Thursday, 22 May 2008

DynamicData - Limit the Filter Fields

Articles in this Series

Limit the Filter Fields

Below is the attribute and helper class.

using System;
using System.Linq;
using System.Web.DynamicData;

/// <summary>
/// attribute to suppress an MetaChildColumn or MetaParetnColumn in the 
/// filter repeater
/// </summary>
[AttributeUsage(AttributeTargets.Property, AllowMultiple = true)]
public class HideInFilterAttribute : System.Attribute
    // this property is required to work with "AllowMultiple = true" ref David Ebbo
    // As implemented, this identifier is merely the Type of the attribute. However, 
    // it is intended that the unique identifier be used to identify two 
    // attributes of the same type.
    public override object TypeId { get { return this; } }

    /// <summary>
    /// Constructor
    /// </summary>
    public HideInFilterAttribute()

/// <summary>
/// Permissions Attributes Helper Extension Methods
/// </summary>
public static class HideInFilterAttributesHelper
    public static Boolean ContainsHideInFilter(this MetaColumn column)
        // thanks to Marcin Dobosz for this really elegant code
        return column.Attributes.OfType<HideInFilterAttribute>().FirstOrDefault() != null;
Listing 1

Sample metadata

public partial class Order

public class OrderMetadata
    // entities
    public Object Employee { get; set; }
Listing 2

And in the code on the page (i.e. List.aspx.cs) an OnItemDataBound="FilterRepeater_ItemDataBound" is added to the FilterRepeater.

    onitemdatabound="FilterRepeater_ItemDataBound" >
Listing 3

In the OnItemDataBound method I check for the metadata using the helper method (which make the code more readable) and set the e.Item.Visible = false.

protected void FilterRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
    var column = e.Item.DataItem as MetaColumn;
    if (column != null)
        if (column.ContainsHideInFilter())
            e.Item.Visible = false;
Listing 4

Now just by adding metadata to any field (MetaForeignKeyColumn or MetaChildrenColumn), then that filter field can be hidden.


Anonymous said...

Hello, many thanks for your work. I have a question, how would I have to modify this code to hide the filters by role?

Thanks in advance.

Steve said...

Hi there Anonymous, e-mail me and I'll send you a sample that workes by roles.

Steve :)

Chelo said...

Hi Steve...
Could you send mee too?

Steve said...

Hi Chelo send me an e-mail and I'll sent it to you also.


Bob said...

Im using a DD4 site, I take it this was written for an different version. I'm getting the error

'System.Web.DynamicData.QueryableFilterRepeater' does not have a public property named 'OnItemDataBound'.

What do I need to change for this to work?

Steve said...

yes this was written for either DDv1 or the old future project, if you look at my Dynamic Data Extensions this has filter ordering etc.

Bob said...

I wish to disable the dropdown list for on of the foreign keys, I have this

public object Customer { get; set; }

But doesn't work, is what I'm doing ok?

Steve said...

Bob, this is too cumbersom to solve these issue just e-mail me direct.

P.S. always state which version of .Net + Service Pack you are running and version of Visual Studio if relavent.


samir jikadia said...

Hello Steve,

Please send us an application.
Email id:

Best Regards,

James Manning said...

In case anyone else runs across this post, in the 2012 bits for dynamic data there is now built-in support for this - specifically, you can add [Display(AutoGenerateFilter = false)] and it works great!

Steve said...

Hi James, this does not work with DD 4 or 4.5 as the filter system is completly different.


LA Guy said...

Hi Steve and James,

I have a .Net 4.5 Dyn Data project
and the AutoGenerateFilter parameter works to hide or show the Filter Dropdown.

//[Display(Name = "Site ID", Order = 8, AutoGenerateFilter=false )]
[Display(Name = "Site ID", Order = 8, AutoGenerateFilter = true)]
public Site Site { get; set; }

Thanks for all your hard work.

Best, LA Guy