FAQ.xml

<faq xmlns:r="http://www.r-project.org">
<q>
I put my SVG files on the Web in compress form (i.e. .svgz),
but browsers don't seem to be able to view them but want the 
viewer to save the file.
<a>
Your web server needs to tell the requester that the file
is compressed SVG. It does this by returning the correct
Content-Type in the header of the HTTP response.
You need to tell your web server about these files.
Add 

<programlisting>
AddType image/svg+xml .svg .svgz
AddEncoding x-gzip .svgz
</programlisting>

to the &lt;VirtualHost&gt; stanza in your httpd.conf file.
(See <ulink url="http://httpd.apache.org/docs/1.3/mod/mod_mime.html"/>.)

Alternatively, you can add it to an .htaccess within a directory to
have it apply to it and all sub-directories.  That directory must be
configured in the server to allow .htaccess, i.e. the server has to
know to read the .htaccess file.
Note that the server must return a Content-Encoding of
x-gzip and not gzip for Firefox to understand the type correctly.
Opera understands both forms.
</a>
</q>

<q>
I've included the AddType and AddEncoding directives in the Apache
configuration. However, things still don't work.
<a>
Make certain to clear your cache. Your browser is still
probably 
I use 
<r:code>
library(RCurl)
x = getURLContent(u, .opts = list(verbose = TRUE), binary = TRUE)
</r:code>
to look at the header of the response to see what is happening.
You can also use the Live HTTP Headers extension for Firefox.
</a>
</q>

<q>
I can read .svgz files from the Web but not locally.
<a>
It is not clear that Firefox has support for this yet.
Opera does.
</a>
</q>


<q>
Tooltips. How do I get these to work for different browsers?

<a>
Within a path, for Opera, specify a title node as a child of path with the text of the tooltip.
For Firefox, put a xlink:title attribute on the path.
For Webkit (Safari and Google Chrome), enclose the path element within an
a element with a xlink:title attribute.

<p>
Firefox and WebKit seem to want to have the CSS inlined within the document
rather than referenced via a xml-stylesheet processing instruction.
That works for Opera.
</p>

<p>
It is critical that the processing instruction identifying an external CSS 
document be before the SVG root node. Otherwise, the CSS content will not
be used in any browser other than Opera (i.e. not in Safari, Chrome or Firefox).
</p>

<para>
We can refer to a CSS with a relative file name,
a full path name,
file:///Users/duncan/Rpackages/SVGAnnotation/CSS/RSVGPlot.css
or
file://localhost/Users/duncan/Rpackages/SVGAnnotation/CSS/RSVGPlot.css
</para>
</a>
</q>
</faq>