How to convert TextBoxes with null values to empty strings

Question

I may be out of date, but one principle I adhere to is avoid nulls as much as possible. However what I have found is that for a strongly typed view in which the user inputs the properties of an object I want to save, if some fields are not entered they are assigned as null.Then when you try to save the changes, the validation fails. So rather than set each property to an empty string, how can I automatically set each TextBox on a form to default to an empty string rather than a null?

Answer 1

To be honest, I'd say your coding methodology is out of date and flawed. You should handle all possibilities, it's not hard. That's exactly what string.IsNullOrEmpty(value); is for.

I'm guessing your validation logic is something like:

if (value == string.Empty) { isValid = false; } 

So it doesn't handle the null values. You should replace that check so it also checks for nulls.

string value1 = null;
string value2 = string.Empty;

string.IsNullOrEmpty(value1); // true
string.IsNullOrEmpty(value2); // true

Answer 2

You could put the following attribute on your string-properties in your model:

[DisplayFormat(ConvertEmptyStringToNull=false)]

So whenever someone posts a form with empty text-fields, these will be an empty string instead of null...