Enterprise Library - Repository (partie 3)

Enterprise Library - Repository (partie 3)

IV Repository 

Toujours avec Contact pour exemple

On crée une interface listant les méthodes qui devront être implémenté

public interface IContactRepository

    {

        List<Contact> GetAllContacts();

        List<Contact> GetContactsOfCategory(int categoryID);

        Contact GetContact(int contactID);

        int AddContact(Contact contact);

        int UpdateContact(Contact contact);

        int RemoveContact(int contactID);

    }

La classe hérite de Repository<TDomainObject> et implémente son interface

public class ContactRepository : Repository<Contact>,IContactRepository

    {

        public ContactRepository(string databaseName)

            : base(databaseName)

        {

        }

        public List<Contact> GetAllContacts()

        {

            ISelectionFactory<NullableIdentity> selectionFactory = new GetAllContactsSelectionFactory();

            try

            {

                NullableIdentity nullableIdentity = new NullableIdentity();

                return Find(selectionFactory, new ContactFactory(), nullableIdentity);

            }

            catch (SqlException ex)

            {

                HandleSqlException(ex, selectionFactory);

            }

            return new List<Contact>();

        }

        public List<Contact> GetContactsOfCategory(int contactCategoryID)

        {

            ISelectionFactory<int> selectionFactory = new GetContactsOfCategorySelectionFactory();

            try

            {

                return Find<int>(selectionFactory, new ContactFactory(), contactCategoryID);

            }

            catch (SqlException ex)

            {

                HandleSqlException(ex, selectionFactory);

            }

            return new List<Contact>();

        }

        public Contact GetContact(int contactID)

        {

            ISelectionFactory<int> selectionFactory = new GetContactSelectionFactory();

            try

            {

                return FindOne(selectionFactory, new ContactFactory(), contactID);

            }

            catch (SqlException ex)

            {

                HandleSqlException(ex, selectionFactory);

            }

            return new Contact();

        }

        public int AddContact(Contact contact)

        {

            IInsertFactory<Contact> insertFactory = new ContactInsertFactory();

            try

            {

                return Add(insertFactory, contact);

            }

            catch (SqlException ex)

            {

                HandleSqlException(ex, insertFactory);

            }

            return 0;

        }

        public int UpdateContact(Contact contact)

        {

            IUpdateFactory<Contact> updateFactory = new ContactUpdateFactory();

            try

            {

                return Update(updateFactory, contact);

            }

            catch (SqlException ex)

            {

                HandleSqlException(ex, updateFactory);

            }

            return 0;

        }

        public int RemoveContact(int contactID)

        {

            IDeleteFactory<int> deleteFactory = new ContactDeleteFactory();

            try

            {

                return Remove(deleteFactory, contactID);

            }

            catch (SqlException ex)

            {

                HandleSqlException(ex, deleteFactory);

            }

            return 0;

        }

        private void HandleSqlException(SqlException ex, IDbToBusinessEntityNameMapper mapper)

        {

            if (ex.Number == ErrorCodes.SqlUserRaisedError)

            {

                switch (ex.State)

                {

                    case ErrorCodes.ValidationError:

                        string[] messageParts = ex.Errors[0].Message.Split(':');

                        throw new RepositoryValidationException(

                            mapper.MapDbParameterToBusinessEntityProperty(messageParts[0]),

                            messageParts[1], ex);

                    case ErrorCodes.ConcurrencyViolationError:

                        throw new ConcurrencyViolationException(ex.Message, ex);

                }

            }

            throw new RepositoryFailureException(ex);

        }

    }

J’utilise une et une seule fabrique pour la création d’instances à partir d’un datareader

Exemple ici ContactFactory

internal class ContactFactory : IDomainObjectFactory<Contact>

    {

        public Contact Construct(System.Data.IDataReader reader)

        {

            Contact contact = new Contact();

            contact.ContactID = Convert.ToInt32(reader["ContactID"]);

            contact.ContactName = Convert.ToString(reader["ContactName"]);

            contact.ContactFirstName = Convert.ToString(reader["ContactFirstName"]);

            if (reader["ContactAge"] != DBNull.Value)

                contact.ContactAge = Convert.ToInt32(reader["ContactAge"]);

            contact.ContactCategoryID = Convert.ToInt32(reader["ContactCategoryID"]);

            return contact;

        }

    }

V Création d’une «classe façade » Repositories

Ici dans la couche BusinessLogic, c’est avec cette classe que la couche présentation dialoguera

public static class Repositories

    {

        private const string databaseName = "ContactDBConnectionString";

        private static IContactRepository contactRepository = new ContactRepository(databaseName);

        private static ICategoryRepository categoryRepository = new CategoryRepository(databaseName);

        public static IContactRepository Contacts

        {

            get { return contactRepository; }

        }

        public static ICategoryRepository Categories

        {

            get { return categoryRepository; }

        }

    }

VI Couche présentation

Le fichier de configuration peut être au plus simple :

<?xml version="1.0" encoding="utf-8" ?>

<configuration>

      <connectionStrings>

            <add name="ContactDBConnectionString"

                  connectionString="Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|ContactDB.mdf;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/>

      </connectionStrings>

</configuration>

Exemple de code

       private void button1_Click(object sender, EventArgs e)

        {

            List<Contact> contacts = Repositories.Contacts.GetAllContacts();

            dataGridView1.DataSource = contacts;

        }