EpiServer for beginners: How to add custom fields to Order (eCommerce) programatically

Introduction

Some times ago, I had a post about adding a custom field to eCommerce from the user interface. That post got very popular and some folks like Khurram Khan and Steve C. mentioned that it is possible to add fields to eCommerce pragmatically. So in this post I will describe how to do it:

Steps
1- Create an initialization class

Create a class, inherit from IInitializableModule, add InitializableModule and ModuleDependency attribute to your class and you are almost there.

 [InitializableModule]

    [ModuleDependency(typeof(EPiServer.Commerce.Initialization.InitializationModule))]

    public class Initialization : IInitializableModule

* You will need to add "EPiServer.Commerce.Initialization" to have InitializationModule, "EPiServer.Framework" to have InitializableModuleAttribute and "Mediachase.MetaDataPlus.Configurator" to have MetaField methods but of course VS will add them for you when you write the names correctly

2-  Create the constructor and get the context

  public void Initialize(InitializationEngine context)

        {

        var mdContext = CatalogContext.MetaDataContext;

3- Use MetaField.Load to load your field from EPiServer.

        MetaField.Load(mdContext, name)

4- If the result was empty, create the field using MetaField.Create
The structure of the method is like this:

MetaField Create(MetaDataContext context, string metaNamespace, string name, string friendlyName, string description, MetaDataType dataType, int length, bool allowNulls, bool multiLanguageValue, bool allowSearch, bool isEncrypted);

* just to mention, length is the size of your data, so for example bool is 1, or DateTime is 8

5- Load the class that you want to add the field to it using  MetaClass.Load

  var mtClass = MetaClass.Load(mdContext, metaClassName);

6- Check if the meta field already exists in the meta class by checking its fields

  cls.MetaFields.Contains(field);

7- If the meta class doesn't have the class, add it using AddField

mtClass.AddField(field);

8- Smile :)

--------
It is very good idea to have simpler methods for adding fields and joining them to the meta class.

    private MetaField GetOrCreateMetaField(MetaDataContext mdContext, string metaDataNamespace, string name, MetaDataType type, int length, bool allowNulls, bool cultureSpecific)

        {

            var f = MetaField.Load(mdContext, name) ??

                    MetaField.Create(mdContext, metaDataNamespace, name, name, string.Empty, type, length, allowNulls, cultureSpecific, false, false);

            return f;

        }



        private void JoinField(MetaDataContext mdContext, MetaField field, string metaClassName)

        {

            var mtClass = MetaClass.Load(mdContext, metaClassName);



            if (MetaFieldIsNotConnected(field, mtClass ))

            {

                cls.AddField(field);

            }

        }

* And just to say: it is a good practice to have your strings inside enum classes. If you have a project, but you don't have any place for your enums and constants, you have to reconsider some of the stuff in your code :)

The whole code look like this:

 [InitializableModule]

    [ModuleDependency(typeof(EPiServer.Commerce.Initialization.InitializationModule))]

    public class Initialization : IInitializableModule

    {

  public void Initialize(InitializationEngine context)

        {



            MetaDataContext mdContext = CatalogContext.MetaDataContext;



            var myField = GetOrCreateMetaField(mdContext, Constants.Metadata.Namespace.Order,

          Extensions.PurchaseOrderExtensions.myFieldName, MetaDataType.DateTime, 8, true, false);

            JoinField(mdContext, myField, Constants.Metadata.OrderForm.ClassName);

        }



      private MetaField GetOrCreateMetaField(MetaDataContext mdContext, string metaDataNamespace, string name, MetaDataType type, int length, bool allowNulls, bool cultureSpecific)

        {

            var f = MetaField.Load(mdContext, name) ??

                    MetaField.Create(mdContext, metaDataNamespace, name, name, string.Empty, type, length, allowNulls, cultureSpecific, false, false);

            return f;

        }



        private void JoinField(MetaDataContext mdContext, MetaField field, string metaClassName)

        {

            var mtClass = MetaClass.Load(mdContext, metaClassName);



            if (MetaFieldIsNotConnected(field, mtClass ))

            {

                cls.AddField(field);

            }

        }



        private static bool MetaFieldIsNotConnected(MetaField field, MetaClass mtClass )

        {

            return mtClass != null && !cls.MetaFields.Contains(field);

        }

}

A Sample in a project
You can look at Steves  CommerceStarterKit and to be more specific, this page :) 

Acknowledgment
My gratitude to Steve Celius  for sharing his code with us.

EpiServer for beginners: How to add custom fields to Order (eCommerce)

Introduction

One of the simplest things that any developer would want is to add some fields to Order table or in related ones. When dealing with content pages, it would be handled automatically using Code-First methodology. But in the eCommerce system you have to do some steps.

Example

When you are dealing with external systems, you will need to have their Id in your system and since it is related to your order, well it is not a good idea to put in somewhere else.
Also, you may want to add external fields like status or etc to your order.

Steps

steps in Ecommerce

1- Go to Commerce Manager> Administration >Meta fields> New Meta Field

2- Fill name and friendly name and choose type of your field. Then choose properties like search option as you need. just have in mind that changing allow null field would be hard.

In these 2 steps, you've created a field in your order. Now you have to assign it to any table that you need.
3-  Go to meta classes right under order systems and select the main table(element) that you want to add your field. For instance, I want to add my field to my order form.

4- Now select the related external table related to that element. For order from it is only one, but it differs from element to element.

5- Select your field and click "OK"

Steps in your code

We have our field in our DB now.It is very easy to use it in your code.

The easiest way is to write a code like this line for setting the field:

Code:

 order.OrderForms[0]["MyFieldsName"] = value;

And Like this one to Getting it (for strings):

Code:

var x=order.OrderForms[0]["MyFieldsName"].ToString();

But It is always good to have a class, that contains names and methods for handling fields and their names.
Use Constants to avoid writing wrong names. Also set and get all fields in the same class so you have them centralized and use those methods.

Code:

 private const string MyFieldName = "MyFieldName";

public static string GetMyField()
{
   return order.OrderForms[0][MyFieldName].ToString();        
}

Edit:

I wrote a post in here  describing how to add the field grammatically.