How to trigger execution of arbitrary JavaScript code in browser from Bokeh Server?

From Bryan Van de Ven @bryevdv Mar 08 20:52

@Sklavit you will probably want to wait for bokeh/bokeh#5941

From description:

The API will be very similar to the existing on_change and js_on_change API used to register callbacks triggered by property changes.

As for my question on 2017-03-09, there are several way to trigger JS code from server:

• Define JS callback as

  some_model.callback = CustomJS(code="alert('hi!')")
  

  What is triggering callback is unclear

• Define JS callback as

  some_model.js_on_change = CustomJS(code="alert('hi!')")
  

  js_on_change is present only for few models

• Code injection in DataTable's

  TableColumn(..., formatter=HTMLTemplateFormatter(template="<% alert('hi!') %>"))
  

My current solution Create hidden holder

    callback_holder = PreText(text='', css_classes=['hidden'])
    callback = CustomJS(args={}, code='alert(cb_obj.text);')
    callback_holder.js_on_change('text', callback)

And then in other part of application:

    def update():
        callback_holder.text = 'data for JS code'
    curdoc().add_next_tick_callback(update)

You might want to use templates. An example of how to use templates for bokeh-server app can be found here: https://github.com/bokeh/bokeh/tree/master/examples/app/crossfilter