How to detect changes in firebase child with python?

Question

I have some troubles with this application. What I need is that If I detect a change in the database (FIREBASE) particularly in \'sala\' and \'ventilacion\' nodes the functi

Answer 1

Question: How to detect changes in firebase child

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Note: All Examples use Public Access

1. Setup Example Data and verify it's readable.
   This hase to be done once!

   temperature_c = 30
   data = {'date':time.strftime('%Y-%m-%d'), 
           'time':time.strftime('%H:%M:%S'), 
           'temperature':temperature_c}
   db.child('public').child('Device_1').set(data)
   
   response = db.child('public').child('Device_1').get()
   print(response.val())
   

2. Create First Script doing Updates:

   for t in [25, 26, 27, 28, 29, 30, 31, 32, 33, 35]:
       temperature_c = t
       data = {'date':time.strftime('%Y-%m-%d'), 
               'time':time.strftime('%H:%M:%S'), 
               'temperature':temperature_c}
       db.child('public').child('Device_1').update(data)
       time.sleep(60)
   

3. Create Second Script with Stream Handler

   def stream_handler(message):
       print('event={m[event]}; path={m[path]}; data={m[data]}'
           .format(m=message))
   
   my_stream =db.child('public').child('Device_1').stream(stream_handler)
   
   # Run Stream Handler forever
   while True:
       data = input("[{}] Type exit to disconnect: ".format('?'))
       if data.strip().lower() == 'exit':
           print('Stop Stream Handler')
           if my_stream: my_stream.close()
           break
   

4. Run Stream Handler Script:

   Response Output from def stream_handler after startup (Initial Data):

   event="put"; path=/;  data={'Device_1': {'temperature': 30, 'time': '13:34:24', 'date': '2017-07-20'}}
   

5. Run Updater Script:

6. Watch Output from Stream Handler Script

   Response Output from def stream_handler after First Update Data:

   event=patch; path=/Device_1;  data={'temperature': 25, 'time': '13:49:12'}
   

Tested with Python: 3.4.2

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Pyrebase
streaming

You can listen to live changes to your data with the stream() method.

def stream_handler(message):
    print(message["event"]) # put
    print(message["path"]) # /-K7yGTTEp7O549EzTYtI
    print(message["data"]) # {'title': 'Pyrebase', "body": "etc..."}

my_stream = db.child("posts").stream(stream_handler)

You should at least handle put and patch events. Refer to "Streaming from the REST API" for details.