OsmApi.py

   1 #-*- coding: utf-8 -*-
   2
   3 ###########################################################################
   4 ##                                                                       ##
   5 ## Copyrights Etienne Chové <chove@crans.org> 2009                       ##
   6 ##                                                                       ##
   7 ## This program is free software: you can redistribute it and/or modify  ##
   8 ## it under the terms of the GNU General Public License as published by  ##
   9 ## the Free Software Foundation, either version 3 of the License, or     ##
  10 ## (at your option) any later version.                                   ##
  11 ##                                                                       ##
  12 ## This program is distributed in the hope that it will be useful,       ##
  13 ## but WITHOUT ANY WARRANTY; without even the implied warranty of        ##
  14 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         ##
  15 ## GNU General Public License for more details.                          ##
  16 ##                                                                       ##
  17 ## You should have received a copy of the GNU General Public License     ##
  18 ## along with this program.  If not, see <http://www.gnu.org/licenses/>. ##
  19 ##                                                                       ##
  20 ###########################################################################
  21
  22 ## HomePage : http://wiki.openstreetmap.org/wiki/PythonOsmApi
  23
  24 ###########################################################################
  25 ## History                                                               ##
  26 ###########################################################################
  27 ## 0.2.5   2009-10-09 implements NodesGet, WaysGet, RelationsGet         ##
  28 ##                               ParseOsm, ParseOsc                      ##
  29 ## 0.2.4   2009-10-06 clean-up                                           ##
  30 ## 0.2.3   2009-09-09 keep http connection alive for multiple request    ##
  31 ##                    (Node|Way|Relation)Get return None when object     ##
  32 ##                    have been deleted (raising error before)           ##
  33 ## 0.2.2   2009-07-13 can identify applications built on top of the lib  ##
  34 ## 0.2.1   2009-05-05 some changes in constructor -- chove@crans.org     ##
  35 ## 0.2     2009-05-01 initial import                                     ##
  36 ###########################################################################
  37
  38 __version__ = '0.2.5'
  39
  40 import httplib, base64, xml.dom.minidom, time
  41
  42 ###########################################################################
  43 ## Main class                                                            ##
  44
  45 class OsmApi:
  46
  47     def __init__(self, username = None, password = None, passwordfile = None, appid = "", created_by = "PythonOsmApi/"+__version__, api = "www.openstreetmap.org"):
  48
  49         # Get username
  50         if username:
  51             self._username = username
  52         elif passwordfile:
  53             self._username =  open(passwordfile).readline().split(":")[0].strip()
  54
  55         # Get password
  56         if password:
  57             self._password   = password
  58         elif passwordfile:
  59             for l in open(passwordfile).readlines():
  60                 l = l.strip().split(":")
  61                 if l[0] == self._username:
  62                     self._password = l[1]
  63
  64         # Get API
  65         self._api = api
  66
  67         # Get created_by
  68         if appid == "":
  69                 self._created_by = created_by
  70         else:
  71                 self._created_by = appid + " (" + created_by + ")"
  72
  73         # Initialisation
  74         self._CurrentChangesetId = -1
  75
  76         # Http connection
  77         self._conn = httplib.HTTPConnection(self._api, 80)
  78
  79     #######################################################################
  80     # Capabilities                                                        #
  81     #######################################################################
  82
  83     def Capabilities(self):
  84         raise NotImplemented
  85
  86     #######################################################################
  87     # Node                                                                #
  88     #######################################################################
  89
  90     def NodeGet(self, NodeId, NodeVersion = -1):
  91         """ Returns NodeData for node #NodeId. """
  92         uri = "/api/0.6/node/"+str(NodeId)
  93         if NodeVersion <> -1: uri += "/"+str(NodeVersion)
  94         data = self._get(uri)
