Re: Display Images on .bob using DBWR

["Kasemir, Kay via Tech-talk" <tech-talk at aps.anl.gov>]

See https://github.com/ornl-epics/dbwr/blob/main/Readme.md and follow the suggestion under “Client URLs” about making all files available via web links.

Instead of 

...view.jsp?display=file:/path/to/display.bob

you want to go with 

...view.jsp?display=http://my_control_system_host/displays/path/to/display.bob

That way, you’ll end up with image links like

 http:/my_control_system_host/LCPC/Symbol/VR Steam Trap.png

that allow the client to fetch the file and not

 file:/opt/tomcat/webapps/dbwr/LCPC/Symbol/VR Steam Trap.png

where the client tries to get a file that only exists on the web server file system

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Vishnu Patel via Tech-talk <tech-talk at aps.anl.gov>
Date: Friday, August 7, 2026 at 5:49 AM
To: EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: [EXTERNAL] Display Images on .bob using DBWR

This Message Is From an External Sender

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Dear Sir,

      I have configured the Phoebus Display Builder Web Runtime(DBWR) to display .bob files through a web browser.

After completing the Tomcat and DBWR configuration, I am able to successfully open and display the .bob panel in the client machine web browser. However, the pictures/symbols used in the .bob file are not displayed.

The browser shows an error while trying to load these image/symbol files. It appears that DBWR is referring to the image files using a local file path on the server, which cannot be accessed by the client browser.

The browser console error is shown below. 

--------------------

Loading 'file:/opt/tomcat/webapps/dbwr/LCPC/CompressorLocal.bob' with {}

dbwr.js?V=1786090605:560 New rule for w147 'background_color'

dbwr.js?V=1786090605:134 Connecting PVs

dbwr.js?V=1786090605:134 Disconnected

pvws.js?V=1786090605:30 Opening ws://10.20.120.45:8080/pvws/pv

pvws.js?V=1786090605:40 Connected to ws://10.20.120.45:8080/pvws/pv

dbwr.js?V=1786090605:134 Initialize Widgets

picture.js?V=1786090605:16 Cannot load picture from file:/opt/tomcat/webapps/dbwr/LCPC/Symbol/VR Steam Trap.png because web browser cannot access files on server.

DisplayBuilderWebRuntime.widget_init_methods.picture @ picture.js?V=1786090605:16

6picture.js?V=1786090605:16 Cannot load picture from file:/opt/tomcat/webapps/dbwr/LCPC/Symbol/Radiological Protection Screw1.png because web browser cannot access files on server.

DisplayBuilderWebRuntime.widget_init_methods.picture @ picture.js?V=1786090605:16

view.jsp?display=file:/opt/tomcat/webapps/dbwr/LCPC/CompressorLocal.bob:1 Not allowed to load local resource: file://opt/tomcat/webapps/dbwr/LCPC/Symbol/VR%20Steam%20Trap.png

---------------

The DBWR/Tomcat logs on the server is 

$tail -f /opt/tomcat/logs/catalina.out

07-Aug-2026 13:46:46.276 INFO [http-nio-8080-exec-3] dbwr.rules.RuleSupport.handleRule PolygonWidget ID w147 rule:

<rule name="Rule" out_exp="false" prop_id="background_color">

<exp bool_exp="pv0==1">

<value>

<color blue="0" green="255" red="0">

</color>

</value>

</exp>

<exp bool_exp="pv0==0">

<value>

<color blue="0" green="85" red="0">

</color>

</value>

</exp>

<pv_name>LCPC_CRYO_COMP_C_RUN</pv_name>

</rule>

.. turned into ..

