Sharepoint Custom Filter Web Part - sharepoint

Question

I want to create a custom web part that has more than 1 filter web part and that can be connected to Report Viewer Web Part (Integrated Mode) at runtime/design time.
I searched a lot for this, but could not find a way to have single web part that is a provider to more than 1 filters.
Say for example -
My Report accepts 2 parameter Department and Region. 
I want to connect both parameters with single web part having two drop down (one for Department and one for Region)
Values from both the drop down should be passed to Department and Region
Report should be rendered in Report Viewer Web Part
Solution Tried so far
Create a web part that adds two custom drop down
Custom drop down class that implements from ITransformableFilterValues
Have 2 methods on the web pat each having ConnectionProvider attribute and return instance of drop down control
Problem:
Even though 2 connection option is shown on my custom filter web part only one can be added.
For example if I connect Filter1(custom web part) to Department then I am unable to connect it to Report Viewer web part again.
My web part have methods like this:
 
[ConnectionProvider("Departmet", "UniqueIDForDept", AllowsMultipleConnections = true)] 
public ITransformableFilterValues ReturnCity() 
{ 
return dropDownDepartment; // It implemets ITransformableFilterValues 
} 
[ConnectionProvider("Region", "UniqueIDForRegion", AllowsMultipleConnections = true)] 
public ITransformableFilterValues ReturnMyRegionB() 
{ 
return dropDownRegion; //It implemets ITransformableFilterValues 
}

Answer 1

I did something similar. This might help point you in the right direction. I used data in a form library to create a detailed report. I used reporting services and connected to sharepoint using web services. http://server/_vti_bin/Lists.asmx. The report parameter I used was the item ID or GUID. Then I configured my report viewer. On the form library I used JavaScript to override the context menu to add "View Report". On the report page I used a Query String filter to grab the item ID out of the url.

Answer 2

Not sure if you were able to fix your problem..
Actually I tried with AllowsMultipleConnections = true and it worked fine:
using System;
using System.Runtime.InteropServices;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Serialization;
using Microsoft.SharePoint;
using aspnetwebparts = System.Web.UI.WebControls.WebParts;
using Microsoft.Office.Server.Utilities;
using wsswebparts = Microsoft.SharePoint.WebPartPages;
using Microsoft.SharePoint.Portal.WebControls;
using System.Collections.ObjectModel;
using System.Collections.Generic;
using Microsoft.SharePoint.Utilities;
namespace FromMultiSource
{
[Guid("a0d068dd-9475-4055-a219-88513e173502")]
public class MultiSource : aspnetwebparts.WebPart
{
List<wsswebparts.IFilterValues> providers = new List<wsswebparts.IFilterValues>();
public MultiSource()
{
}
[aspnetwebparts.ConnectionConsumer("Multiple Source Consumer", "IFilterValues", AllowsMultipleConnections = true)]
public void SetConnectionInterface(wsswebparts.IFilterValues provider)
{
this.providers.Add(provider);
if (provider != null)
{
List<wsswebparts.ConsumerParameter> l = new List<wsswebparts.ConsumerParameter>();
l.Add (new wsswebparts.ConsumerParameter ("Value", wsswebparts.ConsumerParameterCapabilities.SupportsMultipleValues | Microsoft.SharePoint.WebPartPages.ConsumerParameterCapabilities.SupportsAllValue));
provider.SetConsumerParameters(new ReadOnlyCollection<wsswebparts.ConsumerParameter>(l));
}
}
protected override void CreateChildControls()
{
base.CreateChildControls();
// TODO: add custom rendering code here.
// Label label = new Label();
// label.Text = "Hello World";
// this.Controls.Add(label);
}
protected override void RenderContents(HtmlTextWriter writer)
{
base.RenderContents(writer);
this.EnsureChildControls();
foreach (wsswebparts.IFilterValues provider in this.providers)
{
if (provider != null)
{
string prop = provider.ParameterName;
ReadOnlyCollection<string> values = provider.ParameterValues;
if (prop != null && values != null)
{
writer.Write("<div>" + SPEncode.HtmlEncode(prop) + ":</div>");
foreach (string v in values)
{
if (v == null)
{
writer.Write("<div> <i>"(empty)"/null</i></div>");
}
else if (v.Length == 0)
{
writer.Write("<div> <i>empty string</i></div>");
}
else
{
writer.Write("<div> " + v + "</div>");
}
}
}
else
{
writer.Write("<div>No filter specified (all).</div>");
}
}
else
{
writer.Write("<div>Not connected.</div>");
}
writer.Write("<hr>");
}
}
}
}