  95         if not data: return data
  96         data = xml.dom.minidom.parseString(data.encode("utf-8"))
  97         data = data.getElementsByTagName("osm")[0].getElementsByTagName("node")[0]
  98         return self._DomParseNode(data)
  99
 100     def NodeUpdate(self, NodeData):
 101         """ Updates node with NodeData. Returns updated NodeData (without timestamp). """
 102         if self._CurrentChangesetId == -1:
 103             raise Exception, "No changeset currently opened"
 104         NodeData[u"changeset"] = self._CurrentChangesetId
 105         result = self._put("/api/0.6/node/"+str(NodeData[u"id"]), self._XmlBuild("node", NodeData))
 106         NodeData[u"version"] = int(result.strip())
 107         if u"timestamp" in NodeData: NodeData.pop(u"timestamp")
 108         return NodeData
 109
 110     def NodeDelete(self, NodeData):
 111         """ Delete node with NodeData. Returns updated NodeData (without timestamp). """
 112         if self._CurrentChangesetId == -1:
 113             raise Exception, "No changeset currently opened"
 114         NodeData[u"changeset"] = self._CurrentChangesetId
 115         result = self._delete("/api/0.6/node/"+str(NodeData[u"id"]), self._XmlBuild("node", NodeData))
 116         NodeData[u"version"] = int(result.strip())
 117         NodeData[u"visible"] = False
 118         if u"timestamp" in NodeData: NodeData.pop(u"timestamp")
 119         return NodeData
 120
 121     def NodeCreate(self, NodeData):
 122         """ Creates a node. Returns updated NodeData (without timestamp). """
 123         if self._CurrentChangesetId == -1:
 124             raise Exception, "No changeset currently opened"
 125         if NodeData.get(u"id", -1) > 0:
 126             raise Exception, "This node already exists"
 127         NodeData[u"changeset"] = self._CurrentChangesetId
 128         result = self._put("/api/0.6/node/create", self._XmlBuild("node", NodeData))
 129         NodeData[u"id"]      = int(result.strip())
 130         NodeData[u"version"] = 1
 131         if u"timestamp" in NodeData: NodeData.pop(u"timestamp")
 132         return NodeData
 133
 134     def NodeHistory(self, NodeId):
 135         """ Returns dict(NodeVerrsion: NodeData). """
 136         uri = "/api/0.6/node/"+str(NodeId)+"/history"
 137         data = self._get(uri)
 138         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 139         result = {}
 140         for data in data.getElementsByTagName("osm")[0].getElementsByTagName("node"):
 141             data = self._DomParseNode(data)
 142             result[data[u"version"]] = data
 143         return result
 144
 145     def NodeWays(self, NodeId):
 146         """ Returns [WayData, ... ] containing node #NodeId. """
 147         # GET node/#/ways TODO
 148         raise NotImplemented
 149
 150     def NodeRelations(self, NodeId):
 151         """ Returns [RelationData, ... ] containing node #NodeId. """
 152         # GET node/#/relations TODO
 153         raise NotImplemented
 154
 155     def NodesGet(self, NodeIdList):
 156         """ Returns dict(NodeId: NodeData) for each node in NodeIdList """
 157         uri  = "/api/0.6/nodes?nodes=" + ",".join([str(x) for x in NodeIdList])
 158         data = self._get(uri)
 159         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 160         result = {}
 161         for data in data.getElementsByTagName("osm")[0].getElementsByTagName("node"):
 162             data = self._DomParseNode(data)
 163             result[data[u"id"]] = data
 164         return result
 165
 166     #######################################################################
 167     # Way                                                                 #
 168     #######################################################################
 169
 170     def WayGet(self, WayId, WayVersion = -1):
 171         """ Returns WayData for way #WayId. """
 172         uri = "/api/0.6/way/"+str(WayId)
 173         if WayVersion <> -1: uri += "/"+str(WayVersion)
 174         data = self._get(uri)
 175         if not data: return data
 176         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 177         data = data.getElementsByTagName("osm")[0].getElementsByTagName("way")[0]
 178         return self._DomParseWay(data)
 179
 180     def WayUpdate(self, WayData):
 181         """ Updates way with WayData. Returns updated WayData (without timestamp). """
 182         if self._CurrentChangesetId == -1:
 183             raise Exception, "No changeset currently opened"
 184         WayData[u"changeset"] = self._CurrentChangesetId
 185         result = self._put("/api/0.6/way/"+str(WayData[u"id"]), self._XmlBuild("way", WayData))
 186         WayData[u"version"] = int(result.strip())
 187         if u"timestamp" in WayData: WayData.pop(u"timestamp")
 188         return WayData
 189
 190     def WayDelete(self, WayData):
