Files
Umbraco-CMS/src/Umbraco.Core/Udi.cs
2017-09-23 10:08:18 +02:00

386 lines
16 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using Umbraco.Core.Deploy;
using Umbraco.Core.Composing;
namespace Umbraco.Core
{
/// <summary>
/// Represents an entity identifier.
/// </summary>
/// <remarks>An Udi can be fully qualified or "closed" eg umb://document/{guid} or "open" eg umb://document.</remarks>
[TypeConverter(typeof(UdiTypeConverter))]
public abstract class Udi : IComparable<Udi>
{
// notes - see U4-10409
// if this class is used during application pre-start it cannot scans the assemblies,
// this is addressed by lazily-scanning, with the following caveats:
// - parsing a root udi still requires a scan and therefore still breaks
// - parsing an invalid udi ("umb://should-be-guid/<not-a-guid>") corrupts KnowUdiTypes
private static volatile bool _scanned;
private static readonly object ScanLocker = new object();
private static ConcurrentDictionary<string, UdiType> _udiTypes;
private static readonly ConcurrentDictionary<string, Udi> RootUdis = new ConcurrentDictionary<string, Udi>();
internal readonly Uri UriValue; // internal for UdiRange
/// <summary>
/// Initializes a new instance of the Udi class.
/// </summary>
/// <param name="entityType">The entity type part of the identifier.</param>
/// <param name="stringValue">The string value of the identifier.</param>
protected Udi(string entityType, string stringValue)
{
EntityType = entityType;
UriValue = new Uri(stringValue);
}
/// <summary>
/// Initializes a new instance of the Udi class.
/// </summary>
/// <param name="uriValue">The uri value of the identifier.</param>
protected Udi(Uri uriValue)
{
EntityType = uriValue.Host;
UriValue = uriValue;
}
static Udi()
{
// initialize with known (built-in) Udi types
// we will add scanned types later on
_udiTypes = new ConcurrentDictionary<string, UdiType>(Constants.UdiEntityType.GetTypes());
}
// for tests, totally unsafe
internal static void ResetUdiTypes()
{
_udiTypes = new ConcurrentDictionary<string, UdiType>(Constants.UdiEntityType.GetTypes());
_scanned = false;
}
/// <summary>
/// Gets the entity type part of the identifier.
/// </summary>
public string EntityType { get; private set; }
public int CompareTo(Udi other)
{
return string.Compare(UriValue.ToString(), other.UriValue.ToString(), StringComparison.InvariantCultureIgnoreCase);
}
public override string ToString()
{
// UriValue is created in the ctor and is never null
// use AbsoluteUri here and not ToString else it's not encoded!
return UriValue.AbsoluteUri;
}
/// <summary>
/// Converts the string representation of an entity identifier into the equivalent Udi instance.
/// </summary>
/// <param name="s">The string to convert.</param>
/// <returns>An Udi instance that contains the value that was parsed.</returns>
public static Udi Parse(string s)
{
Udi udi;
ParseInternal(s, false, false, out udi);
return udi;
}
/// <summary>
/// Converts the string representation of an entity identifier into the equivalent Udi instance.
/// </summary>
/// <param name="s">The string to convert.</param>
/// <param name="knownTypes">A value indicating whether to only deal with known types.</param>
/// <returns>An Udi instance that contains the value that was parsed.</returns>
/// <remarks>
/// <para>If <paramref name="knownTypes"/> is <c>true</c>, and the string could not be parsed because
/// the entity type was not known, the method succeeds but sets <c>udi</c>to an
/// <see cref="UnknownTypeUdi"/> value.</para>
/// <para>If <paramref name="knownTypes"/> is <c>true</c>, assemblies are not scanned for types,
/// and therefore only builtin types may be known. Unless scanning already took place.</para>
/// </remarks>
public static Udi Parse(string s, bool knownTypes)
{
Udi udi;
ParseInternal(s, false, knownTypes, out udi);
return udi;
}
/// <summary>
/// Converts the string representation of an entity identifier into the equivalent Udi instance.
/// </summary>
/// <param name="s">The string to convert.</param>
/// <param name="udi">An Udi instance that contains the value that was parsed.</param>
/// <returns>A boolean value indicating whether the string could be parsed.</returns>
public static bool TryParse(string s, out Udi udi)
{
return ParseInternal(s, true, false, out udi);
}
/// <summary>
/// Converts the string representation of an entity identifier into the equivalent Udi instance.
