How can I make this call to log my exceptions recursive?

Question

I have the following code:

protected string formatException(Exception e)
{
    var exError = "<form>";
        if (e == null)
        {
            throw new ArgumentNullException("e");
        }
        exError += "<fieldset><legend><a href='#'>" +
                  "<span class='show-expanded'>collapse message</span>" +
                  "<span class='show-collapsed'>expand message</span>" +
                  "</a></legend><p>" + e.Message + "</p></fieldset>";
        exError += "<fieldset><legend><a href='#'>" +
                  "<span class='show-expanded'>collapse trace</span>" +
                  "<span class='show-collapsed'>expand trace</span>" +
                  "</a></legend><p>" + e.StackTrace + "</p></fieldset>";

        if (e.InnerException != null)
        {
            // same functionality but for the inner exception and the InnerException.InnerException
        }
    return exError + "</form>";
}

When called it formats the exception message. However I would like to make it include the InnerException and the InnerException.InnerException

Is there some way I could do this recursively or would it be better to put the message format in another function and call that?

score 6 · Answer 1 · answered Jun 22 '16 at 15:22

I know this is an old question and that there is already a marked answer. However, this is how I do it and I'll post this here in case it helps someone:

public static class ExceptionExtension
{
    public static string GetFullTrace(this Exception ex, bool recursive = true)
    {
        string trace = "";

        trace += "Name: " + ex.GetType().Name + "\n";
        trace += "Message: " + ex.Message + "\n";
        trace += "Stack Trace: " + (ex.StackTrace ?? "null") + "\n";

        if (recursive)
        {
            while (ex.InnerException != null)
            {
                ex = ex.InnerException;

                trace += "\n-------------------- Caused by: --------------------\n";
                trace += "Name: " + ex.GetType().Name + "\n";
                trace += "Message: " + ex.Message + "\n";
                trace += "Stack Trace: " + (ex.StackTrace ?? "null") + "\n";
            }
        }
        return trace;
    }
}

A slight change from previous answers is to use an extension method. This way one can simply call it as:

try 
{
    SomeOperationWhichMayThrow();
}
catch(Exception ex) 
{
    LogError(ex.GetFullTrace());
}

I have a project which contains many reusable utilities and extension methods, which I include in most of my projects. ExceptionExtension is one of those utils.

For better performance, consider using a StringBuilder instead.

score 3 · Answer 2 · answered May 24 '12 at 04:40

3

Try using something like

Exception ex = e;
while (ex != null)
{
   string s = ex.Message;
   ex = ex.InnerException;
}

answered May 24 '12 at 04:40

Adriaan Stander

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score 2 · Accepted Answer · answered May 24 '12 at 04:53

Here's what I'd do:

protected string formatException(Exception e)
{
    Func<string, string> createFieldSet =
        t =>
            "<fieldset><legend><a href='#'>" +
            "<span class='show-expanded'>collapse message</span>" +
            "<span class='show-collapsed'>expand message</span>" +
            "</a></legend><p>" + t + "</p></fieldset>";

    var exError = new StringBuilder("<form>");
    if (e == null)
    {
        throw new ArgumentNullException("e");
    }
    while (e != null)
    {
        exError.AppendLine(createFieldSet(e.Message));
        exError.AppendLine(createFieldSet(e.StackTrace));
        e = e.InnerException;
    }
    exError.AppendLine("</form>");
    return exError.ToString();
}

score 2 · Answer 4 · answered May 24 '12 at 04:55

I would do it like this:

        private string privateFormatException(Exception e)
        {
            var exError = String.Empty;
            if (e == null)
            {
                return exError;
            }
            exError += "<fieldset><legend><a href='#'>" +
                          "<span class='show-expanded'>collapse message</span>" +
                          "<span class='show-collapsed'>expand message</span>" +
                          "</a></legend><p>" + e.Message + "</p></fieldset>";
            exError += "<fieldset><legend><a href='#'>" +
                          "<span class='show-expanded'>collapse trace</span>" +
                          "<span class='show-collapsed'>expand trace</span>" +
                          "</a></legend><p>" + e.StackTrace + "</p></fieldset>";

            return exError + privateFormatException(e.InnerException);
        }



    protected string formatException(Exception e)
    {
        var exError = "<form>";
        if (e == null)
        {
            throw new ArgumentNullException("e");
        }
        exError += privateFormatException(e);
        return exError + "</form>";
    }

Kirin Yao · Answer 5 · 2012-05-24T05:00:55.787

I'm not sure if the follow code could solve it. It may need some format.

protected string formatException(Exception e)
{
    var exError = "<form>";
        if (e == null)
        {
            throw new ArgumentNullException("e");
        }
        exError += "<fieldset><legend><a href='#'>" +
                  "<span class='show-expanded'>collapse message</span>" +
                  "<span class='show-collapsed'>expand message</span>" +
                  "</a></legend><p>" + e.Message + "</p></fieldset>";
        exError += "<fieldset><legend><a href='#'>" +
                  "<span class='show-expanded'>collapse trace</span>" +
                  "<span class='show-collapsed'>expand trace</span>" +
                  "</a></legend><p>" + e.StackTrace + "</p></fieldset>";

        if (e.InnerException != null)
        {
            exError += formatException(e.InnerException);
        }
    return exError + "</form>";

}

EDIT

protected string FormatException(Exception e)
{
    if (e == null)
    {
        throw new ArgumentNullException("e");
    }
    var exError = "<form>";
    exError += FormatExceptionInternal(e);
    return exError + "</form>";
}

private string FormatExceptionInternal(Exception e)
{
    var exError = "";        
    exError += "<fieldset><legend><a href='#'>" +
              "<span class='show-expanded'>collapse message</span>" +
              "<span class='show-collapsed'>expand message</span>" +
              "</a></legend><p>" + e.Message + "</p></fieldset>";
    exError += "<fieldset><legend><a href='#'>" +
              "<span class='show-expanded'>collapse trace</span>" +
              "<span class='show-collapsed'>expand trace</span>" +
              "</a></legend><p>" + e.StackTrace + "</p></fieldset>";

    if (e.InnerException != null)
    {
        exError += FormatExceptionInternal(e.InnerException);
    }
    return exError;    
}

You can't nest forms in HTML, so you would have to remove the form tags from the recursive calls. — Ian Newson, May 24 '12 at 04:47

Talha · Answer 6 · 2012-05-24T05:34:16.693

Your FormatException method should be like that, do not need to declare exError variable as class level, declare it in the function and just return..

        protected string formatException(Exception e)
        {
            var exError = string.Empty;
            if (e == null)
            {
                throw new ArgumentNullException("e");
            }
            exError += "<fieldset><legend><a href='#'>" +
                      "<span class='show-expanded'>collapse message</span>" +
                      "<span class='show-collapsed'>expand message</span>" +
                      "</a></legend><p>" + e.Message + "</p></fieldset>";
            exError += "<fieldset><legend><a href='#'>" +
                      "<span class='show-expanded'>collapse trace</span>" +
                      "<span class='show-collapsed'>expand trace</span>" +
                      "</a></legend><p>" + e.StackTrace + "</p></fieldset>";

            if (e.InnerException != null)
            {
                exError += formatException(e.InnerException);
            }
            return exError;

        }

You can call this function like that and i hope so it will work for recursive as well.. Using of above method is

   StringBuilder sb = new StringBuilder();
   sb.Append("<form>");
   sb.Append(formatException(new Exception()));// pass your own exception
   sb.Append("</form>");
   string strException = sb.ToString();

In your case pass your own exception...

How can I make this call to log my exceptions recursive?

6 Answers6