NikDev IoT Client (Python)

Python API for accessing the NikDev IoT Server

This package is serving as an API client for accessing the NikDev IoT Server, and simplify uploading data to the server.

Installation

Using pip:

pip install nikdev-iot

From source:

python setup.py install

Using the API

Before using the API you need to create an account and a device to connect against.

Finding ID and Keys

In order to connect to the server you need a Device ID and an API Key. Both the Device ID and API Key are of a UUID structure: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

The Device ID is found on the first view when you open your device on the Server GUI, and the API Key can be found under the section API Keys under the same device. If you don't have an API Key you can create one.

Importing and initializing

To import the API, use the following:

from nikdev_iot import Api, PushException, GetException

The PushException and GetException can be good to import to catch eventual errors when sending or receiving data.

To initialize the API class, there's 2 options. Either you can pass a dict with configuration values, or you can create it from entering the credentials. The second option is handy if you want to use the default configuration.

# Method 1: initialization with a dict.
api = Api({
    'deviceId': '<Device ID>',
    'apiKey': '<API Key>'
})

# Method 2: initialization with credentials.
api = Api.from_credentials('<Device ID>', '<API Key>')

Test connection

Not implemented yet.

Storing data

In order to add and store data to the API, you must pass the data as key-value pairs.

api.add_value('<Field ID 1>', '<Value>')
api.add_value('<Field ID 2>', '<Value>')

Trying to add 2 values with the same Field ID will overwrite the previous value.

After entering all values you'd like to store you must commit them. Committing values will lock them, just like a commit in git, and is prepared to be pushed.

api.add_value(...)
api.commit()

The terminology is on purpose made to mirror git commands as much as possible, since it's a simple way to get a quick start on the API (assumed you know some of the git commands).

Uploading data

After you've committed your values it's time to uoload them. Uploading is done by calling push(). This will try to upload any committed values to the server. If there's unpushed committed values they will be uploaded as well.

api.add_value(...)
api.commit()
api.push()

It's possible to run both commit and push in one function call by using commit_and_push().

api.add_value(...)
api.commit_and_push()

Normally you don't get any response from either commit() or push(). However, if there's an error when uploading the values push() will throw an PushException. This can be done for a number of reasons, but the important cases are:

• You entered wrong Device ID or API Key
• Your API Key doesn't have write access (this can easily be fixed from the Server GUI)
• The server messed up.
• The connection timed out.

The last two reasons are categorized as "Bad Luck" and you can try again to upload your data. However, if there's anything wrong with the Device ID or API Key (entered wrong or doesn't have access) your committed values will be thrown away.

if you want to catch these exceptions, just wrap the push command with a try/exception clause and catch PushException:

try:
    # Try to push the values to the server
    api.push()
except PushException as exception:
    if exception.retained_data:
        pass
        # The data is still intact and can be re-pushed
    else:
        pass
        # The data is no more.
    pass

Full example

# Importing the API
from nikdev_iot import Api, PushException

# Initialize the api from credentials
api = Api.from_credentials('<Device ID>', '<API Key>')

# Add values to be uploaded
api.add_value('<Field ID 1>', '<Value>')
api.add_value('<Field ID 2>', '<Value>')
# Commit the values to "lock" them, meaning you can add
# new values of the same Field ID without overwriting the previous.
api.commit()

# Adding am additional value for Field ID 1
api.add_value('<Field ID 1>', '<Another Value>')
# Commit that value as well
api.commit()

try:
    # Try to push the values to the server
    api.push()
except PushException as exception:
    # Check if the data was retained
    if exception.retained_data:
        # If so, sleep for a while and try to push it again.
        import time; time.sleep(2)
        # This time it's without try catch, if we fail here the program crashes.
        api.push()
    pass

Fetching data

Not implemented yet.