/// </summary>
/// <param name="s">The string to convert.</param>
/// <param name="knownTypes">A value indicating whether to only deal with known types.</param>
/// <param name="udi">An Udi instance that contains the value that was parsed.</param>
/// <returns>A boolean value indicating whether the string could be parsed.</returns>
/// <remarks>
/// <para>If <paramref name="knownTypes"/> is <c>true</c>, and the string could not be parsed because
/// the entity type was not known, the method returns <c>false</c> but still sets <c>udi</c>
/// to an <see cref="UnknownTypeUdi"/> value.</para>
/// <para>If <paramref name="knownTypes"/> is <c>true</c>, assemblies are not scanned for types,
/// and therefore only builtin types may be known. Unless scanning already took place.</para>
/// </remarks>
public static bool TryParse(string s, bool knownTypes, out Udi udi)
{
return ParseInternal(s, true, knownTypes, out udi);
}
private static bool ParseInternal(string s, bool tryParse, bool knownTypes, out Udi udi)
{
if (knownTypes == false)
EnsureScanForUdiTypes();
udi = null;
Uri uri;
if (Uri.IsWellFormedUriString(s, UriKind.Absolute) == false
|| Uri.TryCreate(s, UriKind.Absolute, out uri) == false)
{
if (tryParse) return false;
throw new FormatException(string.Format("String \"{0}\" is not a valid udi.", s));
}
var entityType = uri.Host;
UdiType udiType;
if (_udiTypes.TryGetValue(entityType, out udiType) == false)
{
if (knownTypes)
{
// not knowing the type is not an error
// just return the unknown type udi
udi = UnknownTypeUdi.Instance;
return false;
}
if (tryParse) return false;
throw new FormatException(string.Format("Unknown entity type \"{0}\".", entityType));
}
var path = uri.AbsolutePath.TrimStart('/');
if (udiType == UdiType.GuidUdi)
{
if (path == string.Empty)
{
udi = GetRootUdi(uri.Host);
return true;
}
Guid guid;
if (Guid.TryParse(path, out guid) == false)
{
if (tryParse) return false;
throw new FormatException(string.Format("String \"{0}\" is not a valid udi.", s));
}
udi = new GuidUdi(uri.Host, guid);
return true;
}
if (udiType == UdiType.StringUdi)
{
udi = path == string.Empty ? GetRootUdi(uri.Host) : new StringUdi(uri.Host, Uri.UnescapeDataString(path));
return true;
}
if (tryParse) return false;
throw new InvalidOperationException(string.Format("Invalid udi type \"{0}\".", udiType));
}
private static Udi GetRootUdi(string entityType)
{
EnsureScanForUdiTypes();
return RootUdis.GetOrAdd(entityType, x =>
{
UdiType udiType;
if (_udiTypes.TryGetValue(x, out udiType) == false)
throw new ArgumentException(string.Format("Unknown entity type \"{0}\".", entityType));
return udiType == UdiType.StringUdi
? (Udi)new StringUdi(entityType, string.Empty)
: new GuidUdi(entityType, Guid.Empty);
});
}
/// <summary>
/// When required scan assemblies for known UDI types based on <see cref="IServiceConnector"/> instances
/// </summary>
/// <remarks>
/// This is only required when needing to resolve root udis
/// </remarks>
private static void EnsureScanForUdiTypes()
{
if (_scanned) return;
lock (ScanLocker)
{
// Scan for unknown UDI types
// there is no way we can get the "registered" service connectors, as registration
// happens in Deploy, not in Core, and the Udi class belongs to Core - therefore, we
// just pick every service connectors - just making sure that not two of them
// would register the same entity type, with different udi types (would not make
// much sense anyways).
var connectors = Current.TypeLoader.GetTypes<IServiceConnector>();
var result = new Dictionary<string, UdiType>();
foreach (var connector in connectors)
{
var attrs = connector.GetCustomAttributes<UdiDefinitionAttribute>(false);
foreach (var attr in attrs)
{
UdiType udiType;
if (result.TryGetValue(attr.EntityType, out udiType) && udiType != attr.UdiType)
throw new Exception(string.Format("Entity type \"{0}\" is declared by more than one IServiceConnector, with different UdiTypes.", attr.EntityType));
result[attr.EntityType] = attr.UdiType;
}
}
// merge these into the known list
foreach (var item in result)
_udiTypes.TryAdd(item.Key, item.Value);
_scanned = true;
}
}
/// <summary>
/// Creates a root Udi for an entity type.
