1. PROG11044 - Advanced Web Apps
12/9/2018
Session 9.1
Calendar and Validation Controls
Using Sessions
Wendi Jollymore, ACES

2. Review Postback Page processing ViewState
The return trip from the server
Page processing
How it works (steps)
How the first load is different from postback
ViewState
Hidden __VIEWSTATE field
Using hash array
12/9/2018
Wendi Jollymore, ACES

3. Calendar Control Properties: SelectedDate VisibleDate Note that:
Contains a DateTime object
Set when user clicks a date on the control
Can be initialized or set at run time
VisibleDate
The current month that’s visible
To set, use the 1st of the month
Note that:
Selected date can stay the same even as visible date changes
12/9/2018
Wendi Jollymore, ACES

4. Calendar Control Events SelectionChanged VisibleMonthChanged
Occurs when selected date changes
User clicks a day, month selector, or week selector
Change SelelectionMode property to allow selection of weeks and month
VisibleMonthChanged
Occurs when user navigates months
Does not imply that selection changes!
12/9/2018
Wendi Jollymore, ACES

5. DateTime Class Constructor: DateTime(int year, int month, int day)
Constructs a new DateTime instance for the current year/month/day
12/9/2018
Wendi Jollymore, ACES

6. DateTime Class Properties: Date Day
Contains a DateTime object for the current DateTime instance
Time set to midnight
Day
Contains the day of the month for the current DateTime instance
Int32, 1 to 31
12/9/2018
Wendi Jollymore, ACES

7. DateTime Class Properties: DayOfWeek Month Year
A DayOfWeek enumeration value for the day of the week
E.g DayOfWeek.Sunday = 0
Month
The month # for the current DateTime instance
1 to 12
Year
The year for the current DateTime instance
12/9/2018
Wendi Jollymore, ACES

8. DateTime Class Properties: Now Today
Contains a DateTime object representing the computer’s current date and time
Static property
Today
Like DateTime.Now, but without the time
(midnight)
12/9/2018
Wendi Jollymore, ACES

9. DateTime Class Methods: AddDays(int days) AddMonths(int months)
Adds the specified number of days to the current DateTime instance
Returns a new DateTime instance
AddMonths(int months)
As above, but adds specified number of months
AddYears(int years)
As above, but adds specified number of years
12/9/2018
Wendi Jollymore, ACES

10. DateTime Class Methods: Compare(DateTime d1, DateTime d2)
Static method that takes two DateTime objects and returns Int32
Return value:
Is less than 0  d1 is earlier than d2
Is greater than 0  d1 is later than d2
Is 0  d1 and d2 are the same date/time
12/9/2018
Wendi Jollymore, ACES

11. DateTime Class Methods: CompareTo(DateTime d1)
Non-static method compares d1 with current DateTime instance
Returns Int32, also:
Less than 0  current instance is earlier than d1
Greater than 0  current instance is later than d1
Equal to 0  current instance and d1 are the same
12/9/2018
Wendi Jollymore, ACES

12. DateTime Class Methods: IsLeapYear(int year)
Static method, returns boolean
True of year is a leap year
False if year isn’t a leap year
ToString(), ToShortDateString(), ToLongDateString()
Returns various String representations of the current DateTime instance
12/9/2018
Wendi Jollymore, ACES

13. Exercise Add a Calendar control to a new page
Use the AutoFormat item in the task menu to format your calendar
You an customize by using the “Styles” category of properties in the Properties window
Add code to page load to init the calendar to today’s date:
Only if this is the first load
i.e. IsPostback == False!
12/9/2018
Wendi Jollymore, ACES

14. Calendar Tutorial Complete the Calendar tutorial in the notes
(ASP.NET/Controls and Events)
12/9/2018
Wendi Jollymore, ACES

15. Validation Controls A set of controls that do client-side validation
Controls are rendered as JavaScript
Types of Controls:
CompareValidator
RangeValidator
RegularExpressionValidator
RequiredFieldValidator
CustomValidator
12/9/2018
Wendi Jollymore, ACES

16. Validation Controls Common Properties: Display ErrorMessage
How the control is displayed on the page
Static – error message part takes up space, even when not showing
Dynamic – no space taken up by control when no error message
None – don’t show error message at all
ErrorMessage
The error message to display
Used by a ValidationSummary control
12/9/2018
Wendi Jollymore, ACES

17. Validation Controls Common Properties: Text ControlToValidate
The text the control will display on the page when there’s an error
When this is empty, contents of ErrorMessage property are shown instead
ControlToValidate
The ID of the control that this validator is validating
ValidationGroup
Set to a group name if you have multiple groups of controls to validate separately
12/9/2018
Wendi Jollymore, ACES

