Set MIME type for PNG and SVG images.

doc/frontend.rst

@@ -182,7 +182,7 @@ automatically handle downloads of these files. Note that if the backend
 generates additional files in the job directory which should not be downloaded, the :meth:`~saliwebfrontend.allow_file_download` method can be overridden to
 control which files the end user is allowed to download. Note also that if
 some files are not text files, the :meth:`~saliwebfrontend.get_file_mime_type`
-method should also be overridden to specify the MIME type.
+method may also need to be overridden to specify the MIME type.
 
 The example below assumes the backend generates a log file ``log`` and a
 single output file, ``output.pdb``, and allows the user to download these files

doc/modules/frontend.rst

@@ -237,9 +237,10 @@ the web frontend.
       :meth:`~saliwebfrontend.download_results_file`) this
       method is called to get the correct
       `MIME type <http://en.wikipedia.org/wiki/Internet_media_type>`_
-      for the file. By default, it always returns 'text/plain'. You may need
-      to override this, for example, if some of your results files are tar
-      files ('application/x-tar') or PNG images ('image/png').
+      for the file. By default, it handles PNG and SVG images, and for
+      all other files returns 'text/plain'. You may need to override this,
+      for example, if some of your results files are tar
+      files ('application/x-tar') or other types of image.
 
    .. method:: get_submit_parameter_help()
 

perl/saliweb/frontend.pm

@@ -377,6 +377,7 @@ use CGI;
 use Error qw(:try);
 use MIME::Lite;
 use Fcntl ':flock';
+use File::Basename;
 
 our $web_server = 'modbase.compbio.ucsf.edu';
 
@@ -1547,7 +1548,15 @@ sub allow_file_download {
 }
 
 sub get_file_mime_type {
-    return 'text/plain';
+    my ($self, $file) = @_;
+    my ($dir, $name, $ext) = fileparse($file, qr/\.[^.]*/);
+    if ($ext eq '.png') {
+        return 'image/png';
+    } elsif ($ext eq '.svg') {
+        return 'image/svg+xml';
+    } else {
+        return 'text/plain';
+    }
 }
 
 sub _download_real_file {

test/frontend/results_page.pl

@@ -34,6 +34,11 @@
         is(saliweb::frontend::get_file_mime_type($cls, $file), 'text/plain',
            "check get_file_mime_type: $file");
     }
+    is(saliweb::frontend::get_file_mime_type($cls, "/abspath/foo.png"),
+       'image/png', "check get_file_mime_type: /abspath/foo.png");
+
+    is(saliweb::frontend::get_file_mime_type($cls, "/abspath/foo.svg"),
+       'image/svg+xml', "check get_file_mime_type: /abspath/foo.svg");
 }
 
 # Test download_real_file