How can I change a value for a cell upon validation in a RadGrid using batch editing?

[Michael]

I have a Weight column in my RadGrid, which I'm using a CustomValidationFunction, which is working fine. It disallows invalid values.

But I want blank, 0 (or below) to be set automatically to the minimum value allowed, rather than making the user put it in manually. How can I accomplish this?

 

Here is the column I'm validating:

                                <telerik:GridTemplateColumn UniqueName="Weight" HeaderText="Weight" DataField="Weight" AllowFiltering="false">
                                    <ItemTemplate><%# Eval("Weight") %></ItemTemplate>
                                    <EditItemTemplate>
                                        <asp:TextBox ID="WeightAmt" runat="server" />
                                        <asp:CustomValidator runat="server" ID="WeightValidator" EnableClientScript="true" ControlToValidate="WeightAmt"
                                            ClientValidationFunction="WeightValidator" />
                                    </EditItemTemplate>
                                </telerik:GridTemplateColumn>
And here is the validation function as it currently stands:

        function WeightValidator(sender, args) {
            var thisWeight = parseInt(args.Value);
            if (thisWeight > maxWeight) {
                sender.textContent = "Weight may not be larger than " + maxWeight;
                args.IsValid = false;
                return;
            }
            if (thisWeight < 1) {
                thisWeight = minWeight;
                arguments[0].parentElement.parentElement.getElementsByTagName("input")[0].textContent = minWeight.toString();
            }
            if (thisWeight < minWeight) {
                sender.textContent = "Weight may not be smaller than " + minWeight;
                args.IsValid = false;
                return;
            }
            args.IsValid = true;
        }
Debug indicates the `arguments` statement sets the value, but this isn't actually tied to anything on the page, so it gets lost. The only place I see the cell value is in a hidden `div` (`style="display: none")` and I don't see any way of changing that.

In searching for a solution, I see it is recommended to edit the `innerHTML`, but that doesn't even contain the value I'm wanting to edit.

Is there a good way for validation to correct data errors that it can instead of just calling it invalid?

[Vasko]

Hi Michael,

The code that you provided deals with user input validation. If you want values to be modified automatically, this is not relevant. I  have some questions regarding the automation:

• How did you imagine changing blank or 0 values to 30 if you do not expect the user to do it?
• Why implement an additional automated solution within the Grid, If you could perform a single, one-line SQL query to update the values for every record at once.
  For example, a SQL query similar to the following:  

  "UPDATE [TableName] SET [Weight] = 30 WHERE [Weight] < 1 OR Weight = ''"

If you could provide further details about the requirements, we can better counsel you.

Kind regards,
Vasko
Progress Telerik

[Michael]

Thank you for your response. The urgency behind it is greatly diminished, as I have found additional issues incompatible with batch editing entirely.

But to answer your questions:

• I thought it was clear from the code, which you seem to see from your second point. If the user enters nothing or a negative number for the weight, then it automatically substitutes the minimum value, much like autocorrect on your phone for a "mistyped" word.
• It seems to me a cumbersome process to update all database records when it is only one record being changed. Furthermore, data already exists in the database, and I don't know if a null value is allowed for any such entries, but certainly my new UI will not allow future ones.

[Vasko]

Hello Micahel,

Thank you for the additional information.

Based on it, I managed to adjust the shared code snippet so that it achieves the desired behavior:  

<script>
    var minWeight = 30
    var maxWeight = 200 // Added for testing purposes

    function WeightValidator(sender, args) {
        var thisWeight = parseInt(args.Value);
        var inputElement = document.getElementById(sender.controltovalidate)  // This will be the ID of the currently clicked input eleemnt

        if (thisWeight > maxWeight) {
            sender.textContent = "Weight may not be larger than " + maxWeight;
            args.IsValid = false;
            return;
        }
        if (thisWeight < 1) {
            thisWeight = minWeight;

            inputElement.value = thisWeight  //Set the value to thisWeight (in my case 30)
        }
        if (thisWeight < minWeight) {
            sender.textContent = "Weight may not be smaller than " + minWeight;
            args.IsValid = false;
            return;
        }
        args.IsValid = true;
    }
</script>

Give the aforementioned method a try and see if it is of use to you.

Kind regards,
Vasko
Progress Telerik