Use type as comboBox with data from table

In this article we will improve the ProdID type, to show data from the Products table, when we use it in combo box.

First we will create a new type "ProductID":

This is the code for the new type:

using System;
using System.Collections.Generic;
using System.Text;
using Firefly.Box;
using ENV.Data;

namespace Northwind.Types
{
    public class ProductID : NumberColumn
    {
        public ProductID() : base("ProductID", "N10")
        {
        }
    }
} 

Now we will use it in the Order_Details table definition:

using Firefly.Box;
using ENV.Data;
namespace Northwind.Models
{
    /// <summary>Order_Details(E#3)</summary>
    public class Order_Details : Entity 
    {
        #region Columns
        [PrimaryKey]
        public readonly Types.OrderID OrderID = new Types.OrderID { Caption = "OrderID", Name = "OrderID" };
        [PrimaryKey]
-       public readonly NumberColumn ProductID = new NumberColumn("ProductID", "N10");
        public readonly Types.ProductID ProductID = new Types.ProductID();
        public readonly NumberColumn UnitPrice = new NumberColumn("UnitPrice", "10.3");
        public readonly NumberColumn Quantity = new NumberColumn("Quantity", "N5");
        public readonly NumberColumn Discount = new NumberColumn("Discount", "5.2");
        #endregion
        #region Indexes
        /// <summary>PK_Order_Details (#1)</summary>
        public readonly Index SortByPK_Order_Details = new Index { Caption = "PK_Order_Details", Name = "PK_Order_Details", AutoCreate = true, Unique = true };
        /// <summary>OrderID (#2)</summary>
        public readonly Index SortByOrderID = new Index { Caption = "OrderID", Name = "OrderID", AutoCreate = true };
        /// <summary>ProductID (#3)</summary>
        public readonly Index SortByProductID = new Index { Caption = "ProductID", Name = "ProductID", AutoCreate = true };
        #endregion
        public Order_Details() : base("dbo.[Order Details]", "Order_Details", Shared.DataSources.Northwind)
        {
            Cached = false;
            InitializeIndexes();
        }
        void InitializeIndexes()
        {
            SortByPK_Order_Details.Add(OrderID, ProductID);
            SortByOrderID.Add(OrderID);
            SortByProductID.Add(ProductID);
        }
    }
} 

Next we need to add some new functionality to our combobox :

We will start with adding an interface

namespace Northwind.Shared.Theme.Controls
{
    public partial class ComboBox : ENV.UI.ComboBox 
    {
        /// <summary>ComboBox</summary>
        public ComboBox()
        {
            if (!DesignMode)
            	FixedBackColorInNonFlatStyles = ENV.UserSettings.FixedBackColorInNonFlatStyles;
            InitializeComponent();
        }
    }
    public interface ICanConfigureCombo
    {
        void Configure(ComboBox c);
    }
} 

And now we will add the option to configure the combox using our new interface :

namespace Northwind.Shared.Theme.Controls
{
    public partial class ComboBox : ENV.UI.ComboBox 
    {
        /// <summary>ComboBox</summary>
        public ComboBox()
        {
            if (!DesignMode)
            	FixedBackColorInNonFlatStyles = ENV.UserSettings.FixedBackColorInNonFlatStyles;
            InitializeComponent();
        }
    }
    protected override void OnLoad()
    {
       if (Data != null)
       {
         var c = Data.Column as ICanConfigureCombo;
         if (c != null)
            {
                c.Configure(this);
            }
        }
            base.OnLoad();
        }
    }
    public interface ICanConfigureCombo {
        void Configure(ComboBox c);
    }
} 

Now we implement the ComboBox "ICanConfigureCombo" interface in the "ProductId" type:

using System;
using System.Collections.Generic;
using System.Text;
using Firefly.Box;
using ENV.Data;
using Northwind.Shared.Theme.Controls;

namespace Northwind.Types
{
-   public class ProductID : NumberColumn
    public class ProductID : NumberColumn , Shared.Theme.Controls.ICanConfigureCombo
    {
        public ProductID() : base("ProductID", "N10")
        {
            ControlType = typeof(Shared.Theme.Controls.ComboBox);
        }

        public void Configure(ComboBox c)
        {
            throw new NotImplementedException();
        }
    }
} 

Now we will change the code from throwing NotImplementedException to some reasonable code, that will populate the combobox with values from the Products table.

using System;
using System.Collections.Generic;
using System.Text;
using Firefly.Box;
using ENV.Data;
using Northwind.Shared.Theme.Controls;

namespace Northwind.Types
{
    public class ProductID : NumberColumn , Shared.Theme.Controls.ICanConfigureCombo
    {
        public ProductID() : base("ProductID", "N10")
        {
            ControlType = typeof(Shared.Theme.Controls.ComboBox);
        }

        public void Configure(ComboBox c)
        {
-           throw new NotImplementedException();
            var p = new Models.Products();
            c.ListSource = p;
            c.DisplayColumn = p.ProductName;
            c.ValueColumn = p.ProductID;
        }
    }
} 

At this point adding the ProductID column to a UIController will result in a regular column :

But if we change the TextBox to ComboBox you will get ComboBox that allow you to select from list of products:

You can also create a combo box builder class and enjoy it:

class ComboBuilder
{
    string comboValues = "", comboDisplayValues = "";
    public void PopulateComboBox(ENV.UI.ComboBox c)
    {

        c.Values = comboValues;
        c.DisplayValues = comboDisplayValues;

    }
    public void AddValue(Number key, Text value)
    {
        if (comboValues != "")
        {
            comboValues += ",";
            comboDisplayValues += ",";
        }
        comboValues += key.ToString().Trim();
        comboDisplayValues += value.Trim().Replace("-", "\\-");
    }
} 

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