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root / ncclient / transport / hello.py @ c35cebbf

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# Copyright 2009 Shikhar Bhushan
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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#    http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"All to do with NETCONF <hello> messages"
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from xml.etree import cElementTree as ET
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from ncclient.glue import Listener
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from ncclient.content import TreeBuilder, BASE_NS
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from ncclient.content import qualify as _
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from ncclient.content import unqualify as __
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class HelloHandler(Listener):
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    def __init__(self, init_cb, error_cb):
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        self._init_cb, self._error_cb = init_cb, error_cb
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    def __str__(self):
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        return 'HelloListener'
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    def callback(self, root, raw):
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        if __(root[0]) == 'hello':
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            try:
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                id, capabilities = parse(raw)
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            except Exception as e:
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                self._error_cb(e)
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            else:
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                self._init_cb(id, capabilities)
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    def errback(self, err):
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        self._error_cb(err)
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    @staticmethod
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    def build(capabilities, encoding='utf-8'):
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        "Given a list of capability URI's returns encoded <hello> message"
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        spec = {
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            'tag': _('hello', BASE_NS),
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            'children': [{
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                'tag': 'capabilities',
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                'children': # this is fun :-)
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                    [{ 'tag': 'capability', 'text': uri} for uri in capabilities]
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                }]
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            }
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        return TreeBuilder(spec).to_string(encoding)
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    @staticmethod
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    def parse(raw):
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        "Returns tuple of ('session-id', ['capability_uri', ...])"
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        sid, capabilities = 0, []
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        root = ET.fromstring(raw)
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        for child in root.getchildren():
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            if __(child.tag) == 'session-id':
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                sid = child.text
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            elif __(child.tag) == 'capabilities':
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                for cap in child.getiterator(_('capability', BASE_NS)):
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                    capabilities.append(cap.text)
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                # cisco doesn't namespace hello message
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                for cap in child.getiterator('capability'): 
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                    capabilities.append(cap.text)
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        return sid, capabilities