Save filter expression text

Environment

Product

RadFilter for ASP.NET AJAX

Description

Sometimes, one might want to save the filter expressions (the text that comes from the filter after the ExpressionPreviewPosition property has been set) for a specific use.

Solution

You can save the filter expression by using the ItemCommand event and getting the corresponding FieldName, FilterExpression, and Value properties.

<telerik:radfilter runat="server" id="RadFilter1" filtercontainerid="RadGrid1"
    expressionpreviewposition="Bottom" onitemcommand="RadFilter1_ItemCommand" />

<asp:Label Text="" ID="Label1" runat="server" />

<telerik:radgrid runat="server" id="RadGrid1" autogeneratecolumns="false" width="600px" allowpaging="true" allowsorting="true" datasourceid="SqlDataSource1">
    <mastertableview>
        <columns>
            <telerik:gridboundcolumn datafield="OrderID" headertext="OrderID" datatype="System.Int32" />
            <telerik:gridboundcolumn datafield="ShipCity" headertext="ShipCity" />
            <telerik:gridboundcolumn datafield="ShipName" headertext="ShipName" />
        </columns>
    </mastertableview>
</telerik:radgrid>
<asp:SqlDataSource runat="server" ID="SqlDataSource1"
    ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
    SelectCommand="Select OrderID, ShipName, ShipCity FROM Orders"></asp:SqlDataSource>

protected void RadFilter1_ItemCommand(object sender, RadFilterCommandEventArgs e)
{
    RadFilter filter = (RadFilter)sender;

    if (e.CommandName == RadFilter.ApplyCommandName)
    {
        List<RadFilterExpressionItem> filterExpressionList = filter.GetAllExpressionItems();

        for (int i = 0; i < filterExpressionList.Count; i++)
        {
            RadFilterSingleExpressionItem filterExpression = filterExpressionList[i] as RadFilterSingleExpressionItem;
            string expressionGroup = (filterExpressionList[0] as RadFilterGroupExpressionItem).Expression.GroupOperation.ToString();

            if (filterExpression != null)
            {
                string fieldName = filterExpression.Expression.FieldName;
                string expression = filterExpression.Expression.FilterFunction.ToString();
                int value = ((RadFilterSingleValueExpression<int>)filterExpression.Expression).Value;

                string text = fieldName + " " +  expression + " " + value.ToString() + expressionGroup;
                Label1.Text += text;
            }
        }
    }
}