 191         """ Delete way with WayData. Returns updated WayData (without timestamp). """
 192         if self._CurrentChangesetId == -1:
 193             raise Exception, "No changeset currently opened"
 194         WayData[u"changeset"] = self._CurrentChangesetId
 195         result = self._delete("/api/0.6/way/"+str(WayData[u"id"]), self._XmlBuild("way", WayData))
 196         WayData[u"version"] = int(result.strip())
 197         WayData[u"visible"] = False
 198         if u"timestamp" in WayData: WayData.pop(u"timestamp")
 199         return WayData
 200
 201     def WayCreate(self, WayData):
 202         """ Creates a way. Returns updated WayData (without timestamp). """
 203         if self._CurrentChangesetId == -1:
 204             raise Exception, "No changeset currently opened"
 205         if NodeData.get(u"id", -1) > 0:
 206             raise Exception, "This way already exists"
 207         WayData[u"changeset"] = self._CurrentChangesetId
 208         result = self._put("/api/0.6/way/create", self._XmlBuild("way", WayData))
 209         WayData[u"id"]      = int(result.strip())
 210         WayData[u"version"] = 1
 211         if u"timestamp" in WayData: WayData.pop(u"timestamp")
 212         return WayData
 213
 214     def WayHistory(self, WayId):
 215         """ Returns dict(WayVerrsion: WayData). """
 216         uri = "/api/0.6/way/"+str(WayId)+"/history"
 217         data = self._get(uri)
 218         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 219         result = {}
 220         for data in data.getElementsByTagName("osm")[0].getElementsByTagName("way"):
 221             data = self._DomParseWay(data)
 222             result[data[u"version"]] = data
 223         return result
 224
 225     def WayRelations(self, WayId):
 226         """ Returns [RelationData, ...] containing way #WayId. """
 227         # GET way/#/relations
 228         raise NotImplemented
 229
 230     def WayFull(self, WayId):
 231         """ Will not be implemented. """
 232         raise NotImplemented
 233
 234     def WaysGet(self, WayIdList):
 235         """ Returns dict(WayId: WayData) for each way in WayIdList """
 236         uri = "/api/0.6/ways?ways=" + ",".join([str(x) for x in WayIdList])
 237         data = self._get(uri)
 238         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 239         result = {}
 240         for data in data.getElementsByTagName("osm")[0].getElementsByTagName("way"):
 241             data = self._DomParseWay(data)
 242             result[data[u"id"]] = data
 243         return result
 244
 245     #######################################################################
 246     # Relation                                                            #
 247     #######################################################################
 248
 249     def RelationGet(self, RelationId, RelationVersion = -1):
 250         """ Returns RelationData for relation #RelationId. """
 251         uri = "/api/0.6/relation/"+str(RelationId)
 252         if RelationVersion <> -1: uri += "/"+str(RelationVersion)
 253         data = self._get(uri)
 254         if not data: return data
 255         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 256         data = data.getElementsByTagName("osm")[0].getElementsByTagName("relation")[0]
 257         return self._DomParseRelation(data)
 258
 259     def RelationUpdate(self, RelationData):
 260         """ Updates relation with RelationData. Returns updated RelationData (without timestamp). """
 261         if self._CurrentChangesetId == -1:
 262             raise Exception, "No changeset currently opened"
 263         RelationData[u"changeset"] = self._CurrentChangesetId
 264         result = self._put("/api/0.6/relation/"+str(RelationData[u"id"]), self._XmlBuild("relation", RelationData))
 265         RelationData[u"version"] = int(result.strip())
 266         if u"timestamp" in RelationData: RelationData.pop(u"timestamp")
 267         return RelationData
 268
 269     def RelationDelete(self, RelationData):
 270         """ Delete relation with RelationData. Returns updated RelationData (without timestamp). """
 271         if self._CurrentChangesetId == -1:
 272             raise Exception, "No changeset currently opened"
 273         RelationData[u"changeset"] = self._CurrentChangesetId
 274         result = self._delete("/api/0.6/relation/"+str(RelationData[u"id"]), self._XmlBuild("relation", RelationData))
 275         RelationData[u"version"] = int(result.strip())
 276         RelationData[u"visible"] = False
 277         if u"timestamp" in RelationData: RelationData.pop(u"timestamp")
 278         return RelationData
 279
 280     def RelationCreate(self, RelationData):
 281         """ Creates a relation. Returns updated RelationData (without timestamp). """
 282         if self._CurrentChangesetId == -1:
