Hi, I'm having trouble comparing strings of different types in Java
Script
The two strings are equal when displayed in an alert popup but the
"==" condition fails

The two types are the following
1.
nsIURI.spec
http://developer.mozilla.org/en/docs/nsIURI#Attributes

and

2.
http://developer.mozilla.org/en/docs/nsIScriptableInputStream:read



i receive a URL through nsIScriptableInputStream.read() and attempt to
compare it with nsIURI.spec

In this sample code, i pass in the nsIScriptableInputStream.read() as
the "url" parameter, which is then compared to :
http://developer.mozilla.org/en/docs/Code_snippets:Tabbed_browser#Reusing_tabs
I print out a alert message of the "url" and
currentBrowser.currentURI.spec and they are equal according to the
alert pop up but the "==" condition fails.

I have tried using this interface to convert the Read in string to
autf8string and then compare with nsIURI.spec but no luck:
http://www.xulplanet.com/references/xpcomref/ifaces/nsIUTF8ConverterService.html

should the above work?

EricL84@gmail.com wrote:
> i receive a URL through nsIScriptableInputStream.read() and attempt to
> compare it with nsIURI.spec

A better approach would be to use the IO service to convert the input to 
a URI 
<http://lxr.mozilla.org/mozilla/source/netwerk/base/public/nsIIOService.idl#75> 
and then use nsIURI::equals 
<http://lxr.mozilla.org/mozilla/source/netwerk/base/public/nsIURI.idl#173> 
to compare the two:

let ioService = Components.classes["@mozilla.org/network/io-service;1"].
                 getService(Components.interfaces.nsIIOService);
let uri = ioService.newURI(myScriptableInputStream.read(), null, null);
uri.equals(currentBrowser.currentURI);

-myk

On Mar 12, 1:45 pm, Myk Melez <m...@mozilla.org> wrote:
> Eric...@gmail.com wrote:
> > i receive a URL through nsIScriptableInputStream.read() and attempt to
> > compare it with nsIURI.spec
>
> A better approach would be to use the IO service to convert the input to
> a URI
> <http://lxr.mozilla.org/mozilla/source/netwerk/base/public/nsIIOServic...>
> and then use nsIURI::equals
> <http://lxr.mozilla.org/mozilla/source/netwerk/base/public/nsIURI.idl#173>
> to compare the two:
>
> let ioService = Components.classes["@mozilla.org/network/io-service;1"].
>                  getService(Components.interfaces.nsIIOService);
> let uri = ioService.newURI(myScriptableInputStream.read(), null, null);
> uri.equals(currentBrowser.currentURI);
>
> -myk

Thank you myk.
I had actually implemented your method previously, but it seems that
if the data read() in does not contain "http://" it causes in error.
This was a reason i wanted to avoid converting the input to URI.  Is
there a way around this?

However, I found the reason for the failed comparison between the
strings.  The data read in contained an "\n"  end of line character!

Thanks
Eric

EricL84@gmail.com wrote:
> I had actually implemented your method previously, but it seems that
> if the data read() in does not contain "http://" it causes in error.
> This was a reason i wanted to avoid converting the input to URI.  Is
> there a way around this?

If you know that strings without a scheme are http:// URLs, you could 
simply check for the presence of a scheme and prepend "http://" if it's 
missing.  This might be as simple as catching an exception thrown by 
newURI (if it throws such an exception) and retrying.

-myk

On Mar 12, 4:23 pm, Myk Melez <m...@mozilla.org> wrote:
> Eric...@gmail.com wrote:
> > I had actually implemented your method previously, but it seems that
> > if the data read() in does not contain "http://" it causes in error.
> > This was a reason i wanted to avoid converting the input to URI.  Is
> > there a way around this?
>
> If you know that strings without a scheme are http:// URLs, you could
> simply check for the presence of a scheme and prepend "http://" if it's
> missing.  This might be as simple as catching an exception thrown by
> newURI (if it throws such an exception) and retrying.
>
> -myk

I actually implemented a prependHTTP() functions as well ;D.  But
there is a slight problem with this because it is possible that a URL/
domain may use HTTPS instead of HTTP and I needed the entire URL to
match.  Is there a way (a function/API) to find out what the scheme is
for a domain (URL)? (Sorry if im misusing the terms, not quite
familiar with them).

