ObjectDataSource & GridView for variable length input lists

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John_H - 06 Jan 2006 22:27 GMT

Re: ASP.NET 2.0
I would like suggestions or code examples on how to collect a variable
length list of input data (item# & item quantity specifically).

I thought that I could accomplish this using a GridView that has ViewState
enabled, an ObjectDataSource to process the submitted list, textboxes for
getting new item data and an add button.

Does this approach sound feasible or are there better alternatives?
My problem is that I don't know yet how to make this happen.

BTW, I intend to use the input list of item data in a web service request
and then display the resultant web service response in another GridView.

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Thanks, John_H

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John_H - 19 Jan 2006 20:50 GMT

I ended up using the following ASP.NET 2.0 code to implement the dynamic
variable length collection of input items. The code behind code for this is
also listed.
I ended up not using the ObjectDataSource nor GridView, but I am using
ViewState to preserve the state of the entered items between page postbacks.

http://www.asp101.com/samples/form_dynamic_aspx.asp

...was also a helpful reference for this.
***
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb"
Inherits="_Default" EnableViewState="true" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<span style="font-size: 16pt; font-family: Arial; text-decoration:
underline">FRESTA.Net
- Freight Estimator using the ABC Freight Calculator<br />
</span>
<br />
<span style="font-size: 10pt; font-family: Arial">
<asp:Table ID="Input_Header" runat="server" BorderWidth="2px"
BorderColor="Gray" GridLines="Both">
<asp:TableHeaderRow runat="server" ><asp:TableHeaderCell
runat="server" ColumnSpan="4" HorizontalAlign="Left"
BackColor="LightGray">Inputs:</asp:TableHeaderCell></asp:TableHeaderRow>
<asp:TableRow runat="server">
<asp:TableCell runat="server">Ship-from:</asp:TableCell>
<asp:TableCell runat="server">
<asp:DropDownList ID="DL_dc" runat="server"
DataSourceID="SqlDataSource1"
DataTextField="dc_name"
DataValueField="dc_num_str"></asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:ABC_INTRANETConnectionString %>"
SelectCommand="SELECT [dc_name], [dc_num_str] FROM
[DistributionCenters]"></asp:SqlDataSource>
</asp:TableCell>
<asp:TableCell runat="server">Ship-to Zip
Code:</asp:TableCell>
<asp:TableCell runat="server">
<asp:TextBox ID="TB_Zip" runat="server" MaxLength="5"
Width="50"></asp:TextBox>
&nbsp<asp:RegularExpressionValidator ID="RE_valZip"
runat="server" ControlToValidate="TB_Zip" ErrorMessage="Invalid Zip Code"
ValidationExpression="[0-9]{5}"></asp:RegularExpressionValidator>
</asp:TableCell>
</asp:TableRow>

<asp:TableRow runat="server">
<asp:TableCell ColumnSpan="2">&nbsp</asp:TableCell>
<asp:TableCell runat="server">Address Type:</asp:TableCell>
<asp:TableCell runat="server">
<asp:DropDownList ID="DL_AdrTyp" runat="server">
<asp:ListItem Value="R">Residence</asp:ListItem>
<asp:ListItem Value="C">Business</asp:ListItem>
</asp:DropDownList>

</asp:TableCell>
</asp:TableRow>

<asp:TableRow runat="server">
<asp:TableCell runat="server" ColumnSpan="2"
VerticalAlign="Top">Ship Date:</asp:TableCell>
<asp:TableCell runat="server" ColumnSpan="2">
<asp:Calendar ID="Calendar1"
runat="server"></asp:Calendar>
</asp:TableCell>
</asp:TableRow>

<asp:TableRow runat="server">
<asp:TableCell runat="server" ColumnSpan="2">Ship
Time:</asp:TableCell>
<asp:TableCell runat="server" ColumnSpan="2">
<asp:DropDownList ID="DL_hours" runat="server">
<asp:ListItem Value="1" Text="1"></asp:ListItem>
<asp:ListItem Value="2" Text="2"></asp:ListItem>
<asp:ListItem Value="3" Text="3"></asp:ListItem>
<asp:ListItem Value="4" Text="4"></asp:ListItem>
<asp:ListItem Value="5" Text="5"></asp:ListItem>
<asp:ListItem Value="6" Text="6"></asp:ListItem>
<asp:ListItem Value="7" Text="7"></asp:ListItem>
<asp:ListItem Value="8" Text="8"></asp:ListItem>
<asp:ListItem Value="9" Text="9"></asp:ListItem>
<asp:ListItem Value="10" Text="10"></asp:ListItem>
<asp:ListItem Value="11" Text="11"></asp:ListItem>
<asp:ListItem Value="12" Text="12"></asp:ListItem>
</asp:DropDownList>
<asp:Label runat="server" Text="Label" Font-Bold="True"
Font-Size="Larger">&nbsp:&nbsp</asp:Label>
<asp:DropDownList ID="DL_minutes" runat="server">
<asp:ListItem Value="0" Text="00"></asp:ListItem>
<asp:ListItem Value="30" Text="30"></asp:ListItem>
</asp:DropDownList>&nbsp
<asp:DropDownList ID="DL_am_pm" runat="server">
<asp:ListItem Value="0" Text="AM"></asp:ListItem>
<asp:ListItem Value="1" Text="PM"></asp:ListItem>
</asp:DropDownList>
</asp:TableCell>
</asp:TableRow>

