Avoiding multiple IF statements

Question

Suggestion in C# or VB.NET are welcome

I have the following code block. I'm tired of typing the same IF statement to check if the string has any lenght before assignning them to the class properties of Employee.

Is there any better to accomplish this?

        Dim title = txtTitle.Text.Trim
        Dim firstName = txtFirstName.Text.Trim
        Dim lastName = txtLastName.Text.Trim
        Dim middleName = txtMiddleName.Text.Trim
        Dim nativeName = txtNativeName.Text.Trim
        Dim mobile = txtMobile.Text.Trim
        Dim workEmail = txtWorkEmail.Text.Trim
        Dim peronsalEmail = txtPersonalEmail.Text.Trim
        Dim otherContact = txtOtherContact.Text.Trim
        Dim home = txtHome.Text.Trim
        Dim homeDir = txtHomeDir.Text.Trim
        Dim homeExt = txtHomeExt.Text.Trim
        Dim personalAddress = txtAddress.Text.Trim
        Dim office = txtOffice.Text.Trim
        Dim officeDir = txtOfficeDir.Text.Trim
        Dim officeExt = txtOfficeExt.Text.Trim

                   If title IsNot Nothing AndAlso title.Length > 0 Then
            newEmployee.Title = HttpUtility.HtmlEncode(title)
        End If

        If firstName IsNot Nothing AndAlso firstName.Length > 0 Then
            newEmployee.FirstName = HttpUtility.HtmlEncode(firstName)
        End If

        If lastName IsNot Nothing AndAlso lastName.Length > 0 Then
            newEmployee.LastName = HttpUtility.HtmlEncode(lastName)
        End If

        If middleName IsNot Nothing AndAlso middleName.Length > 0 Then
            newEmployee.MiddleName = HttpUtility.HtmlEncode(middleName)
        Else
            newEmployee.MiddleName = Nothing
        End If

        If nativeName IsNot Nothing AndAlso nativeName.Length > 0 Then
            newEmployee.NativeName = HttpUtility.HtmlEncode(nativeName)
        Else
            newEmployee.NativeName = Nothing
        End If

        If mobile IsNot Nothing AndAlso mobile.Length > 0 Then
            newEmployee.MobilePhone = HttpUtility.HtmlEncode(mobile)
        Else
            newEmployee.MobilePhone = Nothing
        End If

        If workEmail IsNot Nothing AndAlso workEmail.Length > 0 Then
            newEmployee.Email = HttpUtility.HtmlEncode(workEmail)
        Else
            newEmployee.Email = Nothing
        End If

        If peronsalEmail IsNot Nothing AndAlso peronsalEmail.Length > 0 Then
            newEmployee.PersonalEmail = HttpUtility.HtmlEncode(peronsalEmail)
        Else
            newEmployee.PersonalEmail = Nothing

        End If

        If otherContact IsNot Nothing AndAlso otherContact.Length > 0 Then
            newEmployee.OtherContact = HttpUtility.HtmlEncode(otherContact)
        Else
            newEmployee.OtherContact = Nothing
        End If

        If home IsNot Nothing AndAlso home.Length > 0 Then
            newEmployee.Home = HttpUtility.HtmlEncode(home)
        Else
            newEmployee.Home = Nothing
        End If

        If homeDir IsNot Nothing AndAlso homeDir.Length > 0 Then
            newEmployee.HomeDir = HttpUtility.HtmlEncode(homeDir)
        Else
            newEmployee.HomeDir = Nothing

        End If

        If homeExt IsNot Nothing AndAlso homeExt.Length > 0 Then
            newEmployee.HomeExtension = HttpUtility.HtmlEncode(homeExt)
        Else
            newEmployee.HomeExtension = Nothing
        End If

        If office IsNot Nothing AndAlso office.Length > 0 Then
            newEmployee.Office = HttpUtility.HtmlEncode(office)
        Else
            newEmployee.Office = Nothing
        End If

        If officeDir IsNot Nothing AndAlso officeDir.Length > 0 Then
            newEmployee.OfficeDir = HttpUtility.HtmlEncode(officeDir)
        Else
            newEmployee.OfficeDir = Nothing
        End If

        If officeExt IsNot Nothing AndAlso officeExt.Length > 0 Then
            newEmployee.OfficeExtension = HttpUtility.HtmlEncode(officeExt)
        Else
            newEmployee.OfficeExtension = Nothing
        End If

        If personalAddress IsNot Nothing AndAlso personalAddress.Length > 0 Then
            newEmployee.Address = HttpUtility.HtmlEncode(personalAddress)
        Else
            newEmployee.Address = Nothing
        End If

Answer 1

There are some bad things here, like not declaring your variables as string, but I'll answer your question:

private sub mycopy(value as string, ref target as string)
    value = value.trim
    if value.length > 0 then
        target = HttpUtility.HtmlEncode(value)
    end if 
end sub

mycopy(txtTitle.Text, ref title)
mycopy(txtFirstName.Text, ref firstName)

This is safe even when there is an existing value for title that you don't want changed --which I assume is what you want, otherwise why are you bothering to check?

You can go even further:

private sub mycopy(ctrl as TextBox, ref target as string)
    dim value as string = ctrl.Text.trim ' note declaration as string
    if value.length > 0 then
        target = HttpUtility.HtmlEncode(value)
    end if 
end sub

' use it this way:
dim title as string
dim firstName as string

mycopy(txtTitle, ref title)
mycopy(txtFirstName, ref firstName)

Answer 2

I'm tired of typing the same IF statement to check if the string has any lenght

Then don't. IF the newEmployee properties don't already have a significant value (and with a variable name like "newEmployee", they shouldn't), you can just call the function and the result is the same regardless.

If they might already have a significant value you don't want to overwrite, you have several options. You can hide the logic behind a simple helper function, or you can use reflection to iterate over the properties. But to me this mostly calls out as something that needs to be re-written because it will ultimately store html-encoded data in the database. And that's wrong.

ASP.Net labels and many other controls will html-encode data you assign to them for you. And some day you might want this data for a platform where you don't want to html-encode (a report writing tool, for example). Keep the data pure. Handle html encoding at the presentation level at output time.

Either way, you should declare your variables with an explicit type (String, in this case), and you should use the String.IsNullOrEmpty() function rather than just checking the length.

Answer 3

writing a function (or sub in vb) still requires you to type lots of function calls.

try something like the following (code untested, only pseudo-coding just now):

foreach (Control c in form/containerObject.Controls) {
    if ("TextBox" == c.GetType()) {
        TextBox tb = c as TextBox;
        if (tb.Length > 0) {
            newEmployee/targetObject.Title = HttpUtility.HtmlEncode(tb.Text);
        }
    }
}

or something like that :)

good luck.

Answer 4

Loop through the all controls on the form, determine if eachcontrol is a textbox and check if length is empty. You can use the String.IsNullOrEmpty() function. This way, you might need to use at most 1 or 2 if statements.

Answer 5

One possibility is to use a helper function, pseudo-code:

def setField (oldField, possibleVal):
    if possibleVal.Length > 0:
        return HttpUtility.HtmlEncode (possibleVal)
    return oldField

newEmployee.Title = setField (newEmployee.Title, title)
newEmployee.FirstName= setField (newEmployee.FirstName, firstName)
:
... and so on.

Answer 6

you can use a function..

newEmployee.title = ifNotNull(title);
....
....
newEmployee.Office = ifNotNull(office);

public string ifNotNull(string)
{
if(string.Length >0)
return HttpUtility.HtmlEncode(title);
else 
return "";
}