How to trigger Bokeh actions from the Electron menu?

Question

I want to connect a Bokeh Application with Electron. The Electron window already shows the localhost:5006 of the bokeh application written in Python 3. Now I want to use the native user menu of electron to fire some actions of the Bokeh application. Is there any way to do this?

Answer 1

I have used some workarounds to achieve that in this project. Concretely I send signals to the iframe to run some js event and trigger python methods. In the future I hope bokeh will permit some RPC calls. The key files to get the functionality:

1. I load bokeh on an iframe in order to control the whole app from electron.

2. I send the signal to the iframe with this method.

   document.getElementById('bokeh_iframe').contentWindow.postMessage({
       "signal": "call-python-promise",
       "message_data": message
   } , '*');  // to index.html, the click on the button is run there as well
   

   One call example here. You can place those calls in the electron menu items (in the ipc renderer side).

   var call_params = {
       'object': 'bokeh.loader',
       'method': 'init_bokeh',
       'args': {
           'ts_state': $('body').data('ts_state'),
       }
   }
   tools.call_promise(call_params).then((result) => {
       self.run_on_ready();
   });
   

3. This object creates the machinery to trigger callbacks from js. A small bokeh form constructed with a button, a input text and a plot.

4. Here I fill the dummy text object to select the method to call (object and method). Then I trigger the python method (callback associated to the button) with button.click()
5. The object and method are received and computed in the python side. Finally, the bokeh method returns the answer to electron with the reversed process as I have exposed here.

As you can see this is quite cumbersome. If you find a better way to do it let me know. Some way to call python methods will be created in the future and all of this will be simpler.

Note: You may need to check when bokeh is loaded to redirect electron. Check this question and answer