root/galaxy-central/display_applications/gbrowse/gbrowse_gff.xml

<display id="gbrowse_gff" version="1.0.0" name="display at GBrowse">
    <!-- Load links from file: one line to one link -->
    <dynamic_links from_file="tool-data/shared/gbrowse/gbrowse_build_sites.txt" skip_startswith="#" id="0" name="0">
        <!-- Define parameters by column from file, allow splitting on builds -->
        <dynamic_param name="site_id" value="0"/>
        <dynamic_param name="gbrowse_link" value="1"/>
        <dynamic_param name="builds" value="2" split="True" separator="," />
        <!-- Filter out some of the links based upon matching site_id to a Galaxy application configuration parameter and by dataset dbkey -->
        <filter>${site_id in $APP.config.gbrowse_display_sites}</filter>
        <filter>${dataset.dbkey in $builds}</filter>
        <!-- We define url and params as normal, but values defined in dynamic_param are available by specified name -->
        <url>${gbrowse_link}/?${position}eurl=${gff_file.qp}</url>
        <param type="data" name="gff_file" url="galaxy_${DATASET_HASH}.gff" />
        <param type="template" name="position" strip="True" >
#set chrom, start, end = $gff_file.datatype.get_estimated_display_viewport( $gff_file )
#if $chrom is not None:
#if $chrom.startswith( 'chr' ):
    #set $chrom = $chrom[3:]
#end if
q=${chrom}:${start}..${end}&amp;
#end if
        </param>
    </dynamic_links>
</display>