Can commands in a BUTTON be spread over multiple lines for readability?

[jhayes-apl]

I am trying to create a screen that controls a power supply (via the TEMPLATE protocol). The user will fill in the voltages and currents (via TEXTFIELDs). There will be a button that sends the commands to set up the power supply. I can put all the commands on a very long line. To make it easier to read, is it possible to spread commands over multiple lines in the screen file? I tried some experiments in this screen:

SCREEN AUTO AUTO 1.0

HORIZONTALBOX
  BUTTON 'Test1' 'api.cmd("POWER VOLTAGE_SET with CHANNEL 3, VOLTAGE 4.0"); api.cmd("POWER VOLTAGE_SET with CHANNEL 4, VOLTAGE 5.0")'
  BUTTON 'Test2' "api.cmd('POWER VOLTAGE_SET with CHANNEL 3, VOLTAGE 4.0'); api.cmd('POWER VOLTAGE_SET with CHANNEL 4, VOLTAGE 5.0')"
  BUTTON 'Test3' "api.cmd('POWER VOLTAGE_SET with CHANNEL 3, VOLTAGE 4.0');
api.cmd('POWER VOLTAGE_SET with CHANNEL 4, VOLTAGE 5.0')"
  BUTTON 'Test3a' "api.cmd('POWER VOLTAGE_SET with CHANNEL 3, VOLTAGE 4.0');" +
"api.cmd('POWER VOLTAGE_SET with CHANNEL 4, VOLTAGE 5.0')"
  BUTTON 'Test3b' "api.cmd('POWER VOLTAGE_SET with CHANNEL 3, VOLTAGE 4.0');" + \
"api.cmd('POWER VOLTAGE_SET with CHANNEL 4, VOLTAGE 5.0')"
  BUTTON 'Test4' "api.cmd('POWER VOLTAGE_SET with CHANNEL 3, VOLTAGE 4.0');\
api.cmd('POWER VOLTAGE_SET with CHANNEL 4, VOLTAGE 5.0')"
END

Here are the results:

• Test1: works, but one long line
• Test2: also works same using different quotes
• Test3 error: Syntax error ... literal not terminated before end of script
• Test3a: no errors, but second command is not sent
• Test3b: no errors, but second command is not sent
• Test4: error: Syntax error ... literal not terminated before end of script

Any suggestions?
I am using COSMOS 5.0.4 on Linux.

[ryanmelt]

The way this works in SCREEN definitions has changed in releases since 5.0.4. I still think it needs to be a single line though. @jmthomas Can you take a look?

[jmthomas]

Unfortunately due to our current parsing it has to be all on one line. I'll mark this as an enhancement.

[jhayes-apl]

I have no clue how this stuff works, but I will throw out an idea anyway. Can the screen include/require some javascript code? So, my_screen.txt might have:

REQUIRE my_helpers.js   # includes my_helper_function1, etc.
...
BUTTON 'Test1' 'my_helper_function1()'

This adds REQUIRE to your parser, but the parser wouldn't have to handle multi-line commands.

[jhayes-apl]

I have noticed that BUTTONs with more than one command issues the commands in a random order each time the button is clicked. Maybe this is intentional. If not, I could raise it as a separate issue.