Invoke REST Web Service Policy Example

This example illustrates a simple sequence with a single task. The task executes the Invoke REST Web Service policy, which sends a GET request to Google Maps for the geographical coordinates of a specific address. Because this example does not require a request string, it does not specify a request data object. The response is stored in output data object named Response, which is a text type object.

Note: This example invokes an external web service that might require proxy server configuration for your web application server.

The following figure shows the workflow tree and workflow diagram for this example. The workflow has task-level data objects for the response and error values.

The workflow tree shows a workflow named Invoke REST Service that has task-level data objects named error code, error message, and response. The workflow has one task named Invoke Service with a policy named “Task Started –> Invoke REST Web Service”.

The data objects in the Invoke REST Web Service task have the following properties:

Data Object Label	Type	Value
Response	Long Text Object	None (It is populated by the web service. If the expected response could exceed 4000, then use the Long Text data type.)
Error Code	Number	None (It is populated if an error occurs.)
Error Message	Short Text	None (It is populated if an error occurs.)

The policy definition associated with the task is as follows:

Policy Property	Value
Name	Task Started`->`Invoke REST Web Service
Event	Task Started
Action	Invoke REST Web Service
Description	This policy is used to invoke an unregistered web service function over REST.
Web Service Location	http://maps.googleapis.com/maps/api/geocode/json?sensor=false&address=500%20SAS%20Campus%20Drive%2C%20Cary%2C%20NC
HTTP Method	GET
Content Type	None (The default is text/plain.)
Web Service Input	None
Web Service Output	None
Error Code	Invoke REST Web Service/Invoke Service/Error Code
Error Message	Invoke REST Web Service/Invoke Service/Error Message
User Name	None
Password	None

Note: The JSON syntax endpoint is specified, so the response is a JSON string.

The final response stored in the Response output data object is as follows:

{
   "results": [   {
      "address_components":       [
                  {
            "long_name": "500",
            "short_name": "500",
            "types": ["street_number"]
         },
                  {
            "long_name": "Sas Campus Drive",
            "short_name": "Sas Campus Dr",
            "types": ["route"]
         },
                  {
            "long_name": "Cary",
            "short_name": "Cary",
            "types":             [
               "locality",
               "political"
            ]
         },
                  {
            "long_name": "Cary",
            "short_name": "Cary",
            "types":             [
               "administrative_area_level_3",
               "political"
            ]
         },
                  {
            "long_name": "Wake",
            "short_name": "Wake",
            "types":             [
               "administrative_area_level_2",
               "political"
            ]
         },
                  {
            "long_name": "North Carolina",
            "short_name": "NC",
            "types":             [
               "administrative_area_level_1",
               "political"
            ]
         },
                  {
            "long_name": "United States",
            "short_name": "US",
            "types":             [
               "country",
               "political"
            ]
         },
                  {
            "long_name": "27513",
            "short_name": "27513",
            "types": ["postal_code"]
         }
      ],
      "formatted_address": "500 Sas Campus Drive, Cary, NC 27513, USA",
      "geometry":       {
         "location":          {
            "lat": 35.823976,
            "lng": -78.7579669
         },
         "location_type": "ROOFTOP",
         "viewport":          {
            "northeast":             {
               "lat": 35.8253249802915,
               "lng": -78.7566179197085
            },
            "southwest":             {
               "lat": 35.8226270197085,
               "lng": -78.75931588029151
            }
         }
      },
      "types": ["street_address"]
   }],
   "status": "OK"
}

Last updated: March 5, 2020