/// </summary>
/// <param name="entityType">The entity type.</param>
/// <returns>The root Udi for the entity type.</returns>
public static Udi Create(string entityType)
{
return GetRootUdi(entityType);
}
/// <summary>
/// Creates a string Udi.
/// </summary>
/// <param name="entityType">The entity type.</param>
/// <param name="id">The identifier.</param>
/// <returns>The string Udi for the entity type and identifier.</returns>
public static Udi Create(string entityType, string id)
{
UdiType udiType;
if (_udiTypes.TryGetValue(entityType, out udiType) == false)
throw new ArgumentException(string.Format("Unknown entity type \"{0}\".", entityType), "entityType");
if (string.IsNullOrWhiteSpace(id))
throw new ArgumentException("Value cannot be null or whitespace.", "id");
if (udiType != UdiType.StringUdi)
throw new InvalidOperationException(string.Format("Entity type \"{0}\" does not have string udis.", entityType));
return new StringUdi(entityType, id);
}
/// <summary>
/// Creates a Guid Udi.
/// </summary>
/// <param name="entityType">The entity type.</param>
/// <param name="id">The identifier.</param>
/// <returns>The Guid Udi for the entity type and identifier.</returns>
public static Udi Create(string entityType, Guid id)
{
UdiType udiType;
if (_udiTypes.TryGetValue(entityType, out udiType) == false)
throw new ArgumentException(string.Format("Unknown entity type \"{0}\".", entityType), "entityType");
if (udiType != UdiType.GuidUdi)
throw new InvalidOperationException(string.Format("Entity type \"{0}\" does not have guid udis.", entityType));
if (id == default(Guid))
throw new ArgumentException("Cannot be an empty guid.", "id");
return new GuidUdi(entityType, id);
}
internal static Udi Create(Uri uri)
{
// if it's a know type go fast and use ctors
// else fallback to parsing the string (and guess the type)
UdiType udiType;
if (_udiTypes.TryGetValue(uri.Host, out udiType) == false)
throw new ArgumentException(string.Format("Unknown entity type \"{0}\".", uri.Host), "uri");
if (udiType == UdiType.GuidUdi)
return new GuidUdi(uri);
if (udiType == UdiType.GuidUdi)
return new StringUdi(uri);
throw new ArgumentException(string.Format("Uri \"{0}\" is not a valid udi.", uri));
}
public void EnsureType(params string[] validTypes)
{
if (validTypes.Contains(EntityType) == false)
throw new Exception(string.Format("Unexpected entity type \"{0}\".", EntityType));
}
/// <summary>
/// Gets a value indicating whether this Udi is a root Udi.
/// </summary>
/// <remarks>A root Udi points to the "root of all things" for a given entity type, e.g. the content tree root.</remarks>
public abstract bool IsRoot { get; }
/// <summary>
/// Ensures that this Udi is not a root Udi.
/// </summary>
/// <returns>This Udi.</returns>
/// <exception cref="Exception">When this Udi is a Root Udi.</exception>
public Udi EnsureNotRoot()
{
if (IsRoot) throw new Exception("Root Udi.");
return this;
}
public override bool Equals(object obj)
{
var other = obj as Udi;
return other != null && GetType() == other.GetType() && UriValue == other.UriValue;
}
public override int GetHashCode()
{
return UriValue.GetHashCode();
}
public static bool operator ==(Udi udi1, Udi udi2)
{
if (ReferenceEquals(udi1, udi2)) return true;
if ((object)udi1 == null || (object)udi2 == null) return false;
return udi1.Equals(udi2);
}
public static bool operator !=(Udi udi1, Udi udi2)
{
return (udi1 == udi2) == false;
}
private class UnknownTypeUdi : Udi
{
private UnknownTypeUdi()
: base("unknown", "umb://unknown/")
{ }
public static readonly UnknownTypeUdi Instance = new UnknownTypeUdi();
public override bool IsRoot
{
get { return false; }
}
}
}
}