9 Replies Latest reply on Jan 10, 2011 8:11 AM by Jeff Goldberg

Dynamically resizing iframe for embedded view via trusted authentication

. jgoldberg Jan 6, 2011 9:02 AM

That subject was a real mouthful!

We're using trusted authentication to embed views in an iframe in our portal.

The problem is that different views have different heights, so a hard-coded iframe height doesn't always look good (it ends up with unnecessary scrollbars).

I've got some javascript that has the parent page check the height of the iframe contents and resize the frame automatically. However, that javascript doesn't work when the contents of the iframe is on a different domain (or different port), which is the case since it's hitting the reporting server instead of the portal server.

I have been struggling to come up with an alternative.

Has anyone dealt with this issue before? Is there any way to ask the Tableau server the height of a particular view?

Thanks for any help,

Jeff

1. Re: Dynamically resizing iframe for embedded view via trusted authentication

James Baker Jan 6, 2011 9:35 AM (in response to . jgoldberg)

I suppose one way to get around cross-domain would be to just store a list mapping views to sizes. A maintenance pain to be sure...

There isn't any mechanism to ask the inner iframe right now. I think it would be possible for us to build a way for newer browsers to do so, using the HTML5ish "postMessage" functionality... but it takes some nasty hacks to do that in older browsers.
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2. Re: Dynamically resizing iframe for embedded view via trusted authentication

. jgoldberg Jan 6, 2011 11:11 AM (in response to . jgoldberg)
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3. Re: Dynamically resizing iframe for embedded view via trusted authentication

. jgoldberg Jan 6, 2011 11:25 AM (in response to . jgoldberg)

In my previous comment, I meant to say:

* * *
So instead of it being at

http://serverlocation/

It's at

http://serverlocation/tableau
* * *

Sorry, I had put it in brackets and it got edited out.

Also, one additional note... The reason I'm not able to handle this cleanly with a reverse proxy right now is because the Tableau server uses some absolute links.

So if I proxy

https://myserver/tableau1

to the Tableau server, it will partially work, but all absolute links end up breaking. (Images, some css, etc.)
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4. Re: Dynamically resizing iframe for embedded view via trusted authentication

. jgoldberg Jan 6, 2011 11:45 AM (in response to . jgoldberg)

Argh. There was a second piece of text in brackets that got edited out of my comment.

I had meant to ask:

* * *

Alternatively, is there a way to set a BASE tag in the head of the Tableau server?

* * *
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5. Re: Dynamically resizing iframe for embedded view via trusted authentication

James Baker Jan 6, 2011 12:24 PM (in response to . jgoldberg)

Uh, I believe you can add a directory to your "gateway.host" config variable. Don't quote me on that one, though, I can't remember whether that's supported or not.

And I thought we had customers running reverse proxies. At least I thought we had a policy of avoiding absolute links for that reason. (That is, absolute links that we generate whole, rather than simply modifying the protocol to/from https.) I wouldn't mind some specific examples of those images/css absolute links.
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6. Re: Dynamically resizing iframe for embedded view via trusted authentication

. jgoldberg Jan 6, 2011 1:03 PM (in response to . jgoldberg)

I said absolute links, but that's not true. Sorry to add confusion. (And sorry about slandering Tableau!)

What I mean is non-relative links, such as:

Since all those references have a "/" in front, the browser looks at the top of the domain.
So when I try to reverse proxy the site
https://myportal/tab1
to
https://mytabserver/

All those above links end up looking at the top level of
https://myportal/
And the reverse proxy fails to pick them up.

I'm definitely NOT an expert on proxy servers, so I admit I may be making foolish mistakes.

As to the first part of your comment, I tried adjusting the gateway.host (and the gateway.public.host) config setting, but it didn't seem to impact the url of the tableau server. It's possible I'm not using it correctly. If I wanted my server to be at https://mytabserver/tab1, what would the setting be?

Thanks so much for your help with this issue. I really appreciate it!

Jeff
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7. Re: Dynamically resizing iframe for embedded view via trusted authentication

. jgoldberg Jan 6, 2011 1:20 PM (in response to . jgoldberg)

Once again, the html tags were edited out of my comment. Sorry.

Examples of non-relative links are:
<link href="/stylesheets/base_packaged.css" media="screen" rel="stylesheet" type="text/css">
<script src="/javascripts/base_packaged.js" type="text/javascript">
<img align="left" alt="Tableau Server Home" border="0" id="logo" src="/images/server-logo.gif">
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8. Re: Dynamically resizing iframe for embedded view via trusted authentication

James Baker Jan 6, 2011 5:41 PM (in response to . jgoldberg)

Oops. I went and did some more checking and we definitely don't support hosting server in a subdirectory URL. Ignore what I said about gateway.host for that purpose. Sorry - I understand that it's a common request, though.

You can proxy one hostname to another hostname, but not to a subdirectory. I'm not a proxy expert myself, but I feel like there should be some way to proxy-and-transform in the way you want.
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9. Re: Dynamically resizing iframe for embedded view via trusted authentication

Jeff Goldberg Jan 10, 2011 8:11 AM (in response to . jgoldberg)

Is there any way to "hack" the html code that is coming out of the Tableau server by altering files or something in the installation?
One solution would be if I could add a "base" html tag to every page's header that allows me to treat it like it's in a subdirectory even though it's not.
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