Exception handling

References

Creating and Throwing Exceptions

Catch

Ensure the error is logged in a catch.
Actions returning a page, view or partial should return the appropriate error page.
Return the correct notification to user if elements are changed during execution or for AJAX/JSON responses.

// Log error
// Return correct error page/partial
public PartialViewResult PersonalDetails(int discussionId)
{
    try
    {
        return PartialView("_DiscussionPersonalDetails", new DiscussionPersonalDetailsViewModel(SessionHandler, discussionId));
    }
    catch (Exception ex)
    {
        ErrorUtilities.LogException(ex);
        return PartialView("_Error");
    }
}


// Log error
// Return correct error notification
[HttpPost]
public ActionResult Approve(int id, DiscussionSection activeTab)
{
    try
    {
        ApproveDiscussion(id, DiscussionStatus.COMPLETED);
        return Json(new { success = true, message = "Successfully approved.", redirectUrl = Url.EncryptedAction("Index", new { id, activeTab }) });
    }
    catch (Exception ex)
    {
        ErrorUtilities.LogException(ex);
        return Json(new { success = false, message = "There was a problem saving this section." });
    }
}


// Log error
// Return correct error notification
if (itemDisplaySetting == ItemDisplaySetting.Hide)
    HidePathwayStep(ref e);
else
{
    try
    {
        var step = pwStep.Fetch(sessionHandler, Int32.Parse(hfObjectID.Value));

    }
    catch (Exception ex)
    {
        ErrorUtilities.LogException(ex);
        lblReferenceDescription.Text = string.Format("{0}{1}", " Message: ", ex.Message);
    }
}

When to catch

Applying exceptions are usually done for the following cases:

• Logging of error and returning an error page/message:
  • Action called by user
  • Operation required for all following processes where normal NULL or content checks may not be sufficient.
• Logging of error, setting error message/property and continuing with next process