 283             raise Exception, "No changeset currently opened"
 284         if NodeData.get(u"id", -1) > 0:
 285             raise Exception, "This relation already exists"
 286         RelationData[u"changeset"] = self._CurrentChangesetId
 287         result = self._put("/api/0.6/relation/create", self._XmlBuild("relation", RelationData))
 288         RelationData[u"id"]      = int(result.strip())
 289         RelationData[u"version"] = 1
 290         if u"timestamp" in RelationData: RelationData.pop(u"timestamp")
 291         return RelationData
 292
 293     def RelationHistory(self, RelationId):
 294         """ Returns dict(RelationVerrsion: RelationData). """
 295         uri = "/api/0.6/relation/"+str(RelationId)+"/history"
 296         data = self._get(uri)
 297         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 298         result = {}
 299         for data in data.getElementsByTagName("osm")[0].getElementsByTagName("relation"):
 300             data = self._DomParseRelation(data)
 301             result[data[u"version"]] = data
 302         return result
 303
 304     def RelationRelations(self, RelationId):
 305         """ Returns list of RelationData containing relation #RelationId. """
 306         # GET relation/#/relations TODO
 307         raise NotImplemented
 308
 309     def RelationFull(self, RelationId):
 310         """ Will not be implemented. """
 311         raise NotImplemented
 312
 313     def RelationsGet(self, RelationIdList):
 314         """ Returns dict(RelationId: RelationData) for each relation in RelationIdList """
 315         uri = "/api/0.6/relations?relations=" + ",".join([str(x) for x in RelationIdList])
 316         data = self._get(uri)
 317         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 318         result = {}
 319         for data in data.getElementsByTagName("osm")[0].getElementsByTagName("relation"):
 320             data = self._DomParseRelation(data)
 321             result[data[u"id"]] = data
 322         return result
 323
 324     #######################################################################
 325     # Changeset                                                           #
 326     #######################################################################
 327
 328     def ChangesetGet(self, ChangesetId):
 329         """ Returns ChangesetData for changeset #ChangesetId. """
 330         data = self._get("/api/0.6/changeset/"+str(ChangesetId))
 331         data = xml.dom.minidom.parseString(data.encode("utf-8"))
 332         data = data.getElementsByTagName("osm")[0].getElementsByTagName("changeset")[0]
 333         return self._DomParseChangeset(data)
 334
 335     def ChangesetUpdate(self, ChangesetTags = {}):
 336         """ Updates current changeset with ChangesetTags. """
 337         if self._CurrentChangesetId == -1:
 338             raise Exception, "No changeset currently opened"
 339         if u"created_by" not in ChangesetTags:
 340             ChangesetTags[u"created_by"] = self._created_by
 341         result = self._put("/api/0.6/changeset/"+str(self._CurrentChangesetId), self._XmlBuild("changeset", {u"tag": ChangesetTags}))
 342         return self._CurrentChangesetId
 343
 344     def ChangesetCreate(self, ChangesetTags = {}):
 345         """ Opens a changeset. Returns #ChangesetId. """
 346         if self._CurrentChangesetId <> -1:
 347             raise Exception, "Changeset alreadey opened"
 348         if u"created_by" not in ChangesetTags:
 349             ChangesetTags[u"created_by"] = self._created_by
 350         result = self._put("/api/0.6/changeset/create", self._XmlBuild("changeset", {u"tag": ChangesetTags}))
 351         self._CurrentChangesetId   = int(result)
 352         self._CurrentChangesetTags = ChangesetTags
 353         self._CurrentChangesetCpt  = 0
 354         return self._CurrentChangesetId
 355
 356     def ChangesetClose(self):
 357         """ Closes current changeset. Returns #ChangesetId. """
 358         if self._CurrentChangesetId == -1:
 359             raise Exception, "No changeset currently opened"
 360         result = self._put("/api/0.6/changeset/"+str(self._CurrentChangesetId)+"/close", u"")
 361         CurrentChangesetId = self._CurrentChangesetId
 362         self._CurrentChangesetId = -1
 363         return CurrentChangesetId
 364
 365     def ChangesetUpload(self):
 366         raise NotImplemented
 367
 368     def ChangesetDownload(self, ChangesetId):
 369         """ Download data from a changeset. Returns list of dict {type: node|way|relation, action: create|delete|modify, data: {}}. """
 370         uri = "/api/0.6/changeset/"+str(ChangesetId)+"/download"
 371         data = self._get(uri)
 372         return self.ParseOsc(data.encode("utf-8"))
 373
 374     def ChangesetsGet(self):
 375         raise NotImplemented
 376
 377     #######################################################################
