[Solved] FilterExpression

[Gaurab]

In the FilterExpression, I noticed Telerik is using ")||(" instead of ")OR(".  Evidently this works, but I believe the recommendation is "OR".  I only bring this up because in many situations, the RadGrid1.MasterTableView.FilterExpression can be used directly as the WHERE clause is in a SQL Query.  SQL understands "OR", but not "||".

I'm using it for my where clause in my project to retrieve related data, so you might consider changing it just for me. :-)

In the meantime RadGrid1.MasterTableView.FilterExpression.Replace("||", "OR") is working well.

Thanks!

[Viktor Tachev]

Hello Jon,

The FilterExpression for the RadGrid use "OR" and "AND" operators. If you would like, you could check the difference when using various data sources in this article. I am afraid that the "||" operator is not used.

This said, would you elaborate more on the configuration that you have. What are the settings for the RadGrid? I would appreciate it if you could share your full markup with the code-behind so we could have better understanding of your scenario. Thank you in advance.


Regards,
Viktor Tachev
Telerik

 

 

[Gaurab]

In the OnNeedDataSource, if you check the FilterExpression, it is using "||".  I replaced it with "OR" as in the following:

var filter Expression = RadGrid1.MasterTableView.FilterExpression.Replace("||","OR");

Is this not the code that creates the filter?

public virtual string EvaluateFilterExpression(GridFilteringItem filteringItem)
{
    if (!this.SupportsFiltering())
    {
        return string.Empty;
    }

    TableCell cell = filteringItem[this.UniqueName];
    string filterValue = this.GetCurrentFilterValueFromControl(cell);

    if (this.ListOfFilterValues != null && this.ListOfFilterValues.Length > 0)
    {
        if (this.CurrentFilterFunction == GridKnownFunction.EqualTo)
        {
            GridFilterFunction filterFunc = new GridFilterFunction(this.CurrentFilterFunction);
            StringBuilder exprBuilder = new StringBuilder();
            exprBuilder.Append("(");
            exprBuilder.Append(filterFunc.GetFunctionString(this.GetFilterDataField(), this.ListOfFilterValues[0], this.DataType, filteringItem.OwnerTableView));
            for (int i = 1; i < this.ListOfFilterValues.Length; i++)
            {

                string filterPart = filterFunc.GetFunctionString(this.GetFilterDataField(), this.ListOfFilterValues[i], this.DataType, filteringItem.OwnerTableView);
                if (!string.IsNullOrEmpty(filterPart))
                {
                    exprBuilder.Append(")||(");
                    exprBuilder.Append(filterPart);
                }
            }
            exprBuilder.Append(")");
            return exprBuilder.ToString();
        }
        else if (this.CurrentFilterFunction == GridKnownFunction.NoFilter)
        {
            this.ListOfFilterValues = null;
        }
    }

    if (String.IsNullOrEmpty(filterValue) && !FunctionTakesNoArguments(this.CurrentFilterFunction))
    {
        return "";
    }
    else
    {
        GridFilterFunction filterFunc = new GridFilterFunction(this.CurrentFilterFunction);
        //Get DataType of colum
        return filterFunc.GetFunctionString(this.GetFilterDataField(), filterValue, this.DataType, filteringItem.OwnerTableView);
    }
}

Maybe I'm misunderstanding something...

[Gaurab]

To clarify, this is occurring when using a checkboxlist for a filter.

[Viktor Tachev]

Hi Jon,

Thank you for the clarification.

I am afraid that modifying the generated FilterExpression at this point would not be possible as it would introduce a breaking change.

If you would like to use it directly to query a database you could use the approach that you currently have implemented - replacing the "||" string with "OR".

Regards,
Viktor Tachev
Telerik

 

 

[Gaurab]

Sounds good.  I don't blame you for not changing it.  I had noticed it and I saw on the page you referred to that it showed using an "OR", but it was using "||".  So, I thought I'd bring it up in case you wanted to change it, or the documentation, in the future.

Thanks for your feedback.

[Vivek]

I am having a similar problem. I need to set ListOfFilterValues = Nothing for a GridBoundColumn. My code is as follows:

If TypeOf column Is GridBoundColumn Then
     Dim boundColumn As GridBoundColumn = TryCast(column, GridBoundColumn)
     boundColumn.FilterListOptions = GridFilterListOptions.AllowAllFilters
     DirectCast(column, Telerik.Web.UI.GridBoundColumn).ListOfFilterValues = Nothing

End If

However I am getting the error

Error 1 'Telerik.Web.UI.GridColumn.Protected Friend Property ListOfFilterValues As String()' is not accessible in this context because it is 'Protected Friend'. 

Any solution?

Thanks

[Viktor Tachev]

Hi Vivek,

If you would like to clear the filters that are applied in the RadGrid you could use an approach similar to the one below. It illustrates how you could clear the filters in the grid when a Button is clicked:

Protected Sub clrFilters_Click(ByVal sender As Object, ByVal e As EventArgs)
    For Each column As GridColumn In RadGrid1.MasterTableView.Columns
        column.CurrentFilterFunction = GridKnownFunction.NoFilter
        column.CurrentFilterValue = String.Empty
    Next
    RadGrid1.MasterTableView.FilterExpression = String.Empty
    RadGrid1.MasterTableView.Rebind()
End Sub

Regards,
Viktor Tachev
Telerik

 

 

[Vivek]

Hi Viktor,

Thanks for your reply. I tried your solution. It works
partially. I have explained my problem in the attached document. Please let me
know if you need any more clarification.

Attachment failed. So I have emailed the attachment. 

Thanks

 

Vivek Arkalgud

[Viktor Tachev]

Hi Vivek,

Would you send a formal support ticket and attach the files there? This would enable us to investigate the issue locally and look for its cause.

Regards,
Viktor Tachev
Telerik