Guys, I would vey appreciate if someone can help as soon as possible - I need to implement it right now.

Hi,

Hopefully this is not too late for you. But's here the pseudo code you can use:

var mc= DataContext.Current.MetaModel.MetaClasses["Address"];

using (MetaFieldBuilder builder = new MetaFieldBuilder(mc))

{

 builder.CreateText("NewField", "{Customer:Address_mf_NewField}", true, 64, false);

builder.SaveChanges();

}

Regards.

/Q

Hi Quan Mai!

Thank you for the answer! Yes, you are still in time.

Could you help me to initialize module manifest also please?

I am trying to add the field on application start event in my .NET MVC application like this:

private static void AddMetaFieldsToOrderAddressClassIfNeeded()
{
//init context
var connectionString = ConfigurationManager.ConnectionStrings["EcfSqlConnection"].ConnectionString;
DataContext.Current = new DataContext(connectionString);

//get metaclass
var mc = DataContext.Current.MetaModel.MetaClasses[CustomerAddress.ClassName /*metaclass name*/];

//TODO: check that field doesn't already exist
var changeTrackingManifest = new ModuleManifest() { }; //ModuleManifest.Load(path-???)
ModuleManager.Activate(mc, changeTrackingManifest);
using (var builder = new MetaFieldBuilder(mc))
{
builder.CreateText("Address_AddressCompanyName", "{Customer:Customer:Address_mf_Address_AddressCompanyName}", true, 100, false);
builder.SaveChanges();
}
}

But now it throws exception:

Module is not installed
Parameter name: manifest

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.ArgumentException: Module is not installed
Parameter name: manifest

on ModuleManager.Activate(mc, changeTrackingManifest);

Initialized changeTrackingManifest by this code:

var changeTrackingManifest = ChangeTrackingManager.CreateModuleManifest();

looks like it works.

Quan Mai, could yolu please comment why do I need to write this code:

var changeTrackingManifest = ChangeTrackingManager.CreateModuleManifest();
if (!ModuleManager.IsModuleActivated(mc, changeTrackingManifest))
{
ModuleManager.Activate(mc, changeTrackingManifest);
}

and do I need to deactivate the module after addition of the metafield?

Also sometimes I got exception "Module has been already activated.", but I added check:

//prepare
var changeTrackingManifest = ChangeTrackingManager.CreateModuleManifest();
if (!ModuleManager.IsModuleActivated(mc, changeTrackingManifest))
{
ModuleManager.Activate(mc, changeTrackingManifest);
}

Is it correct?

I guess you could make a shortcut and skip the ChangeTrackingManager, and instead check the field for existance directly on the metaclass? That's how we do it at least ;)

Anatoli Miazhenny : No, you can remove that line related to ModuleManager, I made a mistake when copy the code - I don't think it's necessary here. 

Regards.

/Q

Thank you guys, the issue is finally resolved.

The final version :)

private static void AddTextFieldToMetaclassAlt(string metaClassName, string fieldName, bool isNullable, int maxLength, bool isUnique)
{
//init context
if (DataContext.Current == null)
{
var connectionString = ConfigurationManager.ConnectionStrings["EcfSqlConnection"].ConnectionString;
DataContext.Current = new DataContext(connectionString);
}

//get metaclass
var mc = DataContext.Current.MetaModel.MetaClasses[metaClassName];

//check that field doesn't already exist
if (!mc.Fields.Contains(fieldName))
{
//add field
using (var builder = new MetaFieldBuilder(mc))
{
builder.CreateText(fieldName, string.Format("{{Customer:Customer:Address_mf_{0}}}", fieldName), isNullable, maxLength, isUnique);
builder.SaveChanges();
}
}
}

And the method call:

AddTextFieldToMetaclassAlt(CustomerAddress.ClassName /*metaclass name*/, "CustomerAddress_AddressCompanyName", true, 100, false);

Added this stuff to Global.asax.cs.