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You can also see how servicebar works here: https://github.com/Eugeny/ajenti/blob/dev/ajenti/plugins/services/main.py#L55
Then it's a much better idea to simply create a link/label and update it depending on service status. 
1. You should put that update inside on_page_load (see http://docs.ajenti.org/ref/ajenti.plugins.main.api... ) method, which is called each time when navigating to section.
2. from ajenti.plugins.services.api import ServiceMultiplexor
3. use ServiceMultiplexor.get().get_one('servicename').start/stop/restart/running (see http://docs.ajenti.org/ref/ajenti.plugins.services... ) to start/stop service with your custom buttons and get the service status.
If you need any help, you can write directly to e@ajenti.org or skype: john.pankov
Actually, DOM is rebuilt on each UI update, so it's not generally possible to invoke JS methods from Python without actually refreshing the UI. One thing you can do is to create a boolean property (show_dialog), which is checked in JS createDom().
However we have a special API which you can use to show messages: http://docs.ajenti.org/dev/notifications.html
Instead of "Something to see", use #{@properties.value}
this.properties (@properties) contains all values for properties which were defined with @p in Python and later set with, for example, self.find("textinfo").value
Take a look at Custom UI Controls article: http://docs.ajenti.org/dev/custom-controls.html
(you can use JS instead of CoffeeScript too)
Service bar picks service status directly from Services plugin. Depending on OS, your script must be compatible with Upstart (Debian-based) or SysV-init (Debian and RHEL).
As I guess you probably have written your script in SysV-init style, service status is detected by checking exitcode when calling /etc/init.d/xxx status.
Exitcode 0 means running, other codes mean stopped.
Click "auto refresh" button for this.
Looks like, unfortunately, Socket.IO (we use it) doesn't support IPv6 :(
https://github.com/LearnBoost/socket.io-client/issues/260
This is a remote-side bug (just fixed).