Finding out if a HTML page in a foreign domain exists before youallow navigation to it

[Stevo]

Does anyone know of a way to check if a html file exists in a different
domain so that you can know in advance whether going there would result
in a 404? I believe Ajax would allow that in the same domain, but
wouldn't in a different domain. The page I might go to is totally out of
my control, so I can't do anything that side. I'm expecting this won't
be possible, but figured I'd ask.

[Randy Webb]

Re: Finding out if a HTML page in a foreign domain exists beforeyou allow navigation to it

Stevo said the following on 2/22/2008 11:37 AM:

Does anyone know of a way to check if a html file exists in a different
domain so that you can know in advance whether going there would result
in a 404? I believe Ajax would allow that in the same domain, but
wouldn't in a different domain. The page I might go to is totally out of
my control, so I can't do anything that side. I'm expecting this won't
be possible, but figured I'd ask.

No. Not on an internet site anyway. I could dream up a way to do it
running locally though.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javas cript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Stevo]

Re: Finding out if a HTML page in a foreign domain exists beforeyou allow navigation to it

Randy Webb wrote:

Stevo said the following on 2/22/2008 11:37 AM:

>Does anyone know of a way to check if a html file exists in a
>different domain so that you can know in advance whether going there
>would result in a 404? I believe Ajax would allow that in the same
>domain, but wouldn't in a different domain. The page I might go to is
>totally out of my control, so I can't do anything that side. I'm
>expecting this won't be possible, but figured I'd ask.

>
No. Not on an internet site anyway. I could dream up a way to do it
running locally though.

Thanks, figured as much.

[John Nagle]

Re: Finding out if a HTML page in a foreign domain exists beforeyou allow navigation to it

Stevo wrote:

Does anyone know of a way to check if a html file exists in a different
domain so that you can know in advance whether going there would result
in a 404? I believe Ajax would allow that in the same domain, but
wouldn't in a different domain. The page I might go to is totally out of
my control, so I can't do anything that side. I'm expecting this won't
be possible, but figured I'd ask.

If it's a page on a server you control, you could have a link-checking
process on the server which checked your pages and disabled broken links.
That's entirely on the server side.

If it's on a client you control, you could write a Greasemonkey script
to check links on each page as it is loaded. But the overhead would be
high.

What are you trying to do?

John Nagle
SiteTruth

[adamcbrz@gmail.com]

Re: Finding out if a HTML page in a foreign domain exists before youallow navigation to it

On Feb 23, 10:32 pm, John Nagle <na...@animats. comwrote:

Stevo wrote:

Does anyone know of a way to check if a html file exists in a different
domain so that you can know in advance whether going there would result
in a 404? I believe Ajax would allow that in the same domain, but
wouldn't in a different domain. The page I might go to is totally out of
my control, so I can't do anything that side. I'm expecting this won't
be possible, but figured I'd ask.

>
    If it's a page on a server you control, you could have a link-checking
process on the server which checked your pages and disabled broken links.
That's entirely on the server side.
>
    If it's on a client you control, you could write a Greasemonkey script
to check links on each page as it is loaded.  But the overhead would be
high.
>
    What are you trying to do?
>
                                        John Nagle
                                        SiteTruth

this can be accoplished with Ajax, PHP, & Curl. Curl is an extention
for php. With it you can retieve alot a information on a site/page
including the status.

Hope that helps!
Adam

[Stevo]

Re: Finding out if a HTML page in a foreign domain exists beforeyou allow navigation to it

John Nagle wrote:

Stevo wrote:

>The page I might go to is totally out of my control

If it's a page on a server you control, you could have a link-checking
process on the server which checked your pages and disabled broken links.
That's entirely on the server side.

Sadly it's not :(

If it's on a client you control, you could write a Greasemonkey script
to check links on each page as it is loaded. But the overhead would be
high.
>
What are you trying to do?

I was asked if I could provide some JavaScript that could check whether
a regular link to a different site would result in a 404. I said that I
was 99% sure it couldn't be done but I'd ask around.

[Stevo]

Re: Finding out if a HTML page in a foreign domain exists beforeyou allow navigation to it

adamcbrz@gmail. com wrote:

On Feb 23, 10:32 pm, John Nagle <na...@animats. comwrote:

>Stevo wrote:

>>Does anyone know of a way to check if a html file exists in a different
>>domain so that you can know in advance whether going there would result
>>in a 404? I believe Ajax would allow that in the same domain, but
>>wouldn't in a different domain. The page I might go to is totally out of
>>my control, so I can't do anything that side. I'm expecting this won't
>>be possible, but figured I'd ask.

this can be accoplished with Ajax, PHP, & Curl. Curl is an extention
for php. With it you can retieve alot a information on a site/page
including the status.
Hope that helps!
Adam

Unfortunately I would only have Javascript available for this.