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Child Poll Processor

The Poll Processor contains the logic that will be applied when polling a remote system for data.

The Poll Processor is a configuration record which contains the logic that will be applied when polling a remote system for data. There are three main scripts which are used to setup, execute and process the Poll Requests. The scripts given here are examples of how you might configure your Poll. The details of yours may differ depending on your requirements.

This child Poll Processor will take take each record passed to it from the parent Poll Processor and then make a fuller Poll Request against that record, processing it and deciding between multiple Messages in Unifi.

New Poll Processor

In Unifi Integration Designer, navigate to & open < Your Integration > (created following the Outbound Incident Guide).

Click the 'Poll Processors' icon & then New.

The fields to be configured for the New Poll Processor modal are as follows:

*Run parallel: Each Poll Request will have different input parameters (i.e. the sys_id of one of the updated Incidents passed from the Parent). We can therefore run concurrent Poll Requests on the different records without concern for overlap issues.

Your New Poll Processor modal should look like this:

'Parent' - Once we have created the Parent Poll Processor, we can then select it here. We have not scripted any business logic to run from the value in this field. It is given for documentary purposes only.

3) Submit and view to further configure the Poll Processor.

Setup Script

The Setup Script is the first script to run (it runs at the point in time the Poll Request is created). It is used to build the environment for the poll and define what it will do. We will use it to setup the URL that will be called.

Navigate to Scripts > Setup Script.

The initial Poll Processor fields to be configured are as follows:

The code in the Setup script field should look like this:

// Configure the new Poll Request record
(function(poll_request, poller, params) {

    var connection = poller.getIntegration().getActiveConnection();
    var cvars = connection.getVariables();

    // The list of fields to retrieve
    var fields = cvars.child_fields;

    // Target a specific incident whose sys_id has been passed in the params object
    poll_request.endpoint_url += '/table/incident/' + params.incident_id +
        '?sysparm_fields=' + encodeURIComponent(fields);

})(poll_request, poller, params);

Setup script: The parameters for which data to return are contained in the endpoint url.

fields: The table API will return all the data by default, so we choose to deliberately limit what is returned to the fields listed in this variable.

Endpoint URL: The value used in the poll_request.endpoint_url was initially generated using the ServiceNow REST API Explorer, substituting a connection variable in for the fields along with the sys_id of a specific incident to query. This value is appended to the existing endpoint url in the active connection before being added to the Poll Request.

Note: We have included the /table/incident element of the endpoint url because we used the truncated url in the Connection when following the Outbound Incident Guide. If you have used the full url there, then this element can be excluded here.

params: The params object is passed through to the subsequent scripts (and on to further Pollers, if required). This script has been passed the sys_id of a specific incident from the parent Poller.

Your Setup Script form should look like this:

5) Navigate to Request Script.

Request Script

The Request Script is used to reach into the remote system and execute the request. We will use the ServiceNow RESTMessageV2() web service to make a REST call to the URL defined in the Setup Script.

The next Poll Processor field to be configured is as follows:

The code in the Request script field should look like this:

// Process the request e.g. by executing a web service and returning the response
(function(poll_request, poller, connection, params) {

    var rm = new sn_ws.RESTMessageV2();
    rm.setEndpoint(poll_request.endpoint_url);
    rm.setHttpMethod('GET');
    rm.setRequestHeader('Accept', 'application/json');
    rm.setRequestHeader('Content-type', 'application/json');
    rm.setBasicAuth(connection.getBasicAuthUser(), connection.getBasicAuthPassword());

    // rm.setRequestBody(JSON.stringify(body));
    var resp = rm.execute();

    answer = resp.getBody() + '';

})(poll_request, poller, connection, params);

Request script: This script uses the ServiceNow RESTMessageV2() web service to make a REST call to the endpoint url created in the Setup script. It returns the body of the request as the answer which it passes to the Response script

Your Request Script form should look like this:

7) Navigate to Response Script.

Response Script

The Response Script is used to process the information returned from the remote system. We will pass this data to Unifi, telling it which Message to use to process the data.

