A set of paired examples showing the four interactions of a Thing
- Advertise and share a Feed of your own
- Follow someone else's feed
- Advertise a control of your own
- Attach and actuate someone else's control.
In each case there will be examples covering different ways of binding (by Lid, Pid or guid or by searching) and different ways of approaching data (e.g. via feed templates and callback parsed or just plain)
The plain template is just the empty ThingRunner template for you to fill in. The plain template background is another empty ThingRunner template for you to fill in - but this one runs in the background, allowing you to other things in the foreground (run a graphing package, for instance)
The basic share Creates a thing, a feed and their metadata in on_startup().
It uses its main() method to create a loop which shares the feed on a timer.
The basic share error Creates a thing, a feed and their metadata in
on_startup().
It uses its main() method to create a loop which shares the feed on a timer.
It demonstrates the use of the RetryingThingRunner and the on_exception() method.
RetryingThingRunner is a subclass of ThingRunner that automatically handles network errors and continues
to retry indefinitely. If you want to handle any other exceptions, you have to overload on_exception(), call
the superclass' method and then you have a place to handle any other (unhandled) exceptions that might occur
The basic follow Creates a thing and binds a callback_parsed method to receive the
data from the basic share thing. The shared feed data is extracted in the parsed
callback by using filter_by to search within the feed for values that match certain criteria.
NOTE Requires basic share to be running to work
The basic follow catchall
Creates a thing and binds a catchall and a catchall_parsed
method to receive the data from the basic share thing as before.
In on_startup() the client.catchall_feeddata method is called. This routes any recent shares
have either been queued for this Thing while it has been offline or shares for feeds with no explicit callback.
NOTE Requires basic share to be running to work
The basic follow recent Creates a thing and binds a callback_parsed
method to receive the data from the basic share thing as before.
In on_startup() the remote_point.get_recent() method is called. This returns however many recent shares
there are saved by the remote feed. At the moment, there isn't a way to have the recent data parsed, so we
have to use hard-coded keys in __callback_recent()
NOTE Requires basic share to be running to work
The basic follow restore Creates a thing and binds a callback_parsed
method to receive the data from the basic share thing as before.
In on_startup() the client.list_connections() method is called. This returns a list of all the subscriptions
this thing might have had in the past and re-binds them. Effectively restoring state.
callback by using filter_by to search within the feed for values that match certain criteria.
NOTE Requires basic share to be running to work
The basic follow subscription Creates a thing and then,
in on_startup(), the client.register_callback_subscription() method is called.
This registers a callback that is called when a subscription is made on your behalf (probably in the UI, but it
could be you following something in another thread).
The subscription callback gets called with either a RemoteFeed or a RemoteControl object which can be further
inspected to see what callback to bind to its feeddata.
NOTE Requires basic share to be running to work
The basic follow database Creates a thing and then,
in on_startup(), the client.register_callback_subscription() method is called.
This registers a callback that is called when a subscription is made on your behalf (probably in the UI, but it
could be you following something in another thread).
When the subscription callback is called, the feed is added to a database table of feeds and when the data arrives
in the feeddata callback, the data received is added to another database table to hold feed values.
This example uses the popular SQLAlchemy ORM abstraction and SQLite3. Owing to the nature of SQLite's session thread
handling, this example uses a python queue to communicate between the callback functions
(which are called in the agent's thread) and the main thread which holds the session object.
NOTE Requires basic share to be running to work
The basic offer Creates a thing, a control and their metadata in on_startup().
When it creates the control it binds a callback_parsed method to receive the
data from the basic attach thing. The control request data is extracted
in the parsed callback by using filter_by to search within the feed for values that match certain criteria.
The basic attach Creates a thing and attaches to the control in
basic offer, in on_startup().
It uses its main() method to create a loop which calls ask() on the control.
NOTE Requires basic offer to be running to work
The basic attach tell Creates a thing and attaches to the control in
basic offer, in on_startup().
It uses its main() method to create a loop which calls tell() on the control. tell() requires the offerer
of the control to confirm whether it has done it. In this example we deliberately fail to see this confirmation
working.
NOTE Requires basic offer to be running to work
search owned, Creates a Thing in on_startup() and then uses
client.search(search_text, scope=SearchScope.LOCAL_OWN) to get a list of things it owns.
It then binds to the first thing's feed.
NOTE Requires basic share to be running to work
search global, Creates a Thing in on_startup() and then uses
client.search() to get a list of things that match the criteria.
It then binds to the first thing's feed.
NOTE Requires basic share to be running to work
All examples require the Iotic Agent
pip3 install py-IoticAgent
The database example requires