Load dynamic image based on filename in database?

[rexbutler]

Quick question: in can one insert an image into an iReport whose filename is determined dynamically via a database value just like one can display a dynamic database string?

Thanks,

Rex

 

[jmurray]

If the pics are stored locally on the report server then you can reference them directly, but if they're on (say) a remote web server you'll need to pass the pic url to an external image rendering tool (for example cricket grapher can render network utilisation graphs on the fly given the correct URI, and the png output files can be embedded in the report).

[jmurray]

The attached pdf is a sample that contains dynamically generated cricket graphs.

Page 1 is just a title page.  Page 2 contains three images that are dynamically created by an external rendering tool.  Page 3 contains 4 subreports that generate jasperreport graphs from data for specific timeframes.

The following query from the main report provides base textual data for the left hand side of page 2 and the URI strings that are used for the weekly, monthly and yearly cricket graphs on the right hand side of page 2.
 

<queryString><![CDATA[select DISTINCT a.*, b.tail_fqhostname     , 'http://public.nms.det.nsw.edu.au/weathermap/proxy.php?'    || 'url=http://cricket.nms.det.nsw.edu.au/?type=png;target='    || substr(rrdpath,14,length(rrdpath)-17)    || ';inst=0;dslist=ifHCInOctets%2CifHCOutOctets;range=604800;rand=763' as weekly     , 'http://public.nms.det.nsw.edu.au/weathermap/proxy.php?'    || 'url=http://cricket.nms.det.nsw.edu.au/?type=png;target='    || substr(rrdpath,14,length(rrdpath)-17)    || ';inst=0;dslist=ifHCInOctets%2CifHCOutOctets;range=2592000;rand=763' as monthly     , 'http://public.nms.det.nsw.edu.au/weathermap/proxy.php?'    || 'url=http://cricket.nms.det.nsw.edu.au/?type=png;target='    || substr(rrdpath,14,length(rrdpath)-17)    || ';inst=0;dslist=ifHCInOctets%2CifHCOutOctets;range=31536000;rand=763' as yearly  from planned_bw a, rrd_paths_path b, planned_bw_consumption c where a.HOSTNAME || '.net.det.nsw.edu.au'= c.hostname   and A.HOSTNAME || '.net.det.nsw.edu.au'= b.tail_fqhostname   and a.hostname='cabr01'   and (       c.consumption_key = $P!{consumption_key1}     or c.consumption_key = $P!{consumption_key2} or c.consumption_key = $P!{consumption_key3} or c.consumption_key = $P!{consumption_key4}       )   order by A.REGION, A.SITE_NAME]]>[/code]

The URI strings contain a URL for the wrapper cgi script, a rendering URL for the cricket grapher, the path to the interface to be graphed and the parameters required by the cricket grapher to render the correct counters for the right period (in this case one week):

wrapper cgi: 'http://public.nms.my.hidden.web.site/weathermap/proxy.php?'render URL:  'url=http://cricket.nms.my.hidden.web.site/?type=png;target='target path:  substr(rrdpath,14,length(rrdpath)-17)parameters:  ';inst=0;dslist=ifHCInOctets%2CifHCOutOctets;range=604800;rand=763' as weekly[/code]

The assembled URI might look something like this:

http://public.nms.my.hidden.web.site/weathermap/proxy.php?url=http://cricket.nms.my.hidden.web.site/?type=png;target=/routers/offices/swsy/cabr01/gigabitethernet0_0;inst=0;dslist=ifHCInOctets%2CifHCOutOctets;range=604800;rand=763

The URI is then used in an image element like this:

<image hyperlinkType="Reference"> <reportElement key="image-1" x="395" y="10" width="385" height="160"/> <imageExpression class="java.lang.String"><![CDATA[$F{WEEKLY}]]></imageExpression> <hyperlinkReferenceExpression><![CDATA[$F{WEEKLY}]]></hyperlinkReferenceExpression></image>[/code]

Hope this helps if you were considering using an external rendering tool.