Connecting two webparts in SharePoint

This tutorial describes the step to access data by connecting two different Web Parts in a SharePoint Site. In order to do so, three things should be kept in mind:

• Provider Web Part (that provides the data)

• Connection Interface (that provides the connection between two Web Parts)

• Consumer Web Part ( that accepts the data)

But before we go further, one should be aware of how to create and deploy a web part.

Following are the steps :

Creating a Connection Interface

In this step, we create an interface say ‘CommunicationInterface’.  

In this interface, we define a property ‘ parameter1’ for  providing data.  The no. of properties depends on the no. of parameter to be passed.

//Code Part

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace CommunicationInterface

{

    public interface ICommunicationInterface

    {

        string parameter1 { get; }

    }

}

Once this interface is created, compile it and add its DLL to the Global Assembly Cache (C:\Windows\Assembly) in your  system.

Creating a Provider Web Part

The second step is to create a Provider Web Part to pass the data to the interface.

Create a web part and name it say ‘WP_Provider’.  Add reference of the earlier created ‘CommunicationInterface’ DLL. 

Once the reference is added,  implement the ‘ICommunicationInterface’ to ‘WP_Provider’ class.

Then the connection provider property is added and the reference to the communication Interface is returned.

Implement the property defined in the interface.

//Code Part

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 Microsoft.SharePoint.WebControls;

using Microsoft.SharePoint.WebPartPages;

using CommunicationInterface;

namespace WP_Provider

{

   

   public class 
   WP_Provider: Microsoft.SharePoint.WebPartPages.WebPart,ICommunicationInterface

    
   {

        Label nm;

        TextBox tbname;

        Button btn=new Button();

       

        RadioButtonList rb = new RadioButtonList();

       

      // Provides connection provider property for the parameters

      [ConnectionProvider("Parameter1 Provider",

                    "Parameter1 Provider")]

        public ICommunicationInterface ConnectionInterface()

        {

         // this returns a reference to the communication interface

            return this;

        }

        protected string _parameter1 = "";

        // Property defined in Interface is implemented

        public string parameter1

        {

            get { return _parameter1; }

        }

       

       

        public WP_Provider()

        {

       

        }

        protected override void CreateChildControls()

        {

            base.CreateChildControls();

            //Accessing a particular list items

            SPSite mysitecol = SPContext.Current.Site;

            SPWeb mysite = SPContext.Current.Web;

            SPList mylist = mysite.Lists["UpdateList"];

            SPListItemCollection itemcol = mylist.Items;

           

            foreach (SPListItem itm in itemcol)

            {

                string nm = itm["Company_Id"].ToString();

                rb.Items.Add(nm);

            }

            btn.Text = "Send";

            this.Controls.Add(rb);

            this.Controls.Add(btn);

            btn.Click += new EventHandler(btn_Click);

        }

   public  void btn_Click(object sender, EventArgs e)

        {

            // set connection provider property with required textbox info.

           // this._parameter1 = tbname.Text;

            this._parameter1 = rb.SelectedItem.Text;

        }

    }

}

After completing the code, compile and add the DLL in the Global Assembly Cache (C:\Windows\Assembly).

Create the corresponding ‘dwp’ file and add the SafeControl in the web.config of SharePoint Site.

Creating a Consumer Web Part

The third step is to create a Consumer  Web Part to pass the data to the interface.

Create a web part and name it say ‘WP_Consumer’.  Add reference of the earlier created ‘CommunicationInterface’ DLL. 

Then the connection Consumer property is added and the reference to the communication Interface is retrieved.

From this reference, the parameter that is passed from Provider Web Part is obtained.

//Code

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 Microsoft.SharePoint.WebControls;

using Microsoft.SharePoint.WebPartPages;

using CommunicationInterface;

namespace WP_Consumer

{

   

    public class WP_Consumer : Microsoft.SharePoint.WebPartPages.WebPart

    {

       //Label lblTitle;

       Label lblname=new Label();

      

    ///// the string info consumer from custom reciever   //

    ICommunicationInterface connectionInterface = null;

    // The consumer webpart  must define a method that

    // would accept the interface as an parameter

    // and must be decorated with ConnectionConsumer attribute     

    [ConnectionConsumer("Parameter1 Consumer",

                        "Parameter1 Consumer")]

    public void GetConnectionInterface(ICommunicationInterface

                                       _connectionInterface)

    {

        connectionInterface = _connectionInterface;

    }

    ///////////////////////////////////////////////////////// 

    public WP_Consumer()

    {

       

    }

        protected override void CreateChildControls()

        {

            base.CreateChildControls();

            

            this.Controls.Add(lblname);

           

        }

        protected override void OnPreRender(EventArgs e)

        {

            base.OnPreRender(e);

            if (connectionInterface != null)

            {

                lblname.Text = connectionInterface.parameter1 +

                " is recieved!";

               

             }

            else

            {

                lblname.Text = "nothing is recieved!";

            }

           

        }

     

          

     }

       

  }

}

After completing the code, compile and add the DLL in the Global Assembly Cache. (C:\Windows\Assembly)

Create the corresponding ‘dwp’ file and add the SafeControl in the web.config of SharePoint Site.