Composite pattern
De Banane Atomic
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Description
- Compose objects into tree structures to represent part-whole hierarchies.
Composite lets clients treat individual objects and compositions of objects uniformly
Exemple
| IComponent.cs |
public interface IComponent
{
string Name { get; set; }
void Add(IComponent component);
void Remove(IComponent component);
string Display(int depth);
IComponent Find(string name);
void AddSuffix(string suffix);
}
|
| User.cs |
public class User : IComponent
{
public string Name { get; set; }
public User(string name)
{
this.Name = name;
}
public void Add(IComponent component)
{
throw new NotSupportedException("Cannot add a component to a user.");
}
public void Remove(IComponent component)
{
}
public string Display(int depth) => $"{new String('-', depth)} {Name}\n";
public IComponent Find(string name) => name.Equals(this.Name) ? this : null;
public void AddSuffix(string suffix)
{
Name += suffix;
}
}
|
| UsersGroup.cs |
public class UsersGroup : IComponent
{
public string Name { get; set; }
ICollection<IComponent> components;
public UsersGroup(string name)
{
this.components = new List<IComponent>();
this.Name = name;
}
public void Add(IComponent component)
{
components.Add(component);
}
public void Remove(IComponent componentToRemove)
{
if (!components.Remove(componentToRemove))
{
foreach (var component in components)
{
component.Remove(componentToRemove);
}
}
}
public string Display(int depth)
{
var stringBuilder = new StringBuilder();
stringBuilder.AppendLine($"{new String('-', depth)} {Name}");
foreach (var component in components)
{
stringBuilder.Append(component.Display(depth + 1));
}
return stringBuilder.ToString();
}
public IComponent Find(string name)
{
if (name.Equals(this.Name))
return this;
foreach (var component in components)
{
var matchingComponent = component.Find(name);
if (matchingComponent != null)
return matchingComponent;
}
return null;
}
public void AddSuffix(string suffix)
{
Name += suffix;
foreach (var component in components)
{
component.AddSuffix(suffix);
}
}
}
|
|
var group1 = new UsersGroup("Group1");
var user1 = new User("Nicolas");
group1.Add(user1);
var user2 = new User("Guillaume");
group1.Add(user2);
var group2 = new UsersGroup("Group2");
var user3 = new User("Paul");
group2.Add(user3);
var user4 = new User("Marie");
group2.Add(user4);
var group = new UsersGroup("Group");
group.Add(group1);
group.Add(group2);
var user5 = new User("Jean");
group.Add(user5);
group.AddSuffix("!");
group.Remove(group.Find("Guillaume"));
group.Remove(group.Find("Group2"));
Console.WriteLine(group.Display(1));
|
