Creating a Processing Task to Execute an FME Server Service

NOTE: Before you create a task to execute an FME server service, please read the article Creating a New Processing Task, as you will use the same Python framework described there.

To run an FME Server service from inside your task, you will need to use a POST request using REST. The following sample script demonstrates how to run an FME service from Python using the urllib2 module. You can edit this sample code and use it in your custom task's execute method.

The script is also available here.


# (C) Copyright 2014 Voyager Search
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#  http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import sys
import json
import urllib
import urllib2


def send_job(in_features, clip_features, out_workspace, out_coordinate_sys):
    """
    Submits a job to FME Server.

    :param in_features: Input features to be clipped (i.e. input shapefile)
    :param clip_features: Features used for clipping the input
    :param out_workspace: The location where the output features are created
    :param out_coordinate_sys: The ID for the coordinate system (i.e.  LL-WGS84)

    """
    # FME Service URL
    url = "http://localhost/fmejobsubmitter/Samples/ClipDataFME.fmw"

    # This is just an example assuming a service with these published parameters.
    # The keys are the FME service parameter names.
    params = {
        "Clippee": in_features,
        "Clipper": clip_features,
        "DestDataset": out_workspace,
        "OutCoordSys": out_coordinate_sys,
        "opt_showresult": "true",
        "opt_responseformat": "json"  # Response format will be json
    }

    # Create and post the request.
    try:
        password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
        password_mgr.add_password(None, url, 'user', 'pass')
        urllib2.install_opener(urllib2.build_opener(urllib2.HTTPBasicAuthHandler(password_mgr)))
        parameters = urllib.urlencode(params)
        response = urllib2.urlopen(url, parameters)
        if response.code == 200:  # Success
            response_dict = json.loads(response.read())
            srv_response = response_dict['serviceResponse']
            # Can ask the response for things like number of features, etc.
            if srv_response['fmeTransformationResult']['fmeEngineResponse']['numFeaturesOutput'] > 0:
                print('Clipped: {0}').format(in_features)
            else:
                print('No features were clipped.')
        else:
            print ('Error: {0}'.format(response.code))
    except urllib2.HTTPError as http_error:
        print(http_error)
    except urllib2.URLError as url_error:
        print(url_error)
# End send_job function


if __name__ == '__main__':
    # Set up the arguments - can be run standalone or via the command line.
    input_features = sys.argv[1] or "C:/GISData/Shapefiles/cities.shp"
    clip_features = sys.argv[2] or "C:/GISData/ShapeFiles/states.shp"
    output_workspace = sys.argv[3] or "C:/GISData/Shapefiles/clip_results"
    output_coordinate_system = sys.argv[4] or "LL-WGS84"
    send_job(input_features, clip_features, output_workspace, output_coordinate_system)