CONTOH KASUS REGISTRASI/TAMBAH USER

(A) BAGIAN CONTROLLER (LOGIC)
function tambah()
	 {
	 	$username = db_clean($this->input->post('user_username'));
	 	$nama = db_clean($this->input->post('user_nama'));
	  	$level = $this->input->post('id_level');

	  	$cek1 = $this->m_all->cek($username, $this->primary, $this->table);
	  	if ($cek1->num_rows() > 0)
	  	{
	  		$response = array('status'=>'gagal','pesan'=>'Username telah tersedia');
	  	}
	  	else
	  	{
	  		$info = array(
	  					'id_user'			=> date('Y-m-d H:i:s'),
	  					'user_username'		=> $username,
	  					'user_nama'			=> $nama,
	  					'user_level'		=> $level,
	  		);
	  		$this->m_all->simpan($info, $this->table);

	  		ob_start();
	  		$html = ob_get_contents();
	  		ob_end_clean();

	  		$response = array('status'=>'sukses','pesan'=>'Registrasi user berhasil', 'html'=>$html);
	  	}

	  	echo json_encode($response);
	 }

(B) BAGIAN VIEW
<div id="modal-id" class="modal fade">
	<div class="modal-dialog">
    	<div class="modal-content">
        	<div class="modal-header">
            	<button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        			<h4 class="modal-title">
        			<!-- Beri id "modal-title" untuk tag span pada judul modal -->
        				<span id="modal-title"></span>
        			</h4>
        	</div>
        	<div class="modal-body">
        	<!-- Beri id "pesan-error" untuk menampung pesan error -->

        		<!-- Beri id "form" untuk tag form -->
        			<form id="form-id" class="form-horizontal">
        			<!-- -- Beri id untuk masing-masing form input -->
        				<div class="form-group">
        					 <label>UserName</label>
                             <input type="text" class="form-control" data-inputmask="'mask' : '(+99) 999-9999-9999'" placeholder="No Mobile" id="user_username" name="user_username">
        				</div>
        				<div class="form-group">
        					<label>Nama</label>
        					<input type="text" class="form-control" id="user_nama" name="user_nama" placeholder="Nama User">
        				</div>
        				<div class="form-group">
        					<label>Level</label>
        					<?php echo form_dropdown("id_level",$level,"", 'id="id_level" class="form-control"')?>
        				</div>
        			</form>
       		</div>
       		<div class="modal-footer">
       			<div class="btn-group pull-right">
       		<!-- Beri id "btn-simpan" untuk tombol simpan nya -->
       				<button type="button" class="btn btn-default" id="btn-save">Simpan</button>
       		<!-- Beri id "btn-ubah" untuk tombol simpan nya -->
       				<button type="button" class="btn btn-default" data-dismiss="modal">Tutup</button>
       			</div>
       		</div>
       	</div>
    </div>
</div>

(C) BAGIAN MODEL
function cek($kode , $primary, $table, $cek1 = NULL, $cek2 = NULL, $cek3 = NULL){
        if ($table == 'user')
    	{
        	$this->db->trans_start();
    		$this->db->select('user.*, level.*');
        	$this->db->from('user');
        	$this->db->where('user_level != 1');
        	$this->db->where($primary,$kode);
        	$this->db->join('level', 'user.user_level = level.id_level', 'left');
        	$this->db->trans_complete();
    		if ($this->db->trans_status() === FALSE)
    		{
    			$this->db->trans_rollback();
    			return FALSE;
    		}
        	return $this->db->get();
        }
}

(D) DESIGN TABLE USER
CREATE TABLE `tb_user` (
  `id_user` timestamp NOT NULL ON UPDATE CURRENT_TIMESTAMP,
  `user_username` varchar(100) DEFAULT NULL,
  `user_nama` varchar(100) DEFAULT NULL,
  `user_level` int(4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

(E) SEDIKIT CODE JAVASCRIPT/AJAX
$(document).ready(function(){
	var btn_save = $("#btn-save");
	$(btn_save).on("click", function(e){
			if ($.trim($("#user_username").val()).length > 0)
			{
				if ($.trim($("#user_nama").val()).length > 0)
				{
					if ($("#id_level").val() > 0)
					{
						//if ($("#id_toko").val() > 0)
						//{

							var data = new FormData();

							data.append("user_username", $("#user_username").val().replace(/[^A-Z0-9]/ig, ""));
							data.append("user_nama", $("#user_nama").val());
							data.append("id_level", $("#id_level").val());
							//data.append("id_toko", $("#id_toko").val());

							$.ajax({
								url: "<?php echo site_url('register_user/tambah')?>",
								type: "POST",
								data: data,
				       			processData: false,
				       			contentType: false,
				       			dataType: "json",
				       			beforeSend: function(e) {
				       				if(e && e.overrideMimeType) {
				       					e.overrideMimeType("application/json;charset=UTF-8");
				       				}
				       			},
				       			success: function(respon){
				      				if(respon.status == "sukses"){
				      					alert(respon.pesan);
				      					location.href = location.pathname;
						   			}else{
					   		        	alert(respon.pesan);
				    	        	}
				    			},
				    			error: function (jqXHR, textStatus, errorThrown)
				    			{
				    				alert(jqXHR.responseText);
				    			}
				 			});
						//}
						//else alert("tentukan toko asal");
					}
					else alert("tentukan level user");
				}
				else alert("input nama user");
			}
			else alert("input username");
		});
});