Question

I have a finite state machine (django-fsm) which allows an object to go from a source state into one of several target states. I can add all the actions in a dictionary like:

ACTIONS { 'button_1': action1,
          'button_2': action2,
           ...
}

This translates in a form with a submit button for each state.

  {% for n,m in object.get_available_current_state_transitions %}
      <input type="submit" class="btn" value="{{ n|get_action|capfirst }}"
             name="button_{{n}}" />
  {%endfor%}

  <input type="submit" class="btn primary" value="Save">
  <a class="btn" onclick="javascript:history.go(-1)">Cancel</a>

This usually results in more than 3 buttons.

Clicking a button results in a specific action, defined in my case in the model class.

Now, I know I can get the clicked button in the request.POST dictionary, but this would result in a cascade if like:

  if 'button_1' in request.POST:
      action_1()
  elif 'button_2' in request.POST:
      ...

Is there any way to get the button pressed separately (ideally from the request object) in a variable so I can have something like

ACTIONS[clicked_button_name](...)

? In other words, is there any way to obtain the clicked button outside the POST dictionary?

PS: I’ve looked other replies on the “multiple buttons” question, but all offer request.POST as answer.

Answer 1

If all of the actions and strings are already in your view, why don’t you just iterate over that actions dict?

for key, value in ACTIONS.items():
    if key in request.POST:
        value()

Just make your button names very unlikely to be used as a regular form field name.

---

A few alternatives: use javascript to handle the submission and have it set a single form field such as “action”.

Use more unique keys and filter through request.POST.keys() with a regex pattern or string comparison.

action = [x for x in request.POST.keys() if 'FAIRLY_UNIQUE_BUTTON_PREFIX' in x]

if action:
    ACTIONS[action]()