Thanks so much
Eric

EricL84@gmail.com wrote:
> Is there a way (a function/API) to find out what the scheme is
> for a domain (URL)? (Sorry if im misusing the terms, not quite
> familiar with them).

No, as any given domain could have resources addressed by multiple 
schemes.  For example, the following URLs are all valid completions of 
the "URL" example.com/foo:

   http://example.com/foo
   https://example.com/foo
   ftp://example.com/foo
   irc://example.com/foo

But you might be able to sniff out a scheme by sending HEAD requests for 
each possible scheme in turn until you get a positive response.

-myk

Myk Melez wrote:
> EricL84@gmail.com wrote:
>> Is there a way (a function/API) to find out what the scheme is
>> for a domain (URL)? (Sorry if im misusing the terms, not quite
>> familiar with them).
> 
> No, as any given domain could have resources addressed by multiple
> schemes.  For example, the following URLs are all valid completions of
> the "URL" example.com/foo:
> 
>   http://example.com/foo
>   https://example.com/foo
>   ftp://example.com/foo
>   irc://example.com/foo
> 
> But you might be able to sniff out a scheme by sending HEAD requests for
> each possible scheme in turn until you get a positive response.
> 
> -myk

Uncontrolled sniffing around might be a bad thing, considering
especially privacy issues arising from it. Not to mention that some
grumpy sysadmin might consider this a portscan/breakin attempt. :p

There is however, nsIURIFixup which the location bar uses to do lookups...
http://mxr.mozilla.org/mozilla1.8/source/docshell/base/nsIURIFixup.idl
It will "guess" the correct scheme without actively sniffing... like
www.example.org => http, or ftp.example.org => ftp

Might worth having a look at it.

Nils

On Mar 12, 6:46 pm, Nils Maier <Maier...@web.de> wrote:
> Myk Melez wrote:
> > Eric...@gmail.com wrote:
> >> Is there a way (a function/API) to find out what the scheme is
> >> for a domain (URL)? (Sorry if im misusing the terms, not quite
> >> familiar with them).
>
> > No, as any given domain could have resources addressed by multiple
> > schemes.  For example, the following URLs are all valid completions of
> > the "URL" example.com/foo:
>
> >  http://example.com/foo
> >  https://example.com/foo
> >  ftp://example.com/foo
> >   irc://example.com/foo
>
> > But you might be able to sniff out a scheme by sending HEAD requests for
> > each possible scheme in turn until you get a positive response.
>
> > -myk
>
> Uncontrolled sniffing around might be a bad thing, considering
> especially privacy issues arising from it. Not to mention that some
> grumpy sysadmin might consider this a portscan/breakin attempt. :p
>
> There is however, nsIURIFixup which the location bar uses to do lookups...http://mxr.mozilla.org/mozilla1.8/source/docshell/base/nsIURIFixup.idl
> It will "guess" the correct scheme without actively sniffing... likewww.example.org=> http, or ftp.example.org => ftp
>
> Might worth having a look at it.
>
> Nils

Thanks for the tip on nsIURIFixup, this seems safer than prepending
http:// "manually".
However, im having trouble with a particular case of using
nsIURIFixup.  When I pass a domain to URIFixup, it prepends http://.
This website first goes to the http:// URL and then is redirected to a
httpS:// URL.  I am using the pageshow event and upon this event
firing, the final URL in the location bar is the httpS:// URL.  Is
there a way to find the final (redirected?) protocol and URL from a
domain?

Thanks