Binding to a DropDown list in a Footer Row

I typically use a separate ObjectDataSource that I place outside the GridView for clarity and easy of access in the CodeBehind. Alternatively, you could load it by hand using FindControl or declaring an OnLoad handler.

<footertemplate>
    <asp:DropDownList ID="inDataAssetIDFooter" runat="server" DataSourceID="dsDataAsset" 
        DataValueField="ID" DataTextField="Name" CssClass="DropDownList" AppendDataBoundItems="true">
        <asp:ListItem Value="0">Select Data Asset</asp:ListItem>
    </asp:DropDownList>
    <asp:CompareValidator ID="vldDANameFooter" runat="server" 
    Operator="GreaterThan" ValueToCompare="0" ControlToValidate="inDataAssetIDFooter" 
    Text="*" ErrorMessage="Data Asset is Required"/>
</footertemplate>

<asp:ObjectDataSource ID="dsDataAsset" runat="server" SelectMethod="GetUnRelatedDataAssetsByAppID"
    TypeName="MyProj.Lib.DataAssetDAL">
    <SelectParameters>
        <asp:QueryStringParameter Name="ID" QueryStringField="PID" Type="Int32" />
    </SelectParameters>
</asp:ObjectDataSource>

FileUpload file type validation using regular expression validator

The MSDN docs have an excellent example of how to perform file type validation using regular expressions. I tweaked the implementation to allow for configuration via the web.config:

<asp:RegularExpressionValidator
id="vldDocument" runat="server"
ValidationExpression=""
OnLoad="Setup_Doc_Validator"
ControlToValidate="inDocument" />

The codebehind gets the following handler:

    Protected Sub Setup_Doc_Validator(ByVal sender As Object, ByVal e As System.EventArgs)
       Dim docValidator As RegularExpressionValidator = CType(sender, RegularExpressionValidator)

       docValidator.ValidationExpression = DocumentDAL.GetValidationRegularExpression
       docValidator.ErrorMessage = String.Format(ProjectConstants.DOC_TYPE_ERROR_MESSAGE, _
           DocumentDAL.GetAllowableTypes())
   End Sub

    Public Shared Function GetValidationRegularExpression() As String
      Dim allowableTypes As String = DocumentDAL.GetAllowableTypes()
      Dim regEx As String = "^(([a-zA-Z]:)|(\\{2}\w+)\$?)(\\(\w[\w].*))+("

      ' Note, the file extensions must be PIPE delimited in the Reg Exp, but the web.config uses commas
      regEx &= allowableTypes.Replace(",", "|") & ")$"
      Return regEx
  End Function

IE 6.0 Hack - Float Issue

I ran into a strange browser compatibility issue when displaying a GridView.  FireFox wanted to float the grid off the screen to the right until I added Align="Left" to the GridView, but IE reacted by floating the grid behind the master page template so the content got truncated.  I ended up adding an IE hack to the CSS by placing “* html” before the class:

* html .ReportGrid {float:none;}

 

Oracle PL/SQL Split Function Boosts WHERE IN Clause Usability

Big thanks to Tech Republic for an article about creating a SPLIT user-defined function that accepts a delimited string and creates a table with N rows of data:

function Split
(
    p_list varchar2,
    p_del varchar2 := ','
) return split_tbl pipelined
is
    l_idx    pls_integer;
    l_list    varchar2(32767) := p_list;
    l_value    varchar2(32767);
begin
    loop
        l_idx := instr(l_list,p_del);
        if l_idx > 0 then
            pipe row(substr(l_list,1,l_idx-1));
            l_list := substr(l_list,l_idx+length(p_del));
        else
            pipe row(l_list);
            exit;
        end if;
    end loop;
    return;
end split;

 

And here’s how I used it to perform a “dynamic” query passing in a list of values:

select * 
from myTable
where IN_VARCHAR_LIST IS NULL OR 
    APP.AGENCY_ID IN(
        select column_value 
        from table(Split(IN_VARCHAR_LIST)))

Warning Users About Unsaved Changes

I was asked to implement a popup warning to alert users they were going to lose data if they navigated away from a form without saving. It turned out to be easier than I thought by using window.onbeforeunload

<script language="javascript">
   var doCheck = false;
   window.onbeforeunload = checkSave;

   function mustCheck() {
       doCheck = true;
   }

   function checkSave() {
       if (doCheck) {
           return "You have some changes that have not been saved. If you CONTINUE, your changes WILL BE LOST.";
       }
   }
</script>

And then adding a startup script in the FormView PreRender

ClientScript.RegisterStartupScript(Me.GetType, "mustCheck", "mustCheck();", True)

UPDATE - You have to add the following attribute to any buttons that do not need the warning (Cancel, Save, etc.):

OnClientClick="doCheck = false;"