</asp:Table>

<br />

<asp:Table ID="Input_Detail" runat="server" BorderWidth="2px"
BorderColor="Gray" GridLines="Both">
<asp:TableHeaderRow runat="server"><asp:TableHeaderCell
runat="server" ColumnSpan="5" HorizontalAlign="Left"
BackColor="LightGray">Item Inputs:</asp:TableHeaderCell></asp:TableHeaderRow>
<asp:TableHeaderRow runat="server">
<asp:TableCell runat="server" Font-Underline="true">Item
#</asp:TableCell>
<asp:TableCell runat="server"
Font-Underline="true">Quantity</asp:TableCell>
<asp:TableCell runat="server">&nbsp</asp:TableCell>
</asp:TableHeaderRow>

<asp:TableRow runat="server">
<asp:TableCell runat="server">
<asp:TextBox ID="TB_item"
runat="server"></asp:TextBox>
</asp:TableCell>
<asp:TableCell runat="server">
<asp:TextBox ID="TB_qty" runat="server"></asp:TextBox>
</asp:TableCell>
<asp:TableCell runat="server">
<asp:Button ID="Btn_add" runat="server" Text="Add
New Item" OnCommand="btnAddItem_Click"/>
</asp:TableCell>
</asp:TableRow>

</asp:Table>

<asp:Panel ID="pnlItemList" runat="Server">
<asp:PlaceHolder ID="phText" runat="Server"></asp:PlaceHolder>
</asp:Panel>
<asp:Table ID="ItemsTable" BorderStyle="Solid" BorderWidth="1"
GridLines="Both" runat="Server">
<asp:TableHeaderRow runat="server">
<asp:TableHeaderCell Text=""></asp:TableHeaderCell>
<asp:TableHeaderCell Text="Item #"></asp:TableHeaderCell>
<asp:TableHeaderCell Text="Item
Description"></asp:TableHeaderCell>
<asp:TableHeaderCell
Text="Quantity"></asp:TableHeaderCell>
<asp:TableHeaderCell Text=""></asp:TableHeaderCell>
</asp:TableHeaderRow>
</asp:Table>
<asp:Button ID="Btn_GetABCFreight" runat="server" Text="Get ABC
Freight" OnCommand="btnGetABCFreight_Click" />
</span>
</div>
</form>
</body>
</html>

***
Imports System.Collections.Generic
Imports System.Text.RegularExpressions
Imports System.Configuration.ConnectionStringSettings
Imports System.IO
Imports System.Data.SqlClient
Imports System.Web.UI.WebControls

Partial Class _Default
Inherits System.Web.UI.Page

Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
Handles MyBase.Load

If Page.IsPostBack = True Then
Dim inum As Integer
Dim ilist As List(Of LineItem)

inum = ViewState("ItemCount")

If inum > 0 Then
ilist = ViewState("ItemList") 'Get previously entered item
list
Call Load_ItemsTable(ilist, sender, e)
End If
End If

End Sub '**Page_Init

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
Handles MyBase.Load

Dim dt_now As DateTime 'Current date & time
Dim new_hour As Integer 'New hour value for ship time

If Page.IsPostBack = False Then 'If 1st time page is posted

dt_now = System.DateTime.Now

'== Set selected date to current date
Calendar1.SelectedDate = dt_now.Date

'== Set the ship-time close to the current time
new_hour = dt_now.Hour
If dt_now.Minute > 0 And dt_now.Minute <= 30 Then
DL_minutes.SelectedIndex = 1 'Set ship minutes default as 30
Else
DL_minutes.SelectedIndex = 0 'Set ship minutes default as 00
new_hour += 1
If new_hour > 23 Then
new_hour = 0
End If
End If

If new_hour >= 12 Then
DL_am_pm.SelectedIndex = 1 'Set PM as select default
new_hour -= 12
Else
DL_am_pm.SelectedIndex = 0 'Set AM as select default
End If

