.NET Validation Controls MacDonald Ch. 8

1. .NET Validation ControlsMacDonald Ch. 8 MIS 324 Professor Sandvig

2. Today • What Validation controls do • Benefits & Limitations • Six Validation Controls • Implementation Example

3. What Validation Controls Do • Validate User inputs • ~75% of code for handling exceptions • Simplify task • Each control: • Validates user inputs on client-side using JavaScript • When possible • Validates all inputs on server • Writes client-side error message if invalid

4. Benefits and Limitations • Benefits • Convenience • Cut & paste • Bomb-proof • Server-side validation • Limitations • Must remember to check on server • Page.IsValid statement • Different interpretations of regular expressions • JavaScript vs. server • minor issue

5. Six Validation Controls • RequiredFieldValidator • Only validator that checks for NO entry • CompareValidator • Compares input to: datatype, constant, another control, database value, etc. • RangeValidator • Entry within a specified data range

6. Six Validation Controls • RegularExpressionValidator • Check format against a specific pattern • E-mail address, phone number, zip code, etc. • CustomValidator • Write own code • Server- or client-side • ValidationSummary • Summarizes all errors on page

7. Implementation • Often need > 1 validator per input • Only RequiredFieldValidator checks for empty fields • Page.IsValid • Check in event handler • if (!Page.IsValid) return; • Validation Groups • Allow validation controls to be assigned to groups • Page can have several groups • Act independently • Only group associated with postback event must have valid entries • Example: No groups, groups • Example: • Required, Compare, Range, & Custom (client- and server-side script) • Validation.aspx (source)

8. Summary • Easy to use • Flexible • Validate any type of input • Combines client- and server-side validation in one control • Bomb-proof server-side validation