Metacat

#!/usr/bin/python

#

#  '$RCSfile$'

#  Copyright: 2000 Regents of the University of California

#

#   '$Author: perry $'

#     '$Date: 2006-12-15 10:23:32 -0800 (Fri, 15 Dec 2006) $'

# '$Revision: 3122 $'

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#

# TODO:

#  validate

#  getNextDocid

#  getNextRevision(docid)

#  getDocids(keyword=None)

#  query(keyword, returnfields)

#  queryDict => same as above but returns python dictionary data structure

import httplib, urllib

class MetacatClient:

    def __init__(self, server="knb.ecoinformatics.org", urlPath="/knb/metacat"):

        self.metacatUrlPath = urlPath

        self.metacatServer = server

        self.sessionid = None

    def getMetacatUrl(self):

        return "http://" + self.metacatServer +  self.metacatUrlPath

    def login(self, username, password, organization=None):

        if organization == 'NCEAS':

            uid = 'uid=%s,o=NCEAS,dc=ecoinformatics,dc=org' % username

        else:

            uid = username

        postdata = { 'action'   : 'login',

                     'qformat'  : 'xml',

                     'username' : uid,

                     'password' : password }

        response = self.postRequest(postdata) 

        if response.find("<login>") != -1:

            return True

        else:

            return False

    def logout(self):

        postdata = { 'action'   : 'logout',

                     'qformat'  : 'xml'}

        response = self.postRequest(postdata) 

        if response.find("<logout>") != -1:

            return True

        else:

            return False

    def read(self, docid, qformat="xml"):

        postdata = { 'action'   : 'read',

                     'qformat'  : qformat,

                     'docid'    : docid }

        response = self.postRequest(postdata) 

        # if error node returned

        if response.find("<error>") != -1:

            return False

        else:

            return response

    def insert(self, docid, doctext):

        postdata = { 'action'   : 'insert',

                     'doctext'  : doctext,

                     'docid'    : docid }

        response = self.postRequest(postdata) 

        # if error node returned

        if response.find("<error>") != -1:

            return False

        else:

            return response

    def update(self, docid, doctext):

        postdata = { 'action'   : 'update',

                     'doctext'  : doctext,

                     'docid'    : docid }

        response = self.postRequest(postdata) 

        return response

    def delete(self, docid):

        postdata = { 'action'   : 'delete',

                     'docid'    : docid }

        response = self.postRequest(postdata) 

        return response

    def squery(self, pathquery, qformat="xml"):

        postdata = { 'action'   : 'squery',

                     'qformat'  : qformat,

                     'query'    : pathquery }

        response = self.postRequest(postdata) 

        return response

    def postRequest(self, postdata):

        conn = httplib.HTTPConnection( self.metacatServer )

        params = urllib.urlencode( postdata )

        headers = { "Content-type" : "application/x-www-form-urlencoded", 

                    "Accept"       : "*/*"}

        # If we have an active session, set the cookie

        if self.sessionid is not None:

            headers['Cookie'] = self.sessionid

        conn.request( "POST", self.metacatUrlPath, params, headers )

        response = conn.getresponse()

        # If metacat responds with a new session id,

        # register it with the metacat client instance

        setcookie = response.getheader("set-cookie", None)

        if setcookie:

            jsid = setcookie.split(';')[0]

            if jsid[:11] == "JSESSIONID=":

               self.sessionid = jsid

        if response.status == 200:

           content = response.read()

        else:

           print " SERVER DID NOT RETURN 'OK'.... STATUS is " + str(response.status) 

           content = ""

        conn.close()

        return content