If new_hour = 0 Then
DL_hours.SelectedIndex = 11
Else
DL_hours.SelectedIndex = new_hour - 1
End If

ViewState("ItemCount") = 0 'Set initial item count to
zero
End If

'If sender.ToString.Substring(1, 13) = "btnRemoveItem" Then
' Call btnRemoveItem_Click(sender, e)
'End If

If ViewState("ItemCount") = 0 Then
ItemsTable.Visible = False 'Hide the Items Table
Btn_GetABCFreight.Visible = False 'Hide the Get ABC Freight
button
Else
ItemsTable.Visible = True 'Display the Items Table
Btn_GetABCFreight.Visible = False 'Display the Get ABC Freight
button
End If

End Sub '**Page_Load

Protected Sub btnAddItem_Click(ByVal sender As Object, ByVal e As
CommandEventArgs)
Dim inum As Integer
Dim ilist As New List(Of LineItem)
Dim idsc As String 'Item description
Dim err_msg As String
Dim bItm_Ok As Boolean
Dim bQty_Ok As Boolean

inum = ViewState("ItemCount") 'Get #items presviously entered
If inum > 0 Then
ilist = ViewState("ItemList") 'Get previously entered item list
End If
idsc = ""
err_msg = ""

bItm_Ok = Validate_Item(TB_item.Text, ilist, idsc, err_msg)
bQty_Ok = Validate_Qty(TB_qty.Text)

If Not bItm_Ok Or Not bQty_Ok Then
If Not bItm_Ok Then
If err_msg = "" Then
err_msg = "Item # is invalid, please re-enter."
End If
End If
If Not bQty_Ok Then
err_msg = "Item Quantity is invalid, please re-enter."
End If
Call ShowMsg(err_msg) 'Display the error message
Else
inum += 1
Dim item = New LineItem(TB_item.Text, idsc, CInt(TB_qty.Text))

ilist.Add(item) 'Add item just entered to the item list
Call Load_ItemsTableRow(inum, item, sender, e) 'Add new item
to table

TB_item.Text = "" 'Clear input item# textbox
TB_qty.Text = "" 'Clear input quantity textbox
End If

'If ilist.Count <= 0 Then
' ItemsTable.Visible = False
'Else
' ItemsTable.Visible = True
'End If

ViewState("ItemCount") = inum
ViewState("ItemList") = ilist
End Sub 'btnAddItem_Click

Protected Sub Load_ItemsTable(ByVal ilist As List(Of LineItem), ByVal
sender As Object, ByVal e As EventArgs)

Dim i As Integer

If ilist.Count > 0 Then
For i = 0 To ilist.Count - 1 'Row loop - start
Call Load_ItemsTableRow((i + 1), ilist.Item(i), sender, e)
Next 'Row loop - end
Else
ItemsTable.Visible = False 'Hide ItemsTable if no items
Btn_GetABCFreight.Visible = False 'Hide the Get ABC Freight
button
End If

End Sub 'Load_ItemsTable

Protected Sub Load_ItemsTableRow(ByVal inum As Integer, ByVal li As
LineItem, ByVal sender As Object, ByVal e As EventArgs)
Dim row As New TableRow
Dim ic As Integer

For ic = 0 To 4 'Cell loop - start
Dim cell As New TableCell
Select Case ic
Case 0 'Sequence#
cell.Text = CStr(inum) & ")" & "&nbsp"
Case 1 'Item number
cell.Text = li.ItemNum
Case 2 'Item description
cell.Text = li.ItemName
Case 3 'Item quantity
cell.Text = CStr(li.ItemQty)
cell.HorizontalAlign = HorizontalAlign.Right
Case 4 'Remove button
Dim rBtn As New Button
rBtn.Text = "Remove"
rBtn.ID = "btnRemoveItem" & CStr(inum)
rBtn.Attributes.Add("CommandName", "rBtn_" & CStr(inum))
AddHandler rBtn.Click, AddressOf btnRemoveItem_Click
cell.Controls.Add(rBtn)
End Select
row.Cells.Add(cell) ' Add next cell
Next 'Cell loop - end
ItemsTable.Rows.Add(row) 'Add next row
ItemsTable.Visible = True 'Display the items in the
ItemsTable
Btn_GetABCFreight.Visible = True 'Display the Get ABC Freight
button

End Sub 'Load_ItemsTableRow

Protected Sub btnRemoveItem_Click(ByVal sender As Object, ByVal e As
EventArgs)

