Oh that was easy to fix, just convert it to json:
in test.py :
body= json.dumps(your_object)#str(response))
However, I don't know if this is the best implementation. Suppose the
node.js application makes requests to different methods in python (in
fact the user selects operations in the UI). What would be a nice, (if
possible, elegant) implementation for that using AMQP?
I see some alternatives, but I'm not sure if they are good for this:
pass the method name inside the body of the request
having a channel.basic_consume(callback_method_1, queue='queue_1')
for each method in python.
having an "exchange" for each method
What are your thoughts?
On Apr 27, 5:35 pm, Cassio Melo <[email protected]> wrote:
> Thanks Micheil, Bika,
>
> I succeed in making a simple string transfer using AMQP:
>
> test.py
> -------
> import pika
>
> connection = pika.BlockingConnection(pika.ConnectionParameters(
> host='localhost'))
> channel = connection.channel()
>
> channel.queue_declare(queue='task_queue', durable=True)
>
> print ' [*] Waiting for messages. To exit press CTRL+C'
>
> def callback(ch, method, props, body):
> print " [x] Received %r" % (body,)
> response = body + " MODIFIED"
> #response = get_a_concept()
> print " [x] Done"
> ch.basic_publish(exchange='',
> routing_key=props.reply_to,
> properties=pika.BasicProperties(correlation_id =
> \
>
> props.correlation_id),
> body=str(response))
> ch.basic_ack(delivery_tag = method.delivery_tag)
>
> channel.basic_qos(prefetch_count=1)
> channel.basic_consume(callback,
> queue='task_queue')
>
> channel.start_consuming()
>
> ------
> app.js
> ------
>
> var connection = amqp.createConnection({ host: 'localhost' });
>
> connection.addListener('ready', function() {
>
> var exchange = connection.exchange('', {
> 'type' : 'direct',
> durable : false
> }, function() {
>
> var queue = connection.queue('incoming', {
> durable : false,
> exclusive : true }, function() {
> queue.subscribe(function(msg) {
> console.log("received message: ");
> console.log(msg.data.toString());
> });
>
> });
>
> exchange.publish('task_queue', "it works!", {
> 'replyTo' : 'incoming'
> });
> });
>
> });
>
> ---
>
> Still, I'm not sure if this is the best implementation, I'm not even
> using queue.bind() method here. The problem arises when I try to pass
> a complex object (json or even a simple array). Changing this line
>
> body= (["a","b","c"])#str(response)) causes the following error:
>
> Traceback (most recent call last):
> File "test.py", line 56, in <module>
> channel.start_consuming()
> File "/Library/Python/2.7/site-packages/pika/adapters/
> blocking_connection.py", line 293, in start_consuming
> (...)
> File "/Library/Python/2.7/site-packages/pika/simplebuffer.py", line
> 62, in write
> self.buf.write(data)
> TypeError: must be string or read-only character buffer, not list
>
> But that I will check in some python list. If someone has any comment
> don't hesitate!
>
> Cheers,
> Cassio
>
> On Apr 27, 3:39 pm, Micheil Smith <[email protected]> wrote:
>
>
>
>
>
>
>
> > I wouldn't be using redis for this, definitely would use either zmq,
> > rabbitmq,
> > or thrift. Purely because it's kinda hard to scale redis' pub/sub stuff, and
> > can be a SPOF.
>
> > – Micheil
>
> > On 26/04/2012, at 5:08 PM, Bika wrote:
>
> > > I've read about a similar problem here [1], they basically write from
> > > node to Redis, and use Redis' pub/sub to broadcast the changes to django.
>
> > > [1]:http://lincolnloop.com/blog/2012/apr/23/ginger-tech-stack/
>
> > > 2012. április 25., szerda 15:15:35 UTC+2 időpontban Cassio Melo a
> > > következőt írta:
> > > I'm beginning with websockets and I'm confused with the number
> > > libraries and configuration options. I just want to setup a project
> > > where a node.js server calls a method in python/django and when the
> > > last has finished, it transfers the result back to the node.js
> > > server.
>
> > > I'm not sure which is the best way of doing that (supposing the method
> > > to be executed in django takes some time to finish). I see two
> > > possibilities:
>
> > > - node.js send async http requests to django server
> > > - node.js communicates with django using AMQP
>
> > > Can you give your view about it?
>
> > > --
> > > Job Board:http://jobs.nodejs.org/
> > > Posting
> > > guidelines:https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines
> > > You received this message because you are subscribed to the Google
> > > Groups "nodejs" group.
> > > To post to this group, send email to [email protected]
> > > To unsubscribe from this group, send email to
> > > [email protected]
> > > For more options, visit this group at
> > >http://groups.google.com/group/nodejs?hl=en?hl=en
--
Job Board: http://jobs.nodejs.org/
Posting guidelines:
https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines
You received this message because you are subscribed to the Google
Groups "nodejs" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/nodejs?hl=en?hl=en
