CSV output

##CSV output

Implementation

For those interested in converting a homogeneous array of JavaScript objects to CSV, here is the code that I use on StackUsers.

It is freely offered without restriction.

jsonToCSV

function jsonToCSV(sourceRows, omitHeader, fieldsToIgnore)
{

    /// <summary>
    /// Converts an array of JSON objects to CSV.
    ///</summary>
    /// <param name="sourceRows" type="Object[]">
    /// An array of objects containing a single level of scalar fields.
    /// e.g. [{ foo: "bar", fu: true }, { foo: "baarbar", fu: false }]
    /// 
    /// The first element in the array will define the header row.
    /// </param>
    /// <param name="omitHeader" type="Boolean" optional="true">if true, header row is not emitted</param>
    /// <param name="fieldsToIgnore" type="Map" optional="true">a map of fields to ignore e.g. { field1:1,field4:1 }</param>

    /// <returns type="String"></returns>
    /// <author name="sky sanders" contact="http://skysanders.net/subtext" date="2010-09-19"/>

    function quote(value)
    {
        return '"' + value.replace(/"/g, '""').replace(/\r/g, "\\r").replace(/\n/g, "\\b") + '"';
    };
    function pad(n)
    {
        return n < 10 ? '0' + n : n;
    };

    var header = "";
    var rows = "";
    var headerComplete = false;

    for (var i = 0; i < sourceRows.length; i++)
    {
        var firstElement = true;
        var row = "";
        for (var key in sourceRows[i])
        {
            if (sourceRows[i].hasOwnProperty(key))
            {
                if (fieldsToIgnore && (key in fieldsToIgnore))
                {
                    continue;
                }

                if (!headerComplete)
                {
                    if (!firstElement)
                    {
                        header = header.concat(", ");
                    };
                    header = header.concat(key);
                };

                if (!firstElement)
                {
                    row = row.concat(", ");
                };

                var value = sourceRows[i][key];

                if (typeof value != 'undefined' && value !== null)
                {
                    if (value instanceof Date)
                    {
                        var dateResult = value.getUTCFullYear() + '-'
                                + pad(value.getUTCMonth() + 1) + '-'
                                + pad(value.getUTCDate()) + 'T'
                                + pad(value.getUTCHours()) + ':'
                                + pad(value.getUTCMinutes()) + ':'
                                + pad(value.getUTCSeconds()) + 'Z';
                        row = row.concat(dateResult);
                    }
                    else if ((value instanceof Boolean) || !isNaN(value))
                    {
                        row = row.concat(value.valueOf());
                    }
                    else
                    {
                        row = row.concat(quote(value.valueOf()));
                    }
                }
                firstElement = false;
            }
        }
        rows = rows.concat(row).concat("\r\n");
        headerComplete = true;
    }
    return omitHeader ? rows : header.concat("\r\n").concat(rows);
};