Dim ir As Integer 'Item row# to remove
Dim i As Integer 'Index
Dim inum As Integer 'Item count from ViewState
Dim it As Integer 'Rows in ItemsTable
Dim ilist As New List(Of LineItem)
Dim rBtn As Button
Dim strID As String
Dim strItem As String 'Item number string
Dim re As New Regex("(\D+)(\d+)") 'Get 1 or more numeric digits, $2
'--------------------($1 )($2 )----'(preceded by 1 or more
non-numeric digits, $1)

rBtn = sender
strID = re.Replace(rBtn.ID, "$2") 'Get row/sequence number from
button ID

If IsNumeric(strID) Then
ir = CInt(strID)
Else
ir = 0
End If

inum = ViewState("ItemCount") 'Get #items presviously entered
If inum > 0 Then
If ir > 0 And ir <= inum Then
ilist = ViewState("ItemList") 'Get previously entered item
list
inum -= 1 'Decrement #items entered
Else
Exit Sub 'Exit, invalid item selected for
removal
End If
Else
Exit Sub 'Exit, no items in item table
End If

strItem = ilist.Item(ir - 1).ItemNum 'Get the item number being
removed
ilist.RemoveAt(ir - 1) 'Remove selected item from the item
list

it = ItemsTable.Rows.Count - 1 'Count of non-header rows
For i = 1 To it 'Clear non-header rows
ItemsTable.Rows.RemoveAt(1) 'Delete 1st row, remaining rows
bubble up
Next
Call Load_ItemsTable(ilist, sender, e) 'Re-Load the ItemsTable
'Note: re-load is done to re-number the sequence numbers in column #1

ViewState("ItemCount") = inum
ViewState("ItemList") = ilist

Call ShowMsg("Item " & strItem & " was removed.")

End Sub 'btnRemoveItem_Click

Protected Function Validate_Item(ByVal item As String, ByVal ilist As
List(Of LineItem), ByRef name As String, ByRef err As String) As Boolean

name = ""
err = ""
If item = Nothing Then
Return False
End If
If item = "" Then
Return False
End If

Dim i As Integer

If ilist.Count > 0 Then
For i = 0 To ilist.Count - 1
If ilist.Item(i).ItemNum = item Then
err = "This item (" & item & ") has already been added
to the item list."
Return False
End If
Next
End If

Dim dbConn As String
dbConn =
ConfigurationManager.ConnectionStrings("abc_data_filesConnectionString").ConnectionString
Dim selStr As String
Dim sqlConn As New SqlConnection(dbConn)
Dim sqlCmd As SqlCommand
Dim sqlRdr As SqlDataReader
Dim obsDate As Date
Dim obsFlag As Char

Try
sqlConn.Open()
Catch ex As Exception
err = "SQL connection error: |" & ex.Message & "|, on " & dbConn
Return False
End Try

'** Get the item's description, additional description, obsolete
flag, and obsolete date
selStr = "SELECT DISTINCT itmdsc,itmdsa,itmobs,itmobd FROM
dai_itmmst WHERE itmnmb = '" & item & "'"
sqlCmd = New SqlCommand(selStr, sqlConn)

Try
sqlRdr = sqlCmd.ExecuteReader
Do While sqlRdr.Read()
obsFlag = sqlRdr.Item("itmobs")
If obsFlag = "Y" Then
obsDate = CDate(sqlRdr.Item("itmobd"))
If obsDate <= Now.Date Then
err = "Entered item (" & item & ") is obsolete."
Exit Do
End If
End If
name = sqlRdr.Item("itmdsc") & sqlRdr.Item("itmdsa")
Exit Do
Loop
Catch ex As Exception
name = ""
err = "SQL Select error: |" & ex.Message & "|."
End Try

sqlConn.Close()
If err = "" Then
Return True
Else
Return False
End If
End Function 'Validate_Item

Protected Function Validate_Qty(ByVal qty As String) As Boolean
If qty = Nothing Then
Return False
End If
If qty = "" Then
Return False
End If
If Not Regex.IsMatch(qty, "\d{1,3}") Then 'If Not in range 0-999
Then
Return False
End If
If CInt(qty) <= 0 Then
Return False
End If
Return True 'Valid quantity input
End Function 'Validate_Qty

Protected Sub ShowMsg(ByVal msg As String)
Dim lblText As New Label

lblText.Text = msg & "<BR />"
phText.Controls.Add(lblText)
phText.Visible = True

End Sub 'ShowMsg

Protected Sub btnGetABCFreight_Click(ByVal sender As Object, ByVal e As
CommandEventArgs)

End Sub 'btnGetABCFreight_Click

End Class '_Default

Signature

- John_H

> Re: ASP.NET 2.0
> I would like suggestions or code examples on how to collect a variable
[quoted text clipped - 9 lines]
> BTW, I intend to use the input list of item data in a web service request
> and then display the resultant web service response in another GridView.

Reply to this Message

ObjectDataSource & GridView for variable length input lists

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