M2M table in catalog builder

[Amarjeet Pal]

M2M table in catalog builder (Wizard)

There’s a helpful article on the ServiceNow Community about this, but here’s a quick summary using the Service Offering example:

• When a Service Offering is selected, the related list Available for Subscribers on the catalog item should be populated.
• This behavior can vary based on requirements like User Criteria.

To achieve this:

1. Create two Catalog Wizard Questions:

   • One for selecting the Service Offering.
   • One for populating the related list.

2. Mapping Difference:

   • The first question should have map to set = false.
   • The second should have map to set = true.

3. Technical Setup:

   • The first field must be a List Collector.
   • It should be placed on a Variable Set.
   • Ensure the OOTB Catalog OnChange client script is active on the Variable Set—this is essential for populating the related list dynamically.

function onChange(control, oldValue, newValue, isLoading) {

 var CATALOG_QUESTION_NAME =Service offering variable name;

 var CATALOG_PRODUCER_NAME = M2M producer set name ;

 var CATALOG_PRODUCER_QUESTION_NAME = 'service_offering';

 if (isLoading) {

  g_form.setDisplay(CATALOG_PRODUCER_NAME, false);

  convertRowValuesToCommaSeparatedString(CATALOG_QUESTION_NAME, CATALOG_PRODUCER_NAME, CATALOG_PRODUCER_QUESTION_NAME);

  return;

 }

 var valueArr = !newValue ? [] : newValue.split(',');

 addRows(CATALOG_PRODUCER_NAME, CATALOG_PRODUCER_QUESTION_NAME, valueArr);

}

//TODO: move to UI scripts and use it in here.

function addRows(producerSetName, producerSetQuestionName, includedValues) {

    var recordMap = getRecordMap(producerSetName, producerSetQuestionName);

    var ans = [];

    for (var i = 0; i < includedValues.length; i++) {

        var row = {};

        row[producerSetQuestionName] = includedValues[i];

  if (recordMap && recordMap[includedValues[i]])

   row['sys_id'] = recordMap[includedValues[i]];

        ans.push(row);

    }

    g_form.setValue(producerSetName, JSON.stringify(ans));

}

function convertRowValuesToCommaSeparatedString(questionName, producerSetName, producerQuestionName) {

    var value = g_form.getValue(producerSetName);

    try {

        value = JSON.parse(value);

    } catch (e) {

        value = [];

    }

    var ans = [];

    for (var i = 0; i < value.length; i++) {

        var row = value[i];

        if (row && row.hasOwnProperty(producerQuestionName))

            ans.push(row[producerQuestionName]);

    }

    g_form.setValue(questionName, ans.join());

}

function getRecordMap(producerSetName, producerQuestionName) {

    var fieldObj = g_form.$private.getField(producerSetName);

    if (fieldObj._recordMap)

        return fieldObj._recordMap;

    var originalValue = fieldObj.originalValue || '[]';

    var originalJSON;

    try {

        originalJSON = JSON.parse(originalValue);

    } catch (e) {

        originalJSON = [];

    }

    var recordMap = {};

    for (var i = 0; i < originalJSON.length; i++) {

        var obj = originalJSON[i];

        if (obj && obj[producerQuestionName] && obj['sys_id'])

            recordMap[obj[producerQuestionName]] = obj['sys_id'];

    }

    fieldObj._recordMap = recordMap;

    return fieldObj._recordMap;

}

This is a major step that isn’t documented. Everything else follows the out-of-the-box behavior—try to replicate it similar to how "Available for" (User Criteria ) works.

Thanks
Amarjeet Pal