 378     # Other                                                               #
 379     #######################################################################
 380
 381     def Map(self):
 382         raise NotImplemented
 383
 384     def Trackpoints(self):
 385         raise NotImplemented
 386
 387     def Changes(self):
 388         raise NotImplemented
 389
 390     #######################################################################
 391     # Data parser                                                         #
 392     #######################################################################
 393
 394     def ParseOsm(self, data):
 395         """ Parse osm data. Returns list of dict {type: node|way|relation, data: {}}. """
 396         data = xml.dom.minidom.parseString(data)
 397         data = data.getElementsByTagName("osm")[0]
 398         result = []
 399         for elem in data.childNodes:
 400             if elem.nodeName == u"node":
 401                 result.append({u"type": elem.nodeName, u"data": self._DomParseNode(elem)})
 402             elif elem.nodeName == u"way":
 403                 result.append({u"type": elem.nodeName, u"data": self._DomParseWay(elem)})
 404             elif elem.nodeName == u"relation":
 405                 result.append({u"type": elem.nodeName, u"data": self._DomParseRelation(elem)})
 406         return result
 407
 408     def ParseOsc(self, data):
 409         """ Parse osc data. Returns list of dict {type: node|way|relation, action: create|delete|modify, data: {}}. """
 410         data = xml.dom.minidom.parseString(data)
 411         data = data.getElementsByTagName("osmChange")[0]
 412         result = []
 413         for action in data.childNodes:
 414             if action.nodeName == u"#text": continue
 415             for elem in action.childNodes:
 416                 if elem.nodeName == u"node":
 417                     result.append({u"action":action.nodeName, u"type": elem.nodeName, u"data": self._DomParseNode(elem)})
 418                 elif elem.nodeName == u"way":
 419                     result.append({u"action":action.nodeName, u"type": elem.nodeName, u"data": self._DomParseWay(elem)})
 420                 elif elem.nodeName == u"relation":
 421                     result.append({u"action":action.nodeName, u"type": elem.nodeName, u"data": self._DomParseRelation(elem)})
 422         return result
 423
 424     #######################################################################
 425     # Internal http function                                              #
 426     #######################################################################
 427
 428     def _http_request(self, cmd, path, auth, send):
 429         self._conn.putrequest(cmd, path)
 430         self._conn.putheader('User-Agent', self._created_by)
 431         if auth:
 432             self._conn.putheader('Authorization', 'Basic ' + base64.encodestring(self._username + ':' + self._password).strip())
 433         if send:
 434             send = send.encode("utf-8")
 435             self._conn.putheader('Content-Length', len(send))
 436         self._conn.endheaders()
 437         if send:
 438             self._conn.send(send)
 439         response = self._conn.getresponse()
 440         if response.status <> 200:
 441             response.read()
 442             if response.status == 410:
 443                 return None
 444             raise Exception, "API returns unexpected status code "+str(response.status)+" ("+response.reason+")"
 445         return response.read().decode("utf-8")
 446
 447     def _http(self, cmd, path, auth, send):
 448         i = 0
 449         while True:
 450             i += 1
 451             try:
 452                 return self._http_request(cmd, path, auth, send)
 453             except:
 454                 if i == 5: raise
 455                 if i <> 1: time.sleep(2)
 456                 self._conn = httplib.HTTPConnection(self._api, 80)
 457
 458     def _get(self, path):
 459         return self._http('GET', path, False, None)
 460
 461     def _put(self, path, data):
 462         return self._http('PUT', path, True, data)
 463
 464     def _delete(self, path, data):
 465         return self._http('DELETE', path, True, data)
 466
 467     #######################################################################
 468     # Internal dom function                                               #
 469     #######################################################################
 470
 471     def _DomGetAttributes(self, DomElement):
 472         """ Returns a formated dictionnary of attributes of a DomElement. """
 473         result = {}
 474         for k, v in DomElement.attributes.items():
 475             k = k #.decode("utf8")
 476             v = v #.decode("utf8")
 477             if k == u"uid"         : v = int(v)