{

  // Rule 'Rule'

  let rule2 = new WidgetRule('w147', 'background_color', ['LCPC_CRYO_COMP_C_RUN']);

  rule2.eval = function()

  {

    let pv0 = this.value['LCPC_CRYO_COMP_C_RUN'];

    let pvStr0 = this.valueStr['LCPC_CRYO_COMP_C_RUN'];

    if (pv0==1) return '#00FF00';

    if (pv0==0) return '#005500';

    return '#005500';

  }

  rule2.update = set_svg_background_color

}

07-Aug-2026 13:46:46.290 INFO [http-nio-8080-exec-3] dbwr.servlets.DisplayCache.getOrCreate Cache created file:/opt/tomcat/webapps/dbwr/LCPC/CompressorLocal.bob {}: Load time 23ms

$tail -f /opt/tomcat/logs/localhost_access_log*.txt

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/view.jsp?display=file:/opt/tomcat/webapps/dbwr/LCPC/CompressorLocal.bob HTTP/1.1" 200 6255

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/widgets/actionbutton.css?V=1786090605 HTTP/1.1" 200 688

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/css/widgets.css?V=1786090605 HTTP/1.1" 200 2595

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/widgets/databrowser.css?V=1786090605 HTTP/1.1" 200 140

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/widgets/boolbutton.css?V=1786090605 HTTP/1.1" 200 101

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/widgets/tabs.css?V=1786090605 HTTP/1.1" 200 1087

10.20.61.51 - - [07/Aug/2026:13:46:45 +0530] "GET /dbwr/widgets/navtabs.css?V=1786090605 HTTP/1.1" 200 1304

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/tank.css?V=1786090605 HTTP/1.1" 200 250

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/textupdate.css?V=1786090605 HTTP/1.1" 200 127

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/group.css?V=1786090605 HTTP/1.1" 200 130

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/led.css?V=1786090605 HTTP/1.1" 200 161

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/textentry.css?V=1786090605 HTTP/1.1" 200 147

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/combo.css?V=1786090605 HTTP/1.1" 200 35

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /pvws/js/pvws.js?V=1786090605 HTTP/1.1" 200 5486

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/scrollbar.js?V=1786090605 HTTP/1.1" 200 1152

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/js/dbwr.js?V=1786090605 HTTP/1.1" 200 22169

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/clock.js?V=1786090605 HTTP/1.1" 200 901

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/xyplot.js?V=1786090605 HTTP/1.1" 200 6185

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/symbol.js?V=1786090605 HTTP/1.1" 200 1065

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/bytemonitor.js?V=1786090605 HTTP/1.1" 200 1361

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/actionbutton.js?V=1786090605 HTTP/1.1" 200 3596

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/databrowser.js?V=1786090605 HTTP/1.1" 200 6373

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/boolbutton.js?V=1786090605 HTTP/1.1" 200 933

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/navtabs.js?V=1786090605 HTTP/1.1" 200 3356

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/tabs.js?V=1786090605 HTTP/1.1" 200 1783

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/led.js?V=1786090605 HTTP/1.1" 200 2963

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/checkbox.js?V=1786090605 HTTP/1.1" 200 1090

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/radio.js?V=1786090605 HTTP/1.1" 200 2473

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/tank.js?V=1786090605 HTTP/1.1" 200 821

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/textupdate.js?V=1786090605 HTTP/1.1" 200 4970

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/slider.js?V=1786090605 HTTP/1.1" 200 999

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/combo.js?V=1786090605 HTTP/1.1" 200 1779

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/textentry.js?V=1786090605 HTTP/1.1" 200 2940

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/picture.js?V=1786090605 HTTP/1.1" 200 755

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/spinner.js?V=1786090605 HTTP/1.1" 200 484

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/image.js?V=1786090605 HTTP/1.1" 200 18304

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/progressbar.js?V=1786090605 HTTP/1.1" 200 541

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/boolmonitor.js?V=1786090605 HTTP/1.1" 200 829

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/multistatemonitor.js?V=1786090605 HTTP/1.1" 200 258

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/widgets/polyline.js?V=1786090605 HTTP/1.1" 200 209

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /dbwr/screen?display=file%3A%2Fopt%2Ftomcat%2Fwebapps%2Fdbwr%2FLCPC%2FCompressorLocal.bob&macros=%7B%7D&cache=true HTTP/1.1" 200 47376

10.20.61.51 - - [07/Aug/2026:13:46:46 +0530] "GET /pvws/pv HTTP/1.1" 101 -

10.20.1.222 - - [07/Aug/2026:13:59:20 +0530] "GET /pvws/pv HTTP/1.1" 101 -

Could you please advise how this issue can be resolved? Specifically, I would appreciate your guidance on 

How to configure DBWR to access image/symbol file used in the .bob.

Your guidance on the recommended configuration would be highly appreciated.

With regards

Vishnu