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copied!<p>Well, Petter solution is nice.</p> <p>Just to share my implementation I will answer my question again, I hope that can be usefull to someone. Please, rate and comment.</p> <pre class="lang-cs prettyprint-override"><code>public interface IRepository<T> { IEnumerable<T> GetAll(); IEnumerable<T> GetAll(object parentId); T GetByKey(object keyValue); void Insert(T entidade, bool autoPersist = true); void Update(T entidade, bool autoPersist = true); void Delete(T entidade, bool autoPersist = true); void Save(); } </code></pre> <p>And the base class for XML Repositories</p> <pre class="lang-cs prettyprint-override"><code>public abstract class XmlRepositoryBase<T> : IRepository<T> { public virtual XElement ParentElement { get; protected set; } protected XName ElementName { get; private set; } protected abstract Func<XElement, T> Selector { get; } #endregion protected XmlRepositoryBase(XName elementName) { ElementName = elementName; // clears the "cached" ParentElement to allow hot file changes XDocumentProvider.Default.CurrentDocumentChanged += (sender, eventArgs) => ParentElement = null; } #region protected abstract void SetXElementValue(T model, XElement element); protected abstract XElement CreateXElement(T model); protected abstract object GetEntityId(T entidade); #region IRepository<T> public T GetByKey(object keyValue) { // I intend to remove this magic string "Id" return XDocumentProvider.Default.GetDocument().Descendants(ElementName) .Where(e => e.Attribute("Id").Value == keyValue.ToString()) .Select(Selector) .FirstOrDefault(); } public IEnumerable<T> GetAll() { return ParentElement.Elements(ElementName).Select(Selector); } public virtual IEnumerable<T> GetAll(object parentId) { throw new InvalidOperationException("This entity doesn't contains a parent."); } public virtual void Insert(T entity, bool autoPersist = true) { ParentElement.Add(CreateXElement(entity)); if (autoPersist) Save(); } public virtual void Update(T entity, bool autoPersist= true) { // I intend to remove this magic string "Id" SetXElementValue( entity, ParentElement.Elements().FirstOrDefault(a => a.Attribute("Id").Value == GetEntityId(entity).ToString() )); if (persistir) Save(); } public virtual void Delete(T entity, bool autoPersist = true) { ParentElement.Elements().FirstOrDefault(a => a.Attribute("Id").Value == GetEntityId(entity).ToString()).Remove(); if (autoPersist) Save(); } public virtual void Save() { XDocumentProvider.Default.Save(); } #endregion #endregion } </code></pre> <p>And 2 more abstract classes, one to Independent entities and other to child entities. To avoid reading the Xml file every time, I've made a kind of cache control</p> <pre class="lang-cs prettyprint-override"><code>public abstract class EntityXmlRepository<T> : XmlRepositoryBase<T> { #region cache control private XElement _parentElement; private XName xName; protected EntityXmlRepository(XName entityName) : base(entityName) { } public override XElement ParentElement { get { // returns in memory element or get it from file return _parentElement ?? ( _parentElement = GetParentElement() ); } protected set { _parentElement = value; } } /// <summary> /// Gets the parent element for this node type /// </summary> protected abstract XElement GetParentElement(); #endregion } </code></pre> <p>Now the implementation for child types</p> <pre class="lang-cs prettyprint-override"><code>public abstract class ChildEntityXmlRepository<T> : XmlRepositoryBase<T> { private object _currentParentId; private object _lastParentId; private XElement _parentElement; public override XElement ParentElement { get { if (_parentElement == null) { _parentElement = GetParentElement(_currentParentId); _lastParentId = _currentParentId; } return _parentElement; } protected set { _parentElement = value; } } /// <summary> /// Defines wich parent entity is active /// when this property changes, the parent element field is nuled, forcing the parent element to be updated /// </summary> protected object CurrentParentId { get { return _currentParentId; } set { _currentParentId = value; if (value != _lastParentId) { _parentElement = null; } } } protected ChildEntityXmlRepository(XName entityName) : base(entityName){} protected abstract XElement GetParentElement(object parentId); protected abstract object GetParentId(T entity); public override IEnumerable<T> GetAll(object parentId) { CurrentParentId = parentId; return ParentElement.Elements(ElementName).Select(Selector); } public override void Insert(T entity, bool persistir = true) { CurrentParentId = GetParentId(entity); base.Insert(entity, persistir); } public override void Update(T entity, bool persistir = true) { CurrentParentId = GetParentId(entity); base.Update(entity, persistir); } public override void Delete(T entity, bool persistir = true) { CurrentParentId = GetParentId(entity); base.Delete(entity, persistir); } } </code></pre> <p><strong>Now, a real world implementation</strong></p> <pre class="lang-cs prettyprint-override"><code>public class RepositorioAgendamento : EntityXmlRepository<Agendamento>, IRepositorioAgendamento { protected override Func<XElement, Agendamento> Selector { get { return x => new Agendamento() { Id = x.Attribute("Id").GetGuid(), Descricao = x.Attribute("Descricao").Value, TipoAgendamento = x.Attribute("TipoAgendamento").GetByte(), Dias = x.Attribute("Dias").GetByte(), Data = x.Attribute("Data").GetDateTime(), Ativo = x.Attribute("Ativo").GetBoolean(), }; } } protected override XElement CreateXElement(Agendamento agendamento) { agendamento.Id = Guid.NewGuid(); return new XElement(ElementName, new XAttribute("Id", agendamento.Id), new XAttribute("Descricao", agendamento.Descricao), new XAttribute("TipoAgendamento", agendamento.TipoAgendamento), new XAttribute("Dias", agendamento.Dias), new XAttribute("Data", agendamento.Data), new XAttribute("Ativo", agendamento.Ativo), new XElement(XmlNames.GruposBackup), new XElement(XmlNames.Credenciais) ); } protected override void SetXElementValue(Agendamento modelo, XElement elemento) { elemento.Attribute("Descricao").SetValue(modelo.Descricao); elemento.Attribute("TipoAgendamento").SetValue(modelo.TipoAgendamento); elemento.Attribute("Dias").SetValue(modelo.Dias); elemento.Attribute("Data").SetValue(modelo.Data); elemento.Attribute("Ativo").SetValue(modelo.Ativo); } public RepositorioAgendamento() : base(XmlNames.Agendamento) { } protected override XElement GetParentElement() { return XDocumentProvider.Default.GetDocument().Elements(XmlNames.Agendamentos).First(); } protected override object GetEntityId(Agendamento entidade) { return entidade.Id; } public IEnumerable<Agendamento> ObterAtivos() { return ParentElement.Elements() .Where(e => e.Attribute("Ativo").GetBoolean()) .Select(Selector); } } </code></pre> <p>And now, the XDocumentProvider. Its function is to abstract the access to the xml file and unify to all repositories what XDocument is the data context. <strong>This can be named UnitOfWork</strong>?</p> <pre class="lang-cs prettyprint-override"><code>public abstract class XDocumentProvider { // not thread safe yet private static bool pendingChanges; private bool _documentLoadedFromFile; FileSystemWatcher fileWatcher; public static XDocumentProvider Default; public event EventHandler CurrentDocumentChanged; private XDocument _loadedDocument; public string FileName { get; set; } protected XDocumentProvider() { fileWatcher = new FileSystemWatcher(); fileWatcher.NotifyFilter = NotifyFilters.LastWrite; fileWatcher.Changed += fileWatcher_Changed; } void fileWatcher_Changed(object sender, FileSystemEventArgs e) { if (_documentLoadedFromFile && !pendingChanges) { GetDocument(true); } } /// <summary> /// Returns an open XDocument or create a new document /// </summary> /// <returns></returns> public XDocument GetDocument(bool refresh = false) { if (refresh || _loadedDocument == null) { // we need to refactor it, but just to demonstrate how should work I will send this way ;P if (File.Exists(FileName)) { _loadedDocument = XDocument.Load(FileName); _documentLoadedFromFile = true; if (fileWatcher.Path != Environment.CurrentDirectory) { fileWatcher.Path = Environment.CurrentDirectory; fileWatcher.Filter = FileName; fileWatcher.EnableRaisingEvents = true; } } else { _loadedDocument = CreateNewDocument(); fileWatcher.EnableRaisingEvents = false; _documentLoadedFromFile = false; } if(CurrentDocumentChanged != null) CurrentDocumentChanged(this, EventArgs.Empty); } return _loadedDocument; } /// <summary> /// Creates a new XDocument with a determined schemma. /// </summary> public abstract XDocument CreateNewDocument(); public void Save() { if (_loadedDocument == null) throw new InvalidOperationException(); try { // tells the file watcher that he cannot raise the changed event, because his function is to capture external changes. pendingChanges = true; _loadedDocument.Save(FileName); } finally { pendingChanges = false; } } } </code></pre> <p>Then I can have many repositories for diferent entities adding pendent persistence actions in a single data context.</p> <p>I have made tests for my application that uses this repository using mocks and worked well.</p> <p>On my IoC configuration I have to set the Default for XDocumentProvider. If necessary, we can pass the XDocumentProvider throught constructor instead of this static "Default" property</p> <p>What do you think about my implementation?</p> <p>Thanks</p>

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