The last Poll Processor field to be configured is as follows:

The code in the Response script field should look like this:

// Process the response returned by the request script
// The 'answer' variable from the request script is passed in here as the 'response' parameter 
(function (poll_request, poller, response, params) {

    var body = JSON.parse(response);

    // Nothing to do if no results were returned
    if ( body.result.length == 0 ) {
        poll_request.response_status = 'No Incidents returned\n\n' + JSON.stringify(body,null,2);
        return;
    }

    // Sample result (single Incident)
/*
{
  "result": {
    "sys_id": "0ecc4865db734010c3ebde82ca961960",
    "number": "INC0010107",
    "correlation_id": "INC0010345",
    "short_description": "Demo two - Fixing request",
    "description": "A long description",
    "state":"2",
    "sys_updated_on": "2020-04-02 14:00:00",
    "sys_updated_by": "a.user"
  }
}    
*/

    // Establish the environment
    var integration = poller.getIntegration();
    var config = integration.getConfig();
    var conn   = integration.getActiveConnection();
    var cvars  = conn.getVariables();

    var poll_helper = new x_snd_eb.PollHelper(poll_request);
    var info = [];

    // Use Unifi code to find the Bond for an Incident
    function get_bond(inc) {
        var bond = new x_snd_eb.Bond(config);
        bond.locateReference(integration,inc.correlation_id,inc.sys_id);
        if ( !bond.isValidRecord() ) { return null; }
        return bond; 
    }

    // Work out the message type to send to Unifi based upon the change of state
    function get_message_name(curr,prev) {

        // Default message type is an update
        var message_name = 'UpdateIncidentInbound';

        // Use the default type if we have no previous state
        if ( !prev || !prev.state ) { 
            return message_name; 
        }

        // Use the default type if there is no change in state
        if ( curr.state == prev.state ) { 
            return message_name; 
        }

        // We know the state has changed, check if it is Resolved (6)
        if ( curr.state == '6' ) {
            message_name = 'ResolveIncidentInbound';
        }

        return message_name;
    }

    function process_incident(inc) {

        // Log the incident number and time
        var inc_time = inc.sys_updated_on;
        info.push('Incident : ' + inc.number + ' (' + inc_time + ')');

        // Find the bond on which the previous data is stored
        var bond = get_bond(inc);

        // If no bond was found, ignore this incident
        if ( !bond ) {
            info.push('- Bond not found - Incident ignored');
            return;
        }

        // Get the data stored for the incident by a previous poll
        var previous_inc = bond.getDataObject('previous_inc',{ state : '2' });

        // Work out the message type to send into Unifi 
        var message_name = get_message_name(inc,previous_inc);
        info.push('- Message name: ' + message_name);

        // Set up the payload object for passing into Unifi
        var payload = {
            message : {
                name: message_name,
                source_reference: inc.sys_id
            },
            detail : {
                short_description : inc.short_description,
                description : inc.description,
                state : inc.state,
                close_code : inc.close_code,
                close_notes : inc.close_notes
            }
        };

        // Submit the message into Unifi
        poll_helper.processInbound({
            payload : JSON.stringify(payload)
        });

        // Save the current incident as the previous incident for the next poll
        bond.setDataObject('previous_inc',inc);

        // Update last update time (if later)
        var conn_time = conn.getData('last_update_time','');
        if ( inc_time > conn_time ) {
            conn.setData('last_update_time',inc_time);
        }

    }

    // Process the single result
    process_incident(body.result);

    poll_request.response_status = info.join('\n') + '\n\n' + JSON.stringify(body,null,2);

})(poll_request, poller, response, params);

Response script: This script parses the response into a body object to contain the result, (returning if it doesn't contain anything).

It then sets up some objects to help us; these include the essential PollHelper() function (which we initialise from the poll_request) along with two other functions: get_bond() to find the Bond for an Incident & get_message_name() to work out the message type to send to Unifi based upon the change of state.

After that it processes the passed in ticket - logging the incident number & time, finding the bond & returning any previous data stored on the bond, deciding which Message to use, setting up a payload object and submitting it to Unifi by calling the processInbound() method. It then saves the current incident as the previous incident for the next poll & checks whether the ticket was updated later than the last update time; if so, it sets and stores the last update time as that 'sys_updated_on' value (this 'last_update_time' is what the Setup script checks against when defining what the Poll will do).

After processing the single result, it is logged to the Response status field of the Poll Request.

Essential code: the following lines of code must be included in the response script to enable Unifi

var poll_helper = new x_snd_eb.PollHelper(poll_request);

poll_helper.processInbound({
            payload : JSON.stringify(payload)
        });

Payload object: We have chosen to structure the payload object (var payload) as we have. There is no obligation to keep the same structure. Yours can be defined to suit your requirements.

Message name: Unifi needs to know the message name in order to know how to process the inbound request. We can either set it in the payload (as we have), or declare a variable that sets it which is passed into the processInbound() function along with the payload. (Unifi will always check processInbound() first. If no Message name is set here it will use the 'Identify message script' on the Integration).

Your Response Script form should look like this:

9) Save the Poll Processor.

Now let's move on and configure the Child Poller.