 478             elif k == u"changeset" : v = int(v)
 479             elif k == u"version"   : v = int(v)
 480             elif k == u"id"        : v = int(v)
 481             elif k == u"lat"       : v = float(v)
 482             elif k == u"lon"       : v = float(v)
 483             elif k == u"open"      : v = v=="true"
 484             elif k == u"visible"   : v = v=="true"
 485             elif k == u"ref"       : v = int(v)
 486             result[k] = v
 487         return result
 488
 489     def _DomGetTag(self, DomElement):
 490         """ Returns the dictionnary of tags of a DomElement. """
 491         result = {}
 492         for t in DomElement.getElementsByTagName("tag"):
 493             k = t.attributes["k"].value #.decode("utf8")
 494             v = t.attributes["v"].value #.decode("utf8")
 495             result[k] = v
 496         return result
 497
 498     def _DomGetNd(self, DomElement):
 499         """ Returns the list of nodes of a DomElement. """
 500         result = []
 501         for t in DomElement.getElementsByTagName("nd"):
 502             result.append(int(int(t.attributes["ref"].value)))
 503         return result
 504
 505     def _DomGetMember(self, DomElement):
 506         """ Returns a list of relation members. """
 507         result = []
 508         for m in DomElement.getElementsByTagName("member"):
 509             result.append(self._DomGetAttributes(m))
 510         return result
 511
 512     def _DomParseNode(self, DomElement):
 513         """ Returns NodeData for the node. """
 514         result = self._DomGetAttributes(DomElement)
 515         result[u"tag"] = self._DomGetTag(DomElement)
 516         return result
 517
 518     def _DomParseWay(self, DomElement):
 519         """ Returns WayData for the way. """
 520         result = self._DomGetAttributes(DomElement)
 521         result[u"tag"] = self._DomGetTag(DomElement)
 522         result[u"nd"]  = self._DomGetNd(DomElement)
 523         return result
 524
 525     def _DomParseRelation(self, DomElement):
 526         """ Returns RelationData for the relation. """
 527         result = self._DomGetAttributes(DomElement)
 528         result[u"tag"]    = self._DomGetTag(DomElement)
 529         result[u"member"] = self._DomGetMember(DomElement)
 530         return result
 531
 532     def _DomParseChangeset(self, DomElement):
 533         """ Returns ChangesetData for the changeset. """
 534         result = self._DomGetAttributes(DomElement)
 535         result[u"tag"] = self._DomGetTag(DomElement)
 536         return result
 537
 538     #######################################################################
 539     # Internal xml builder                                                #
 540     #######################################################################
 541
 542     def _XmlBuild(self, ElementType, ElementData):
 543
 544         xml  = u""
 545         xml += u"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
 546         xml += u"<osm version=\"0.6\" generator=\"" + self._created_by + "\">\n"
 547
 548         # <element attr="val">
 549         xml += u"  <" + ElementType
 550         if u"id" in ElementData:
 551             xml += u" id=\"" + str(ElementData[u"id"]) + u"\""
 552         if u"lat" in ElementData:
 553             xml += u" lat=\"" + str(ElementData[u"lat"]) + u"\""
 554         if u"lon" in ElementData:
 555             xml += u" lon=\"" + str(ElementData[u"lon"]) + u"\""
 556         if u"version" in ElementData:
 557             xml += u" version=\"" + str(ElementData[u"version"]) + u"\""
 558         xml += u" visible=\"" + str(ElementData.get(u"visible", True)).lower() + u"\""
 559         if ElementType in [u"node", u"way", u"relation"]:
 560             xml += u" changeset=\"" + str(self._CurrentChangesetId) + u"\""
 561         xml += u">\n"
 562
 563         # <tag... />
 564         for k, v in ElementData.get(u"tag", {}).items():
 565             xml += u"    <tag k=\""+self._XmlEncode(k)+u"\" v=\""+self._XmlEncode(v)+u"\"/>\n"
 566
 567         # <member... />
 568         for member in ElementData.get(u"member", []):
 569             xml += u"    <member type=\""+member[u"type"]+"\" ref=\""+str(member[u"ref"])+u"\" role=\""+self._XmlEncode(member[u"role"])+"\"/>\n"
 570
 571         # <nd... />
 572         for ref in ElementData.get(u"nd", []):
 573             xml += u"    <nd ref=\""+str(ref)+u"\"/>\n"
 574
 575         # </element>
 576         xml += u"  </" + ElementType + u">\n"
 577
 578         xml += u"</osm>\n"
 579
 580         return xml
 581
 582     def _XmlEncode(self, text):
 583         return text.replace("&", "&amp;").replace("\"", "&quot;")
 584
 585 ## End of main class                                                     ##
 586 ###########################################################################