18. Validation Controls Try it out… set this up: 12/9/2018
Wendi Jollymore, ACES

19. Validation Controls
Drag a RequiredFieldValidator to the right of the first text box
ID: valReq
ControlToValidate: id of first box
ErrorMessage: “You must enter an address.”
Display: Dynamic
Load page and click button without typing address.
Add another of these validators for the “confirm ” text box (valReqConfirm)
12/9/2018
Wendi Jollymore, ACES

20. Validation Controls
Add a RegularExpressionValidator beside valReq
ID: valGood
ErrorMessage: “Your address isn’t valid.”
ControlToValidate: ID of text box
Display: Dyanmic
ValidationExpression:
Should be set to a regular expression
Choose “Internet Address” from the list
12/9/2018
Wendi Jollymore, ACES

21. Validation Controls Add a CompareValidator beside valReqConfirm
ID: val sMatch
ErrorMessage: “Your address doesn’t match.”
ControlToValidate: ID of confirm text box
Display: Dyanmic
ControlToCompare:
Should be the ID of the control you want to compare to – set to ID of text box
ValueToCompare property is used if you want to compare to a static value, instead
12/9/2018
Wendi Jollymore, ACES

22. Exercise Do the Validation exercises in the notes
ASP.NET / Controls and Events
12/9/2018
Wendi Jollymore, ACES

23. Sessions What is a Session? The time a visitor spends on the web site
Starts when they first loads a page
Ends when they leave your site, or the session automatically expires
Identified by a unique ID stored in a session cookie
Cookieless sessions can be used by storing id in the URL
You can store information in the Session object
A hash table
Can store entire objects, not just data
Session data is stored on server
12/9/2018
Wendi Jollymore, ACES

24. Sessions You can store data in a session like you would in ViewState:
Session[“userName”] = “Kaluha”;
The session variable is called userName
The value of the userName variable is “Kaluha”
12/9/2018
Wendi Jollymore, ACES

25. Sessions Tutorial Do the Sessions Tutorial in the notes
ASP.NET / Maintaining State / Sessions
Download the images!
Set up the page as instructed
12/9/2018
Wendi Jollymore, ACES

26. Sessions Tutorial Repeater control:
Repeats a set of markup/objects
You format the templates and it repeats them
You bind the control to a data source
It will fill the template with your data values
The repeater will be linked to a hash table of items and quantities
Book title will be key
Quantity will be value
12/9/2018
Wendi Jollymore, ACES

27. Sessions Tutorial <ItemTemplate> … </ItemTemplate>
Defines each “row item” in the repeater control
Each row in the control will be as defined in the template
12/9/2018
Wendi Jollymore, ACES

28. Sessions Tutorial
<asp:Label ID="Label1" width="70"
runat="server" text='<%# ... %>'>
</asp:Label>
<%# %> tags are for inline data binding expressions
Single quotes around text attribute value because inline expression requires double-quotes
The expression will be evaluated and result will appear in this label’s Text property
12/9/2018
Wendi Jollymore, ACES

29. Sessions Tutorial Container.DataItem DictionaryEntry is a class
((DictionaryEntry)Container.DataItem)
Container.DataItem
Refers to a specific item of data bound to the current container
Current container is the repeater template
Data Item will be an element in the hash table
DictionaryEntry is a class
Models a piece of data with a key/value pair
Has a Key property that contains the key portion, and Value property for value
Cast DataItem into DictionaryEntry so we can use the Key and Value properties
12/9/2018
Wendi Jollymore, ACES

30. Sessions Tutorial basketList.DataSource = basketTable;
basketList.DataBind();
DataSource property
The source of the data that will fill this control
Can be a hash table, data set, and other stuff you’ll learn later in the course
DataBind() method
Gets the data from the data source and populates the control
12/9/2018
Wendi Jollymore, ACES

31. Sessions Tutorial
Do the portion of the tutorial that takes you through the code
Session[“basket”] = basketTable;
Stores a reference to the basketTable hash table in the Session variable basket
Page_Prerender() event
Executes after control events have been executed, but before HTML is rendered
We need the results from the event handler in order to update the repeater
Page_Load is too soon, as it executes before the event handler
12/9/2018
Wendi Jollymore, ACES

32. For Next Class.. That last tutorial introduced Data Binding
We’ll look at this in more detail in the next class
12/9/2018
Wendi Jollymore, ACES