firebaseaio

Firebase-aio

A simple async python wrapper for the Firebase API.

Installation

pip install git+https://github.com/09ghostrider/firebase-aio

Getting Started

Python Version

Firebase-aio was written for python 3 and will not work correctly with python 2.

Add firebase-aio to your application

For use with only user based authentication we can create the following configuration:

import firebaseaio
config = {
  "apiKey": "apiKey",
  "authDomain": "projectId.firebaseapp.com",
  "databaseURL": "https://databaseName.firebaseio.com",
  "storageBucket": "projectId.appspot.com"
}
firebase = firebaseaio.initialize_app(config)

We can optionally add a service account credential to our configuration that will allow our server to authenticate with Firebase as an admin and disregard any security rules.

import firebaseaio
config = {
  "apiKey": "apiKey",
  "authDomain": "projectId.firebaseapp.com",
  "databaseURL": "https://databaseName.firebaseio.com",
  "storageBucket": "projectId.appspot.com",
  "serviceAccount": "path/to/serviceAccountCredentials.json"
}
firebase = firebaseaio.initialize_app(config)

Adding a service account will authenticate as an admin by default for all database queries, check out the Authentication documentation for how to authenticate users.

Use Services

A firebase-aio app can only use Firebase database services.

firebase.database() - Check out the Database documentation for further details.

Database

You can build paths to your data by using the child() method.

db = firebase.database()
db.child("users").child("Morty")

Save Data

push

To save data with a unique, auto-generated, timestamp-based key, use the push() method.

data = {"name": "Mortimer 'Morty' Smith"}
await db.child("users").push(data)

set

To create your own keys use the set() method. The key in the example below is "Morty".

data = {"name": "Mortimer 'Morty' Smith"}
await db.child("users").child("Morty").set(data)

update

To update data for an existing entry use the update() method.

await db.child("users").child("Morty").update({"name": "Mortiest Morty"})

remove

To delete data for an existing entry use the remove() method.

await db.child("users").child("Morty").remove()

multi-location updates

You can also perform multi-location updates with the update() method.

data = {
    "users/Morty/": {
        "name": "Mortimer 'Morty' Smith"
    },
    "users/Rick/": {
        "name": "Rick Sanchez"
    }
}
await db.update(data)

To perform multi-location writes to new locations we can use the generate_key() method.

data = {
    "users/"+ref.generate_key(): {
        "name": "Mortimer 'Morty' Smith"
    },
    "users/"+ref.generate_key(): {
        "name": "Rick Sanchez"
    }
}
await db.update(data)

Retrieve Data

val

Queries return a PyreResponse object. Calling val() on these objects returns the query data.

users = await db.child("users").get()
print(users.val()) # {"Morty": {"name": "Mortimer 'Morty' Smith"}, "Rick": {"name": "Rick Sanchez"}}

key

Calling key() returns the key for the query data.

user = await db.child("users").get()
print(user.key()) # users

each

Returns a list of objects on each of which you can call val() and key().

all_users = await db.child("users").get()
for user in all_users.each():
    print(user.key()) # Morty
    print(user.val()) # {name": "Mortimer 'Morty' Smith"}

get

To return data from a path simply call the get() method.

all_users = await db.child("users").get()

Conditional Requests

It's possible to do conditional sets and removes by using the conditional_set() and conitional_remove() methods respectively. You can read more about conditional requests in Firebase here.

To use these methods, you first get the ETag of a particular path by using the get_etag() method. You can then use that tag in your conditional request.

etag = await db.child("users").child("Morty").get_etag()
data = {"name": "Mortimer 'Morty' Smith"}
await db.child("users").child("Morty").conditional_set(data, etag)

If the passed ETag does not match the ETag of the path in the database, the data will not be written, and both conditional request methods will return a single key-value pair with the new ETag to use of the following form:

{ "ETag": "8KnE63B6HiKp67Wf3HQrXanujSM=" }

Here's an example of checking whether or not a conditional removal was successful:

etag = await db.child("users").child("Morty").get_etag()
response = await db.child("users").child("Morty").conditional_remove(etag)
if "ETag" in response:
    etag = response["ETag"] # our ETag was out-of-date
else:
    print("We removed the data successfully!")

shallow

To return just the keys at a particular path use the shallow() method.

all_user_ids = await db.child("users").shallow().get()

Note: shallow() can not be used in conjunction with any complex queries.

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': 'firebaseaio', "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.

You can also add a stream_id to help you identify a stream if you have multiple running:

my_stream = db.child("posts").stream(stream_handler, stream_id="new_posts")

close the stream

my_stream.close()

Complex Queries

Queries can be built by chaining multiple query parameters together.

users_by_name = await db.child("users").order_by_child("name").limit_to_first(3).get()

This query will return the first three users ordered by name.

order_by_child

We begin any complex query with order_by_child().

users_by_name = await db.child("users").order_by_child("name").get()

This query will return users ordered by name.

equal_to

Return data with a specific value.

users_by_score = await db.child("users").order_by_child("score").equal_to(10).get()

This query will return users with a score of 10.

start_at and end_at

Specify a range in your data.

users_by_score = await db.child("users").order_by_child("score").start_at(3).end_at(10).get()

This query returns users ordered by score and with a score between 3 and 10.

limit_to_first and limit_to_last

Limits data returned.

users_by_score = await db.child("users").order_by_child("score").limit_to_first(5).get()

This query returns the first five users ordered by score.

order_by_key

When using order_by_key() to sort your data, data is returned in ascending order by key.

users_by_key = await db.child("users").order_by_key().get()

order_by_value

When using order_by_value(), children are ordered by their value.

users_by_value = await db.child("users").order_by_value().get()

Helper Methods

generate_key

db.generate_key() is an implementation of Firebase's key generation algorithm. See multi-location updates for a potential use case.

sort

Sometimes we might want to sort our data multiple times. For example, we might want to retrieve all articles written between a certain date then sort those articles based on the number of likes. Currently the REST API only allows us to sort our data once, so the sort() method bridges this gap.

articles = await db.child("articles").order_by_child("date").start_at(startDate).end_at(endDate).get()
articles_by_likes = db.sort(articles, "likes")

Common Errors

Index not defined

Indexing is not enabled for the database reference.