BitcartCC SDK Events System¶
Introduction¶
To be able to listen for incoming payments, transactions, new blocks or more, you should use events system.
In SDK, each event may have one handler.
One handler may handle multiple events at once
Using event system requires wallet.
Event handler signature is the following:
def handler(event, arg1, arg2):
pass # process event
Where event is the only required argument everywhere.
Depending on the event being handled, it may provide additional arguments. All arguments must be named exactly as event is specifying.
If using event system from APIManager, then additional required argument instance is passed:
def handler(instance, event, arg1, arg2):
pass # process event
Also, async handlers are supported too, like so:
async def handler(event, arg1, arg2):
pass # process event, you can await here
Registering event handlers¶
To register an event handler, use on decorator:
@coin.on("event")
def handler(event, arg1, arg2):
pass
You can also register a handler for multiple events, then you should mark all arguments, except for event and instance (if provided) optional, like so:
@coin.on(["event1", "event2"])
def handler(event, arg1=None, arg2=None, arg3=None):
pass # event argument can be used to get what event is currently being processed
Or you can use add_event_handler method instead:
def handler(event, arg1, arg2):
pass
coin.add_event_handler("event", handler)
They work identically.
Events list¶
new_transaction¶
Called when a new transaction on this wallet has appeared
Additional data:
- tx (str): tx hash of this transaction
new_payment¶
Called when status of payment request has changed. (See get_request/add_request)
Additional data:
- address (str): address related to this payment request
- status (int): new status code
- status_str (str): string version of new status code
Listening for updates¶
To receive updates, you should use one of the available event delivery methods: polling or webhook
Polling¶
Polling is good for quick testing, but not very good for production.
In this method SDK calls get_updates daemon method constantly, processing any new updates received.
To use it, run:
coin.poll_updates()
It will start an infinite loop.
Webhook¶
Webhook is a bit harder to set up sometimes, but works better.
Instead of constantly calling daemon method to get updates, daemon will send updates when they are available.
To use it, run:
coin.start_webhook()
It will start an aiohttp server, by default at port 6000.
With default configuration daemon will be notified of the webhook automatically.
Currently only one webhook per wallet is supported.
If you have some existing routes in aiohttp, you can integrate your aiohttp server and webhooks.
coin.configure_webhook()
coin.webhook_app.add_post(...) # coin.webhook_app is a configured aiohttp app instance
That way you can configure the app the needed way.
If you are running webhook at a different port or host, you will need to notify daemon of it manually:
coin.configure_webhook(autoconfigure=False)
coin.server.configure_notifications("http://some.host:port")
Manual updates processing¶
If you need complete control over updates delivery, you can pass updates to coin’s method directly:
coin.process_updates(updates_list)
Where updates_list is a list of dictionaries.
Each dictionary must contain event key, and additional keys for data required for this event.
Processing updates for multiple wallets/currencies¶
If you need to process updates for multiple wallets/currencies, take a look at APIManager documentation