Dialogflow Tutorial: Back Functionality in Chatbot using Python + Django | by Pragnakalp Techlabs

Now it’s time to create webhook URL for webhook.

To do that, copy the following code in your /Back_Function/Back_Function/urls.py file.

from django.urls import path
from myapp import views
urlpatterns = [
# define a route for home
path('home/', views.home, name='home'),
path('webhook/', views.webhook, name='webhook')
]

Building fulfillment responses from webhook

Copy below code in the Back_Function/myapp/views.py file.

from django.shortcuts import render
from django.http import HttpResponse, JsonResponse
from django.views.decorators.csrf import csrf_exempt
import json
from df_response_lib import *
# define home function
def home(request):
return HttpResponse('Hello World!')
@csrf_exempt
def webhook(request):
ff_response = fulfillment_response()
# build a request object of the qebhook request
req = json.loads(request.body)
# get action from json
action = req.get('queryResult').get('action')
# Django responses from webhook
# response for the Stage_1 intent
if action == "S_1":
Text_response = "You are in Stage 1."
# response for the Stage_2 intent
elif action == "S_2":
Text_response = "You are in Stage 2."
# response for the Stage_3 intent
elif action == "S_3":
Text_response = "You are in Stage 3."
# response for the Stage_4 intent
elif action == "S_4":
Text_response = "You are in Stage 4."
storage = []
context = []
# loop over the all the context 
mess = req.get('queryResult').get("outputContexts")
for m in mess:
name = m.get('name')
# save the parameter value of 'back' context which is our saved last responses
if name[-len("back"):] == "back":
stored = m.get("parameters").get("parameter")
for k in stored:
storage.append(k)
else:
# contexts of the current stage
context.append(m)
# when request for back is arise, get the last response from the storage which was saved in the parameter of the back context and remove the currernt response from the data.
if action == "back":
temp = storage[-2]
ff_context = temp[1]
ff_text = temp[0]
storage.pop(len(storage)-1)
else:
ff_text = ff_response.fulfillment_text(Text_response)
new_data = [ff_text, context]
storage.append(new_data)
# output context from the webhook for back functionality    
contexts = [['back', 100, 'parameter': storage]]
# get session name from fulfilment reqest
session = req.get("session")
# set the output context in the webhook response
ff_out_context  = ff_response.output_contexts(session, contexts)
# Also activate the contexts of the last response
if action == "back":
for i in range(len(ff_context)):
ff_out_context.get('output_contexts').append(ff_context[i])
# set webhook response for the requested action        
reply = ff_response.main_response(fulfillment_text = ff_text, output_contexts = ff_out_context)
# webhook response
return JsonResponse(reply, safe = False)

In this, we are using our Dialogflow Response Library which you can clone from our github repo.

Now our django project is ready. Let’s execute below command to run server.

python manage.py runserver

In our previous step we created a webhook with URL /webhook but it is your local application and it is not accessible publicly. We need a URL which can be accessed by Dialogflow, so to do that we need a tool to call webhook from the local server. For that purpose we can use a web tunneling tool NGROK. You can download it from here.

After installing NGROK, run below command in the new terminal. Our app is running on port 8000.

ngrok http 8000

You should get output look like below.

ALLOWED_HOSTS = [ '47901fda.ngrok.io', '127.0.0.1' ]