Bleeding Edge

To force browser reloads ...

Scott says: Response.Cache.SetCacheability(HttpCacheability.NoCache)

OR

"<META http-equiv="Pragma" content="no-cache">

<META http-equiv="Expires" content="-1">"

Reading a web site into Excel

Sub Read_URL_Test()

With ActiveSheet.QueryTables.Add(Connection:="URL;http://XXXXXXXXXXXXX";, _
Destination:=Range("a1"))'write web-page to sheet

.BackgroundQuery = True
.TablesOnlyFromHTML = False
.Refresh BackgroundQuery:=False
.SaveData = True
End With
End Sub

Sampel SQL (inner join, convert to numbers with commas)

SELECT value, convert(varchar, convert(money,sum([cashflow])),1) FROM [IBEW_cashflows_050].[dbo].[Cashflows] inner join loop on cohort_year + ys = value group by value order by value

A sample javascript function

function check_profile() {
k1='sean'
k2='keys'
k3=k1+k2
kk= document.Form2.profiles.value
if (kk.substring(0,7) == "System:")
{
alert("eat dog food");
}
}

Debugging Javascript in ASP.NET

With Internet Explorer 6 and VS .NET, Microsoft has provided a way to tap into the HTML and JavaScript that Internet Explorer is running.

Open Internet Explorer, choose Tools | Internet Options. Click the Advanced tab and find Disable script debugging about halfway down the list. Make sure there is no check in the box next to this option. Click OK and close Internet Explorer. The browser is now ready to work with Visual Studio .NET to debug your application.

To begin exploring the basic functions of the debugger, start your project, return to Visual Studio and open the Running Documents window by selecting Debug | Windows | Running Documents from the Debug menu.

The Running Documents window will appear docked on the right edge of the IDE. The name of the page will appear in the window. Double-click the page and the HTML rendered to the browser when the ASPX page was evaluated by the server will be shown in a code window on the left.

Set breakpoints. Trace code. Have fun.

Binding Drop Downs to a DataView

On your page load ...

' the interest profiles
DBconnect()
sqlstr = "Select distinct profile_name from interest_profiles where user_name='System' or user_name='" & Session("username") & "'"
Dim data_adapter2 As New OleDb.OleDbDataAdapter(sqlstr, conn)
Dim data_set2 As New DataSet()
data_adapter2.Fill(data_set2, "interest_profiles")

Dim dv As New DataView
dv = data_set2.Tables("interest_profiles").DefaultView
dv.Sort = "profile_name"
profiles.DataSource = dv
profiles.DataTextField = "profile_name"
profiles.DataBind()

'second approach
'profiles.DataSource = data_set2.Tables("interest_profiles").DefaultView
'profiles.DataTextField = "profile_name"
'profiles.DataBind()

'first approach
'Dim dt2 As DataTable = data_set2.Tables.Item("interest_profiles")
'Dim dr2 As DataRow

'If dt2.Rows.Count > 0 Then
' For Each dr2 In dt2.Rows
' profiles.Items.Add(dr2("profile_name"))
' Next
'End If

profiles.SelectedIndex = 0
conn.Close()

If you want to update the drop down ...

'update the drop down
profiles.Items.Clear()
Dim dv As New DataView
dv = data_set.Tables("interest_profiles").DefaultView
dv.Sort = "profile_name"
profiles.DataSource = dv
profiles.DataTextField = "profile_name"
profiles.DataBind()
profiles.Items.FindByText(profile).Selected = True

Making queries safer

Say you need to query a database using a filed provided by the user (e.g. ID). If you do the normal query like

Select * from database where ID = id.text

you can get burned if the user enters an apostrophe, etc.

Instead use:

Dim dr As SqlDataReader
Dim cm As SqlCommand

' retrieve the customer
cm = cn.CreateCommand
With cm
.CommandType = CommandType.StoredProcedure
.CommandText = "getOrder"
.Parameters.Add("@OrderID", SqlDbType.UniqueIdentifier).Value = ID
End With
Dim customerID As String = _
CStr(cm.ExecuteScalar)

This was a tip R Lhotka provided at VBITS 2003 Florida.

Custom Validation code

CustomValidator Sample

---

Enter an even number:

controltovalidate="myTextBox"
errormessage="Entry required." display="none" />

controltovalidate="myTextBox"
clientvalidationfunction="clientValidate"
onServerValidate="serverValidate"
errormessage="Not an even number. Try again." display="none" />

displaymode="singleparagraph" showsummary=false showmessagebox />

---

Doing a Reset in .Net

If you are coding a normal input form in html you might use the following html to create a 'Reset' button that clears all the input controls on your form:

Normally, this works fine. However, I have found that on forms that use .Net validation controls, the button above will reset the data on the form, but does not reset error messages that are displayed from improper data. ie, the bad data is removed, but the messages remain.

A solution that works follows:

Use a server-side button instead.

(Note the CausesValidation="False". This is necessary so the click event will be fired even when there are errors displayed.)
In the code-behind, the event handler looks like this:
Private Sub btnReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnReset.Click
' this will reset selections
Response.Redirect("session_selections.aspx")
End Sub
where the 'session_selections.aspx' is the name of your page. This re-loads the entire page.

Need a Regex?

Here are some useful ones ...

date
^(?:(?:(?:0?[13578]|1[02])(\/|-|\.)31)\1|(?:(?:0?[1,3-9]|1[0-2])(\/|-|\.)(?:29|30)\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})$|^(?:0?2(\/|-|\.)29\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))$|^(?:(?:0?[1-9])|(?:1[0-2]))(\/|-|\.)(?:0?[1-9]|1\d|2[0-8])\4(?:(?:1[6-9]|[2-9]\d)?\d{2})$

email
^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$

floating point number including empty string
^[-+]?\d*\.?\d*$

phone
^[-+]?\d*\.?\d*$

credit card
^((4\d{3})|(5[1-5]\d{2})|(6011))-?\d{4}-?\d{4}-?\d{4}|3[4,7]\d{13}$