JSON examples

Create a plain HTTP with data format set to JSON to turn on automatic (de-)serialization of incoming/returned JSON messages.

Accessing JSON request

By default, a JSON message is converted to a Python dictionary.

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from zato.server.service import Service

class MyService(Service):
    def handle(self):
        self.logger.info(type(self.request.payload))
        self.logger.info(self.request.payload)
        self.logger.info(self.request.payload['mydata']['cust']['id'])

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$ curl localhost:11223/example -d '{"mydata":{"cust":{"id":1,"name":"Jack Brown"}}}'
$

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INFO - <type 'dict'>
INFO - {u'mydata': {u'cust': {u'id': 1L, u'name': u'Jack Brown'}}}
INFO - 1

Converting JSON to Bunch

It’s usually convenient to convert JSON to a Bunch instance and use dotted notation to reference elements of the request.

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# bunch
from bunch import bunchify

# Zato
from zato.server.service import Service

class MyService(Service):
    def handle(self):
        mydata = bunchify(self.request.payload['mydata'])
        self.logger.info(mydata.cust.id)
        self.logger.info(mydata.cust.name)

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$ curl localhost:11223/example -d '{"mydata":{"cust":{"id":1,"name":"Jack Brown"}}}'
$

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INFO - 1
INFO - Jack Brown

Creating responses

Assign a string representation of JSON to self.response.payload - it doesn’t matter how it’s produced as long as it results in a string, hence all the examples below achieve the same.

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from zato.server.service import Service

class MyService(Service):
    def handle(self):
        self.response.payload = """{"customer": {"products": [{"type": "AMZN",
          "id": 1}, {"type": "KZUA", "id": 2}], "id": 123, "name": "John Brown"}}"""

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# anyjson
from anyjson import dumps

# Zato
from zato.server.service import Service

class MyService(Service):
    def handle(self):

        response = {
          'customer': {
            'id':123,
            'name':'John Brown',
            'products': [
                {'id':1, 'type':'AMZN'},
                {'id':2, 'type':'KZUA'}
        ]}}

        self.response.payload = dumps(response)

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# anyjson
from anyjson import dumps

# bunch
from bunch import Bunch

# Zato
from zato.server.service import Service

class MyService(Service):
    def handle(self):
        response = Bunch()
        response.customer = Bunch()
        response.customer.id = 123
        response.customer.name = 'John Brown'
        response.customer.products = []
        response.customer.products.append({'id':1, 'type':'AMZN'})
        response.customer.products.append({'id':2, 'type':'KZUA'})

        self.response.payload = dumps(response)

Output below reformatted for clarity.

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$ curl localhost:11223/example -d '{}'
{"customer":
  {"products": [
    {"type": "AMZN", "id": 1},
    {"type": "KZUA", "id": 2}],
 "id": 123,
 "name": "John Brown"}}
$

Invoking a JSON service using GET

Create a plain HTTP outgoing connection to a remote JSON service, such as this one provided by Yahoo! and invoke it through self.outgoing.plain_http.

The response is a string that can be turned into a Python dictionary or a Bunch instance, like in the examples below.

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# anyjson
from anyjson import loads

# Zato
from zato.server.service import Service

class MyService(Service):
    def handle(self):
        response = self.outgoing.plain_http.get('Yahoo! Finance').conn.get(self.cid)
        data = loads(response.text)

        for item in data['list']['resources']:
            name = item['resource']['fields']['name']
            price = item['resource']['fields']['price']

            self.logger.info('{} {}'.format(name, price))

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# anyjson
from anyjson import loads

# bunch
from bunch import bunchify

# Zato
from zato.server.service import Service

class MyService(Service):
    def handle(self):
        response = self.outgoing.plain_http.get('Yahoo! Finance').conn.get(self.cid)
        data = bunchify(loads(response.text))

        for item in data.list.resources:
            name = item.resource.fields.name
            price = item.resource.fields.price

            self.logger.info('{} {}'.format(name, price))

Invoking a JSON service using POST

Create a plain HTTP outgoing connection to a remote JSON service and invoke it through self.outgoing.plain_http passing the input JSON document as a string to the .post method.

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# anyjson
from anyjson import dumps

# Zato
from zato.server.service import Service

class MyService(Service):
    def handle(self):

        cust_profile = self.outgoing.plain_http.get('CRM Customer Profile')

        request = dumps({'cust_id':1, 'name':'Foo Bar'})
        response = cust_profile.conn.post(self.cid, request)

        self.logger.info(response.text)