CSS Sprites

Good explanation of css sprites and how to use them

http://css-tricks.com/css-sprites/

Some other really good css stuff on this site too. One for the bookmarks.

jquery carousel

check it out

http://sorgalla.com/projects/jcarousel/

Rounded Corners with JQuery the Painless Way

Rounded corners with JQuery

http://code.google.com/p/jquerycurvycorners/downloads/list

It's this easy. Let's say you want all divs with the css class of rounded to have rounded corners. You just add this: $("div.rounded").corner(); inside the document.ready block.

Adding User Controls programmatically

If you haven't come across this problem yet when developing webforms projects then trust me, at some point you are going to.

Scenario

You have a view product page in a shopping cart application which has an "add to cart" button which adds one of these products to a shopping basket.
Your client comes along and says they want users not to have to drill down to the product detail page to add products to their baskets. So you are
now faced with having to work out how you will add an add to cart button to each product summary. Here's how you could deal with this problem.

1. Create a user control which displays a product summary and maybe call it something like displayProduct.ascx

2. User Controls are classes so expose a property or properties within the code behind file

For example let's say your Product Class has an ID property you could set your user control to have a productID property like this:


Private _productID As Integer

Public Property productID() As Integer
Get
Return _productID
End Get
Set(ByVal value As Integer)
_productID = value
End Set
End Property


2.a. take the add to cart button functionality from your product detail page and replicate it in your user control. So you might add a button called
AddToCart and code something like:

Protected Sub AddToCart_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles AddToCart.Click
Dim c As New Cart
Dim p As New Product
p = p.GetProductByID(me._productID)
c.AddProductToCart(p)
.... etc
End Sub

3. Add a placeholder control to your new product listings page to contain the user controls.

4. Now for the clever bit, let's say you have a ProductManager class which returns a list of Product class instances which you can pass into your
user controls, you can then loop through this list and add a displayProduct.ascx user control for each Product in your list. The code might look something
like this:



Public Sub DisplayHandsets()
Dim pm As New ProductManager
Dim pl As New List(Of Product)
pl = pm.GetProducts
Dim p As Product
For Each p In pl
'add user control for each product
Dim dp As displayProduct = CType(LoadControl("displayProduct.ascx"), displayProduct)
dp.productID = p.ID
' add the user control to your placeholder
phProducts.Controls.Add(dp)
Next
End Sub

5. Give yourself a big pat on the back for doing some serious nerd kung fu!

Regular Expressions 101 Part Two

In the previous post in this series we looked at a simple example of a regular expression:

^\d*$

which restricts input to either none or any number of digits.

The table below outlines a few slightly more complex variations of this regular expression and in which instances they would be valid.

"yes" means that particular number of digits would be valid input.

Quantity of numerical characters	+	*	{2}	{2,3}
Regular Expression	^\d+$	^\d*$	^\d{2}$	^\d{2,3}$
0		yes
1	yes	yes
2	yes	yes	yes	yes
3	yes	yes		yes
4	yes	yes

So to break this down "+" means one or more instances of the "pattern" specified
by the regular expression is required; "*" means none or any quantity of the
pattern need to be present; "{2}" means the length must be 2 instances of the
specified pattern; {2,3} means there must be either 2 or 3 instances of the
pattern present.

Here's a list of some characters found in regular expressions and what they mean:

• . - any character


• ? - optional i.e. there can be either none of these or any other quantity


• + - at least one or more


• * - none or any quantity

Regular Expressions and Grouping

You can also specify groups of characters to be matched by a regular expression. For example:

([A-Z][a-z]) specifies that the pattern must start with a Capital letter followed by a lower case character.

Clear as mud eh ;)

Regular Expressions 101 Part One

Today I managed to get a straightforward explanation for something which has always looked like gobbledy-gook to me i.e. Regular Expressions. So I thought I would share what I've picked up so far and add more as and when I get my head round this stuff.

So here's an example regular expression:

^\d{2}$

This would restrict input to numeric values only and two characters maximum length.

^ = start
\d = numbers only
{2} = how many
$ = end

There is a very useful regular expression testing tool here

Let's say you want numbers only i.e. no numbers or only numbers.

^\d*$

ASP.NET 3.5 Validation(): element is not supported

I am currently in the process of breaking my 3.5 cherry, loving the MVC stuff btw. Anyhoo I came across this problem where VS 2008 wasn't recognising 3.5 Webforms Controls in a 3.5 Webforms App! Every control I tried to add gave this warning:

Validation(): {control type} element is not supported

Solution:

Remove the Reference to the 3.5 Webforms Controls from the Web.config file:

<controls>
<add tagprefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<add tagprefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
</add>

Then rebuild the project. Go figure!

Thanks to this guy: http://forums.asp.net/t/1383876.aspx for the post.

String Arrays

Let's say you've got a bunch of email addresses all in one long string like:

me@bla.com,bla@bla.com,123@bla.com,noob@bla.com,helloworld@bla.com

And you want to separate these into individual email addresses.

Here's how:

Dim emails As String = "me@bla.com,bla@bla.com,123@bla.com,noob@bla.com,helloworld@bla.com"
Dim cleanEmails As String()
Dim s As String
cleanEmails = Split(emails, ",")

For Each s In cleanEmails
Response.Write(s & "
")
Next

This will write to the webform as:

me@bla.com
bla@bla.com
123@bla.com
noob@bla.com
helloworld@bla.com

Getting the difference between two dates

I've lost count of the number of times I've been asked to provide the difference between two dates and the equal number of times anything to do with dates as left mean tearing what's left of my hair out.

So here's a couple of useful things:

The TimeSpan Structure

Example Usage:

Get the difference in days between two dates:

Public Function GetDays(ByVal date1 As Date, ByVal date2 As Date) As Integer
Dim span As TimeSpan = date1 - date2
Return span.Days
End Function

Eg. Get number of days between now and 1st Jan 2000

GetDays(Date.Now, "01/01/00")

or alternatively we can use DateDiff

Public Function GetTheDays(ByVal date1 As Date, ByVal date2 As Date) As Integer
Return DateDiff(DateInterval.Day, date1, date2)
End Function