URLs, files with extensions and browser helper applications

[awingnut]

I am having a problem getting helper applications (specifically Citrix) to run under OS X. They work under windows but not on a MAC. I need to better understand how this stuff works and maybe why a Mac browser is different. Helper application defintions include the mime type application/x-ica. Where does this come into play with respect to html tags? A browser will launch the application on OS X if I use IIS on the Citrix machine which has a link to an 'asp' file. Unfortunately, I cannot see the source for that 'asp' page but it must be doing something different that the browser understands (it obviously is telling the browser about the MIME type because the browser asks me if it can launch application/x-ica). It is that diffence that I need to understand.

Here are the details of what doesn't work:

I have a link on a page with the href:

http://myhost.mydomain.com/citrixapp.ica

What I expect to happen is for the browser to recognize the 'ica' file type and launch the citrix application. Instead the browser (any) simply displays the contents of the files in the borwser window as text. Shouldn't try to it download the file instead and ask the user to either save or open?

Can someone explain this behavior to me so I can modify my page to do the same thing the 'asp' page does? TIA.

 

[ggriffit]

have you tried Google which seems to have a lot of hits :

http://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=citrix+mac+browser

 

[awingnut]

Yes. I am convinced this is not really a Citrix issue but rather a browser and/or HTML problem. The crux of the problem is that the browsers display the file as text rather then downloading it. What do I need to do in my link to make it download rather then display?

<a href="

http://myhost.mydomain.com/citrixapp.ica">

Blah blah</a>

Why does this work for windows browsers and not Mac?

 

[ggriffit]

could be a mapping issue that the browser does not know what to do with the file when it gets it, in Windows you would need to check the IIS Mappings and then the local client MIME type config, not sure of the equiverlant of the latter in Mac's as I don't have one to hand.

 

[awingnut]

Thanks for the reply. And there's the rub. I don't know either. THe MIME type application/x-ica is defined as a helper but nothing happens.

 

[BillyRayPreachersSon]

In Netscape, I believe you can add in helpers for certain MIME types - does Safari (you are using Safari, I assume?) have such an option?

Hope this helps,
Dan

 

[awingnut]

That is what prompted this thread. Although defined, Netscape doesn't do anything. Safari does not have a way to add helper apps. However, if it would download the file, like it is supposed to, a simple double click on it would launch the app. As it stands now my users have to ctrl-click on the link and do a save-as to get the file.

 

[BillyRayPreachersSon]

Do you have access to change the MIME type?

 

[awingnut]

For Netscape, yes.

However, playing more I found this rather bizzare.

I installed IIS on the Citrix server. When I click on the link served by that server, the browser downloads and launches the app. Obviously, the browser can do it under the right circumstances. Although the link is an asp page there still must be something that the browser recognizes that is missing from my link. But what?

Why doesn't the browser download the page rather then display it as text? The contents of te downloaded page is irrlelvent at that point so it has to be something in the link. What causes the browser to download a file rather then just display it?

 

[BillyRayPreachersSon]

The MIME type sent by the server.

I should have said in my last post that i was referring to the server-side MIME type.

Dan

 

[awingnut]

Server side???? How do I set that???? What is the HTML tag and where does it go? Why isn't it needed for Windows browsers?

 

[BillyRayPreachersSon]

>> Server side????

Yes

>> How do I set that????

I don't know - it depends on the server you're using... You'd need to refer to your server's manual / help file.

>> What is the HTML tag and where does it go? Why isn't it needed for Windows browsers?

Now I think you're going down the wrong path. Having the HTML tag at the top isn't going to make the browser any more or less likely to render the page. I'm 99.9% sure it'll be server-side MIME types.

Hope this helps,
Dan

The HTML tag is used to tell a browser thas nothing to do with MIME types, or why

 

[awingnut]

Are you referring to the 'AddType' directive in Apache's 'httpd.conf' for example?

I hope not because that is already there for ica.

 

[BillyRayPreachersSon]

I believe it's something like that for Apache.

Instead of serving "ica" files as "application/x-ica", server them as whatever "html" files are served as. That should sort your problems out.

Hope this helps,
Dan

 

[awingnut]

Now you've confused me. I don't follow what you mean by serving them as HTML files. That seems like how they are behaving now which is given me the trouble. I've taken the question over to the Apache forum since it seems to be a server issue at this point. Thanks for getting me this far. I'll see if I need to come back.

 

[BillyRayPreachersSon]

All you need to do is see what MIME type ".html" files are being served as from Apache. For example, they may be "text/html" or something similar.

Then, put that MIME type as the type served for ".ica" files, instead of "application/x-ica".

I think that should be clear enough.

Let me know if it works,
Dan

 

[awingnut]

Bingo! I don't understand it but that was it. I owe you an adult beverage of your choice. Thanks.

 

[BillyRayPreachersSon]

Aah - I can explain what the change was - as far as my limited understand goes, at least (so this may not be 100% correct ;o)

Basically, the server sends a text string with each page it delivers to the browser, independent of the content of the page, which tells the browser the MIME type of that page, based upon the extension of that page.

For your setup, Apache was told to deliver ".ica" files as MIME type "application/x-ica".

When a browser receives a file from the server, it usually decides what to do with it based upon the MIME type specified by the server. If it doesn't understand the MIME type, it normally pops up a box asking you if you want to open, save, etc. If it does understand the MIME type, then it will normally perform a default action based upon that MIME type. Sometimes browsers will also take different action depending on known file extensions.

In the case of "application/x-ica", your browser didn't know what to do with it, and probably didn't know what ".ica" files were either, so prompted you to open, save, etc.

What you did was effectively tell the browser that ".ica" files were the same as plain old ".html" files, and so it chose to parse them as HTML files, instead of popping up the box.

I think that's right, anyway ;o)

Dan