Dealing with Carriage Returns in Web Service Methods

When returning data from a database through a Web Service (as a DataSet, or as an XML representation of the data in the DataSet), you may have issues with new lines (carriage return/line feed) in your string data. 

I use a SQL Server database. The "new line" data must be stored in the database like this: "\r\n". But, when passing this through a web service, it must be passed like this: "&#13". Consequently, to address this discrepancy in format, I use two methods in my Web Service base class: a ConvertCarriageReturnForGets() method and a ConvertCarriageReturnForSaves() method.

[WebService(Namespace = "http://mycompany.com/")]
public class BBWebServices : System.Web.Services.WebService
{
    #region Declarations

    private string CRLF    = "
";
    private string NewLine = "\r\n";

    #endregion

    #region Convert CarriageReturn Methods

    /// <summary>
    /// Converts CarriageReturn/LineFeed characters so they are passed correctly through the Web Service
    /// </summary>
    /// <param name="dt"></param>
    /// <param name="ColumnName"></param>
    protected void ConvertCarriageReturnForGets(DataTable dt, string ColumnName)
    {
        if (dt.Columns.Contains(ColumnName))
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                if (dt.Rows[i][ColumnName] != DBNull.Value)
                    dt.Rows[i][ColumnName] = dt.Rows[i][ColumnName].ToString().Replace(this.NewLine, this.CRLF);
            }
        }
    }
    /// <summary>
    /// Converts CarriageReturn/LineFeed characters so they are correctly saved to the database
    /// </summary>
    /// <param name="dt"></param>
    /// <param name="ColumnName"></param>
    protected void ConvertCarriageReturnForSaves(DataTable dt, string ColumnName)
    {
        if (dt.Columns.Contains(ColumnName))
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                if (dt.Rows[i][ColumnName] != DBNull.Value)
                    dt.Rows[i][ColumnName] = dt.Rows[i][ColumnName].ToString().Replace(this.CRLF, this.NewLine);
            }
        }
    }

    #endregion
}

Use the methods like this in your Web Service classes:

[WebService(Namespace = "http://mycompany.com/")]
public class Customer : BBWebServices
{
    [WebMethod(Description="Returns Customer Info for one customer")]
    public string GetCustomer(long CustomerKey)
    {
        CustomerBiz oBiz = new CustomerBiz();
        CustomerDataSet ds = oBiz.GetCustomer(CustomerKey);

        this.ConvertCarriageReturnForGets(ds.CustomerNotes, "notes");
        
        string XML = ds.GetXml();
        return XML;
    }
    [WebMethod(Description="Saves info for one customer")]
    public bool SaveCustomer(string ChangeXML, string DeleteXML)
    {
        CustomerDataSet dsChanged = new CustomerDataSet();
        CustomerDataSet dsDeleted = new CustomerDataSet();

        try
        {
            // FillWithXml() is a method I have defined in my DataSet classes
            // It simply uses the DataSet's ReadXml() method with a string reader
            dsChanged.FillWithXml(ChangeXML);
            if (DeleteXML != "")
                dsDeleted.FillWithXml(DeleteXML);
        }
        catch (Exception ex)
        {
            Message = ex.Message;
            return false;
        }

        CustomerBiz oBiz = new CustomerBiz();
        this.ConvertCarriageReturnForSaves(dsChanged.CustomerNotes, "notes");

        bool IsOK = o.SaveCustomer(dsChanged, dsDeleted);
        return IsOK;
    }
}