Synnefo

# vim: ts=4 sts=4 et ai sw=4 fileencoding=utf-8

#

# Copyright © 2010 Greek Research and Technology Network

#

from xml.dom import minidom

from piston.emitters import Emitter, Mimer

class OSXMLEmitter(Emitter):

    """

    Custom XML Emitter that handles some special stuff needed by the API.

    Shamelessly stolen^Wborrowed code (sans Piston integration) by OpenStack's

    Nova project and hence:

    Copyright 2010 United States Government as represented by the

    Administrator of the National Aeronautics and Space Administration.

    Copyright 2010 OpenStack LLC.

    and licensed under the Apache License, Version 2.0

    """

    _metadata = {

            "server": [ "id", "imageRef", "name", "flavorRef", "hostId",

                        "status", "progress", "progress", "description", "created", "updated" ],

            'ip': ['addr'],

            'ip6': ['addr'],

            'meta': ['key'],

            "flavor": [ "id", "name", "ram", "disk", "cpu" ],

            "image": [ "id", "name", "updated", "created", "status",

                       "serverId", "progress", "size", "description"],

            "group": [ "id", "name", "server_id"],

        }

    def _to_xml_node(self, doc, nodename, data):

        """Recursive method to convert data members to XML nodes."""

        result = doc.createElement(nodename)

        if type(data) is list:

            if nodename.endswith('s'):

                singular = nodename[:-1]

            else:

                singular = 'item'

            for item in data:

                node = self._to_xml_node(doc, singular, item)

                result.appendChild(node)

        elif type(data) is dict:

            attrs = self._metadata.get(nodename, {})

            for k, v in data.items():

                if k in attrs:

                    #protect from case where unicode with ascii chars is casted to str

                    v = v.__class__ == str and v.decode("utf8") or unicode(v)

                    result.setAttribute(k, v)                    

                else:

                    node = self._to_xml_node(doc, k, v)

                    result.appendChild(node)

        else: # atom

            node = doc.createTextNode(str(data))

            result.appendChild(node)

        return result

    def render(self, request):

        data = self.construct()

        # We expect data to contain a single key which is the XML root.

        root_key = data.keys()[0]

        doc = minidom.Document()

        node = self._to_xml_node(doc, root_key, data[root_key])

        return node.toprettyxml(indent='    ')

Emitter.register('xml', OSXMLEmitter, 'application/xml')

Mimer.register(lambda *a: None, ('application/xml',))