Revision as of 18:12, 9 November 2007

Proposal to convert gbrowse_details to an AJAX request handler

A temporary page to describe a low-impact change to existing code to provide a built-in ajax handler for Gbrowse

Examples

• A balloon hover with contents generated using an AJAX call to gbrowse_details and the params callback shown below

• A sticky balloon with contents generated from gbrowse-details (via an <iframe> element) and the default callback shown below.

Changes to gbrowse_details

• A new CGI parameter to invoke the AJAX-handling behavior

my $rmt   = param('remote');

• A response is triggered after the feature(s) are defined but before PrintTop is called.

if (defined $rmt) {
  print header,start_html;
  print remote_content($rmt,$features[0]);
  print end_html;
  exit 0;
}

• The remote_content subroutine will get the text or coderef. It will return the text or execute the callback with user-defined arguments

# do something for popup balloons                                                                                                                                             
sub remote_content {
  my $key = shift; # the key for the text or code-ref in the gbrowse config file                                                                                              
  my $feat = shift;
  my $contents = $CONFIG->config->code_setting('TOOLTIPS',$key) or die "$key is empty";                                                                                                                 
  my $coderef = (ref $contents||'') eq 'CODE';
  return $contents unless $coderef;  
  # paranoia?                                                                                                                                                                 
  die "Error: $key is not a CODE-REF" if ref $contents && !$coderef;
  # args are user-defined                                                                                                                                                     
  my %args = (feature => $feat) if $feat;
  for my $arg (param()) {
    my @vals = param($arg);
    my $val  = @vals > 1 ? \@vals : $vals[0];
    $args{$arg} = $val;
  }
  return $contents->(\%args);
}

Changes To Configuration File

• A new section [TOOLTIPS] that has all the named text sections or callbacks you need to access through gbrowse_details
  • NOTE: This section must be placed at the end of the [GENERAL] section.

• The balloon configuration (unchanged). The 375px max-width balloon is used in the examples above

• The [ORF] contig stanza used to generate the images above. The relevant section is highlighted

Changes to Bio::Graphics::Browser

• Minimal changes to balloons code. Width option introduced to allow custom width constraints. Setting the iframe width should hopefully make the contents stay inside the balloon boundaries.