source: TI05-delivery/ows_framework/trunk/ows_server/ows_server/lib/base.py @ 2577

from pylons import Response, c, g, cache, request, session
from pylons.controllers import WSGIController
from pylons.decorators import jsonify, validate
from pylons.templating import render, render_response
from pylons.helpers import abort, redirect_to, etag_cache
from pylons.i18n import N_, _, ungettext
import ows_server.models as model
import ows_server.lib.helpers as h

from ows_common import exceptions as OWS_E
from ows_common.operations_metadata import OperationsMetadata, Operation, RequestMethod
from ows_common.get_capabilities import ServiceMetadata
import ows_common.xml
from elementtree import ElementTree as ET

class BaseController(WSGIController):
    def __call__(self, environ, start_response):
        # Insert any code to be run per request here. The Routes match
        # is under environ['pylons.routes_dict'] should you want to check
        # the action or route vars here
        return WSGIController.__call__(self, environ, start_response)
    
class OwsController(BaseController):
    def __call__(self, environ, start_response):

        # All OWS parameter names are case insensitive.
        req = request._current_obj()
        self.ows_params = {}
        for k in req.params:
            self.ows_params[k.lower()] = req.params[k]        

        try:
            self._fixOwsAction(environ)
            return super(OwsController, self).__call__(environ, start_response)
        except OWS_E.OwsError, e:
            return render_response('exception_report', report=e.report,
                                   format='xml')
            
 
    def _fixOwsAction(self, environ):
        # Override the Routes action from the request query parameter
        try:
            action = self.ows_params['request']
        except KeyError:
            raise OWS_E.MissingParameterValue('REQUEST parameter not specified', 'REQUEST')

        # Check action is a method in self
        if not getattr(self, action):
            raise OWS_E.InvalidParameterValue('request=%s not supported' % action, 'REQUEST')

        # override routes action with request
        environ['pylons.routes_dict']['action'] = action
        del self.ows_params['request']

    def _loadCapabilities(self):
        """
        creates an ows_common.get_capabilities.ServiceMetadata object
        by consulting the paste configuration and annotations in the
        controller definition.

        """

        # Deduce ows_endpoint from routes
        ows_endpoint = h.url_for(controller=request.environ['pylons.routes_dict']['controller'])

        # Get the server-level configuration data from an XML file
        config = request.environ['paste.config']
        sm_tree = ET.parse(config['ows_common_config'])
        sm = ows_common.xml.service_metadata(sm_tree.getroot())

        # Extract service-level parameters and constraint
        parameters = getattr(self, '_ows_parameters', {})
        constraints = getattr(self, '_ows_constraints', {})
        versions = getattr(self, '_ows_versions', [])

        # Extract operation-level parameters and constraints
        od = {}
        for attr in dir(self):
            op = getattr(self, attr)
            if hasattr(op, '_ows_name'):
                p = getattr(op, '_ows_parameters', {})
                c = getattr(op, '_ows_constraints', {})
                od[op._ows_name] = Operation(get=RequestMethod(href=ows_endpoint),
                                             post=None,
                                             parameters=p,
                                             constraints=c)
        
        sm.operationsMetadata = OperationsMetadata(od, constraints, parameters)
        sm.serviceIdentification.serviceTypeVersions = versions
        
        return sm

    def _renderCapabilities(self, template='ows/get_capabilities'):
        """
        The standard way of returning a Capabilities document.

        Each subclass should implement self._load_capabilities() and call
        this method to return a response object.

        """
        c.service_metadata = self._loadCapabilities()

        r = render_response(template, format='xml')
        r.headers['content-type'] = 'text/xml'
        return r


# Include the '_' function in the public names
__all__ = [__name for __name in locals().keys() if not __name.startswith('_') \
           or __name == '_']