A/B/C Compare Script

A/B/C Compare lets you validate a scan by comparing two or three values against each other — for example, a scanned barcode against the answer to a follow-up question, instead of against another scan. Paste this script into a Custom On-Device Validation (COV) script to turn it on.

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// Include __ORIGINAL__ in your override to show the original response text
var _validText = "MATCHED";        // Optional override, e.g. "Nice Job!\n__ORIGINAL__"
var _invalidText = "NOT MATCHED";  // Optional override, e.g. "Try Again"

// If you specify an error message and change _invalidText to false, a mismatch will block submit
var _errorMessage = false;

// When false, _valueA only needs to be a substring of _valueB
var isExactMatch = true;

// Prefix/suffix applied before comparing values
var prefixValueA = "";
var suffixValueA = "";

var prefixValueB = "";
var suffixValueB = "";

var prefixValueC = "";
var suffixValueC = "";

function getValue(valType, dataJson) {
    valType = valType.toUpperCase();

return valType === "SCAN" ? dataJson.scanValue :
           valType === "RESPONSE" ? dataJson.scanResponse :
           valType === "QUESTION" ? getAnswerVal(false, dataJson.answers) :
           getAnswerVal(valType, dataJson.answers); // Assume valType is a question ID
}

function crCustomValidate(dataJson) {
    if (dataJson.scanStatus && dataJson.scanStatus == "1") {
        var primary = prefixValueA + getValue(_valueA, dataJson) + suffixValueA;
        var secondary = prefixValueB + getValue(_valueB, dataJson) + suffixValueB;

var isValid = isExactMatch
            ? primary === secondary
            : (typeof secondary === "string" && secondary.indexOf(primary) !== -1);

if (isValid && _valueC !== false) {
            var tertiary = prefixValueC + getValue(_valueC, dataJson) + suffixValueC;
            isValid = isExactMatch
                ? primary === tertiary
                : (typeof tertiary === "string" && tertiary.indexOf(primary) !== -1);
        }

var obj = {
            scanStatus: isValid ? "1" : "0",
            scanResponse: dataJson.scanResponse ?? ""
        };

if (isValid && _validText !== false) {
            obj.scanResponse = _validText.replace("__ORIGINAL__", dataJson.scanResponse ?? "");
        } else if (!isValid) {
            if (_invalidText !== false) {
                obj.scanResponse = _invalidText.replace("__ORIGINAL__", dataJson.scanResponse ?? "");
            } else if (_errorMessage !== false) {
                obj.errorMessage = _errorMessage.replace("__ORIGINAL__", dataJson.scanResponse ?? "");
            }
        }

return JSON.stringify(obj);
    }

return JSON.stringify(dataJson);
}
</script>

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