JSFiddle - React, Tailwind, and code Playground

HTML

<div id="example"></div>

JavaScript

/**
 * @jsx React.DOM
 */


var Friend = React.createClass({
   render: function () {
     return(
        <div className="friend">
            {this.props.name}
             <a href="" onClick={this.props.select(this.props.key)}>select</a>
         </div>)
      }
})


var FriendBox = React.createClass({
  render: function () {
     var allFriends = this.props.friends.map((function (f) {
         return(
            <Friend
                key = {f.id}
                name = {f.name}
                select = {this.props.select}
            />)
            }).bind(this))

            return (
                <div className="Friendbox">
                   <div className="addFriend">
                       <a href="" onClick={this.props.add} > Add a friend</a>
                   </div>
                    <div className="friendsContainer">
                       {allFriends}
                    </div>

                </div> )
          }
})


var MainFrame = React.createClass({

      componentWillMount: function () {
            this.setState({friends: [
                  {id: 1, name: "maria"},
                  {id: 2, name: "pepe"}
            ], groups: [
                  {id: 1, name: "kyte"}
            ], selected: [
                  {id: 1, name: "maria"}
            ]})
      },

      sendToFriendH: function (id) {
            var _state = this.state;
            alert("before change is" + JSON.stringify(_state))
            var selected = _state.friends.filter(function (obj) {
                  return (obj.id == id)
            });

            _state.selected.push(selected);
             alert("after is" + JSON.stringify(_state));
            return (this.setState(_state))

      },

      removeFriendH: function (id) {
            var _state = this.state
 
            _state.friends = _state.filter(function (obj) {
                  return !(obj.id == id)
            });
            this.setState(_state)

      },

      addFriendH: function () {
 ...