Convert User Input to YYYY-MM-DD Date Format

This workflow requests a date input from the user (in various formats) or a step of days starting from the current date. The input will then be converted into the designated target date using the pattern YYYY-MM-DD, which is the default format for Helmut4.

We begin with a Helmut4 Input Action, asking for a date or a date step:

The input is then passed into a JavaScript Action node, where an additional temporary variable is defined to set a maximum number of steps, ensuring that the user can't input a date like August 3rd, 2045.

// Check input for date pattern or integer
// Convert to date format yyyy-MM-dd
// Allows variants of yyyy MM dd / dd MM yyyy
// accepted input for US format: MM/dd/yyyy

// moovIT GmbH - Bernhard Dimmel
// Changelog: Aug 26th 2024
// Version 2.1
// Refactored complete logic to handle more input variants
// added integer input to define new period
// added error handling
// added max amount of extended date period via {stream.variable.maxPeriod}

// Function to check if a string is a valid date and return it in the format yyyy-MM-dd
function formatDate(input) {
    // Array of possible date formats
    var dateFormats = [
        "yyyy-MM-dd", "yyyy_MM_dd", "yyyy.MM.dd", "yyyy MM dd", 
        "dd-MM-yyyy", "dd_MM_yyyy", "dd.MM.yyyy", "dd MM yyyy", 
        "MM/dd/yyyy"
    ];

    // Function to parse and format a valid date
    function parseAndFormatDate(input, dateFormats) {
        for (var i = 0; i < dateFormats.length; i++) {
            // Create a SimpleDateFormat object for the current format
            var dateFormat = new java.text.SimpleDateFormat(dateFormats[i]);

            // Set lenient to false to ensure strict date parsing
            dateFormat.setLenient(false);

            try {
                // Parse the input string as a date
                var parsedDate = dateFormat.parse(input);

                // Format the parsed date back to the "yyyy-MM-dd" format
                var formattedDate = new java.text.SimpleDateFormat("yyyy-MM-dd").format(parsedDate);

                return formattedDate;
            } catch (e) {
                // Try the next format if parsing fails
            }
        }
        return null;
    }

    // Function to check if the date exceeds the xx-day limit
    function isDateExceedingLimit(date) {
        var currentDate = new java.util.Date();
        var calendar = java.util.Calendar.getInstance();
        calendar.setTime(currentDate);
        calendar.add(java.util.Calendar.DATE, {stream.variable.maxPeriod});
        var limitDate = calendar.getTime();

        return date.after(limitDate);
    }

    // First, try to parse the input as a date string
    var formattedDate = parseAndFormatDate(input, dateFormats);
    if (formattedDate) {
        var parsedDate = new java.text.SimpleDateFormat("yyyy-MM-dd").parse(formattedDate);
        if (isDateExceedingLimit(parsedDate)) {
            return "Error: The extended period is too long - max period is {stream.variable.maxPeriod} days!";
        }
        return formattedDate;
    }

    // If input is not a valid date, check if it's an integer (number of days to add)
    try {
        var daysToAdd = parseInt(input);
        if (!isNaN(daysToAdd)) {
            var currentDate = new java.util.Date();
            var calendar = java.util.Calendar.getInstance();
            calendar.setTime(currentDate);
            calendar.add(java.util.Calendar.DATE, daysToAdd);
            var newDate = calendar.getTime();

            if (isDateExceedingLimit(newDate)) {
                return "Error: The extended period is too long - max period is {stream.variable.maxPeriod} days!";
            }

            return new java.text.SimpleDateFormat("yyyy-MM-dd").format(newDate);
        }
    } catch (e) {
        // Handle parsing errors
    }

    return "Error: Not a valid date or integer input.";
}

// Define input and output
// Example: "2024-08-26" or "2"
var inputString = "{stream.variable.input-date}";

var result = formatDate(inputString);

// Return new date as yyyy-MM-dd
result;

The node will return either the calculated date or an error message.

The only limitation is with input formats: "dd MM yyyy" and "MM dd yyyy" would be interpreted incorrectly. Therefore, only the US format, "MM/dd/yyyy," is accepted.

However, the code can be adjusted to meet your specific format requirements.