrased) can't be
caught like this,

It can be considered a great advantage here to be capable of reading.

| But you can't suppress an error message displayed by the UA already.

so sadly I'm no better off.

As I said: you can't do this.
PointedEars
--
realism: HTML 4.01 Strict
evangelism: XHTML 1.0 Strict
madness: XHTML 1.1 as application/xhtml+xml
-- Bjoern Hoehrmann