Question

I’m CSSing my project and would like to customize the font color for the feedback label. My project is built in 3 layers (DAL, BLL, normal page). In the BLL I catch exceptions and I guess this is where I would add the CSS stylesheet reference. Unfortunately, I can’t get it to work, this is what it looks like.

BLL

Public Function deleteCustByCustID(ByVal CustID As Integer) As Boolean
    If dataCust.DeleteCust(Cust) Then
        Throw New Exception("The customer was removed.")
        Return True
    Else
        Throw New Exception("The customer wasn't removed. Please try again.")
        Return False
    End If
End Function

ASPX.vb page

Try
    bllCust.deleteCustByCustID(CustID)
Catch ex As Exception
    lblFeedback.Text = ex.Message
End Try

I have my CSS pages stored in a CSS folder. I would like to assign the font color lime to a success and the font color red to a failure.

Any help is much appreciated!

Answer 1

Another option: if you have assigned an ID value to the markup for your “feedback” area, and if you added a runat="server" to that element, you can access the CssClass property in your code-behind file.

By way of example:

Markup

<div id="Feedback" runat="server"></div>

Code

Me.Feedback.CssClass="error"

Then you can use the CSS rules denoted by @rockerest in his answer.

EDIT:

Okay, I looked at your code again, and I see a big problem: you should NEVER use exceptions as a method of controlling program flow. That is probably error #1.

A not-too-uncommon method of returning a more meaningful result from your methods is to encapsulate a result object. Here is a simple example:

Public Class Result

    Public IsValid As Boolean
    Public Message As String

    Public Sub New(ByVal isValid As Boolean, ByVal message As String )
        IsValid = isValid
        Message = message
    End Sub

End Class

You would amend your current function to return a Result object instead of Boolean, and assign the values of the Result object depending on your query results:

Public Function deleteCustByCustID(ByVal CustID As Integer) As Result
    Dim result as New Result

    If dataCust.DeleteCust(Cust) Then
        result = new Result( true, "The customer was removed." )
    Else
        result = new Result( false, "The customer wasn't removed. Please try again." )
    EndIf

    Return result

End Function

Then, in whatever code calls the deleteCustByCustID method, you assign the Message property to the content of the feedback area and the CssClass that matches the IsValid state.

Make sense?

EDIT 2:

Okay, assuming you have a CSS class for errors, “.error” and a CSS class for, uh, not errors, “.success”. Then, let’s pretend the following snippet was inside an event handler or somesuchthing:

Dim result As new Result = deleteCustByCustID( 42 )

Now you have a Result object that has a IsValid state value (it will be either true or false) and a Message string value. Your next step is to apply the message to the feedback element’s (I’ll assume here that you use an ASP.NET Label control) Text property, and then, based on the value of result.IsValid, assign the correct class to the label’s CssClass property:

myFeedbackLabel.Text = result.Message
If result.IsValid Then
    myFeedbackLabel.CssClass = "success"
Else
    myFeedbackLabel.CssClass = "error"
EndIf

HTH.