50 lines
1.8 KiB
ReStructuredText
50 lines
1.8 KiB
ReStructuredText
Connecting to RabbitMQ with Callback-Passing Style
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==================================================
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When you connect to RabbitMQ with an asynchronous adapter, you are writing event
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oriented code. The connection adapter will block on the IOLoop that is watching
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to see when pika should read data from and write data to RabbitMQ. Because you're
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now blocking on the IOLoop, you will receive callback notifications when specific
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events happen.
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Example Code
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------------
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In the example, there are three steps that take place:
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1. Setup the connection to RabbitMQ
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2. Start the IOLoop
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3. Once connected, the on_open method will be called by Pika with a handle to
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the connection. In this method, a new channel will be opened on the connection.
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4. Once the channel is opened, you can do your other actions, whether they be
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publishing messages, consuming messages or other RabbitMQ related activities.::
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import pika
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# Step #3
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def on_open(connection):
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connection.channel(on_channel_open)
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# Step #4
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def on_channel_open(channel):
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channel.basic_publish('exchange_name',
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'routing_key',
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'Test Message',
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pika.BasicProperties(content_type='text/plain',
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type='example'))
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# Step #1: Connect to RabbitMQ
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connection = pika.SelectConnection(on_open_callback=on_open)
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try:
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# Step #2 - Block on the IOLoop
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connection.ioloop.start()
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# Catch a Keyboard Interrupt to make sure that the connection is closed cleanly
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except KeyboardInterrupt:
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# Gracefully close the connection
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connection.close()
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# Start the IOLoop again so Pika can communicate, it will stop on its own when the connection is closed
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connection.ioloop.start()
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