Business Classes to TableServiceEntity Mapping Using Automapper

Summary

The following illustrates a convenient method of setting up a map between business classes to the Azure Table Storage entities using Automapper.  

Special Requirements

For this example both Automapper and Azure Table Storage were used:

• Automapper 2.2.1
• Windows Azure Storage 2.0.6.0

Mapping Example

In this example, I am mapping a Customer class to a TableStorageEntity.  The TableStorageEntity, named CustomerEntity has the same properties so a map between the two objects is ideal as little logic will need to be written.
The customer business object is defined as:

public class  Customer
{
    public Guid Id { get; set; }
    public string  Name { get; set; }        
}    

And the customer entity is defined as:

public class  CustomerEntity : Microsoft.WindowsAzure.Storage.Table.DataServices.TableServiceEntity
 {
        public Guid Id { get; set; }
        public string  Name { get; set; }
}

For convenience, I have created a operator methods for converting between Customer and CustomerEntity implicitely (this is added to the CustomerEntity class):

public static  implicit operator  Contracts.Customer(CustomerEntity from)
{
    return AutoMapper.Mapper.Map<CustomerEntity, Contracts.Customer>(from);
}
 
public static  implicit operator  CustomerEntity(Contracts.Customer from)
{
    return AutoMapper.Mapper.Map<Contracts.Customer, CustomerEntity>(from);
}

To complete the mapping, Automapper needs to have the map created before the implicit conversion is performed.  I chose to do this in the constructor of my class performing the TableServiceContext updates:

AutoMapper.Mapper.CreateMap<Customer, ServiceEntities.CustomerEntity>()
               .ForMember(m => m.PartitionKey, s => s.UseValue(PARTITIONKEY))
               .ForMember(m => m.RowKey, s => s.MapFrom(g => g.Id));
 
AutoMapper.Mapper.CreateMap<ServiceEntities.CustomerEntity, Customer>();

The following is an example of how the Add could be performed:

protected void  Add(Customer customer)
{
    var account = CloudStorageAccount.Parse(ConfigurationManager.AppSettings["StorageAccountConnectionString"]);
    var tableClient = new  CloudTableClient(account.TableEndpoint, account.Credentials);
 
    var context = tableClient.GetTableServiceContext();
 
    context.AddObject("Customer", customer);
    context.SaveChanges();
}

For a complete sample, please see the Azure Storage Sample Datalayer Framework.