You will now add server side validation code to the frmPersonnel page. Currently, when the Submit button is pressed, the frmPersonnelVerified page is displayed. This is because the frmPersonnelVerified page is set as the Submit button's PostBackUrl property. Instead of having the page go directly to the frmPersonnelVerified page when the Submit button is pressed, we want to do some server side validation. If any of the validation rules fail, we will redisplay the frmPersonnel page with the fields in question highlighted in yellow with an error message displayed.
First, it is important to understand what is currently happening when the submit button is pressed. This is causing a postback of the form to the frmPersonnelVerified form. When this postback happens, all of the data in the fields on the frmPersonnel form are sent to the frmPersonnelVerified form as name value pairs. In the Page_Load code of frmPersonnelVerified these values are picked up from the Request object and displayed. Each name value pair will be in the Request object as the ID of the control containing the value and the value itself. We can pass data between pages by using Session state instead. In order to do validation on the values but still have the values visible on the frmPersonnelVerified page, we will need to change not only the PostBack URL of the frmPersonnel page but also how the frmPersonnelVerified form is getting the data - it will need to get it from Session state rather than from the Request object.
Make the following changes:
Clear the Submit button PostBackURLProperty on the frmPersonnel form.
In the btnSubmit_Click event handler get each value from the data entry fields and set Session state items for each.
Change the frmPersonnelVerified code behind to get the values from the Session state items you created in the previous step.
When you are done with these steps, you should be able to enter data on the frmPersonnel data entry form and then click the Submit button. The frmPersonnelVerified page should then be displayed with the values that were in the data entry fields on frmPersonnel.
Make sure this is all working before proceeding to the next steps.
Add a label to the frmPersonnel form with an ID of lblError. Do not place the label to the right or left of any of the controls on the form. Add it below the controls or above the controls. The text property of this label should be set to an empty string.
Add code to perform server side validation in response to the submit button being clicked. Here are the business rules we want to enforce (remember this will be server C# code in the frmPersonnel code behind): Fields may not be empty or filled with spaces. If any field is empty, turn that field background color to yellow and add to/create an error message to be shown in the error label. The end date must be greater than the start date. If the end date is less than the start date, turn both date fields yellow and add to/create an error message to be shown in the error label. If all fields validate properly then the session state items should be set properly and the user should see the frmPersonnelVerified form with all the values displayed.
Lab Hints: To set a value in session state do the following:
Session["txtFirstName"] = txtFirstName.Text;
"txtFirstName" is the key and txtFirstName.Text is the value.
To get this same value back from the session we use the key and the Session object as follows:
Session["txtLastName"].ToString()
There is a Trim method on the string object that will automatically remove spaces from the beginning and end of a string. Remember, you can turn an object like a Session item object into a string using the Convert class or just using it's ToString() method.
You may want to create variables to work with for validation rather than using the Request item objects directly.
To turn a string into a DateTime object you can use the DateTime method Parse. If you had a date value stored in a string called strDate, you could turn it into a DateTime object like this:
DateTime myDateTimeObject = DateTime.Parse(strDate);
You can compare two DateTime objects by using the DateTime.Compare method. If you had two DateTime objects called dt1 and dt2 you can check to see if dt1 is greater than dt2 by doing this:
if (DateTime.Compare(dt1,dt2) > 0)
DateTime.Compare will return a 0 if the two dates are equal, a 1 if dt1 is greater than dt2, and a -1 if dt1 is less than dt2.
If you put in an invalid date for either of the date fields, you will get an exception/server error when trying to parse the values. We will address this in a later lab - for now make sure you enter valid dates (valid meaning a date in the form of mm/dd/yyyy).
If I had a TextBox control that was called txtAge and you wanted to set it's background color you could do this:
txtAge.BackColor = System.Drawing.Color.Yellow;
Remember to clear the PostBackURL property of the submit button!
STEP 3: Verify and submit (10 points)
View the video above on what functions your lab should have so far.
Run your project. When you open the project, and go to the main menu form a record should be saved in the tblUserActivity table with the IP address, form name accessed (frmPersonnel), and the date accessed. When you click the View Activity button you should see at least one record with this information. The validation and error display should work for entering data. All navigation and hyperlinks should work.
Once you have verified that it works, save your project, zip up all files, and submit in the Dropbox.
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Personnel in Browser
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frmMain in Browser
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Display of frmUserActivity form
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NOTE: Make sure you include comments in the code provided where specified (where the " //Your comments here" is mentioned) and for any code you write, or else a five point deduction per item (form, class, function) will be made. You basically put two forward slashes, which start the comment; anything after the // on that line is disregarded by the compiler. Then type a brief statement describing what is happening in following code. Comments show professionalism and are a must in systems. As a professional developer, comments will set you apart from others and make your life much easier if maintenance and debugging are needed.