public static TypeAdapterBuilder <TSource> EntityFromContext <TSource>(this TypeAdapterBuilder <TSource> builder, DbContext context)
{
const string dbKey = "Mapster.EFCore.db";
return(builder
.AddParameters(dbKey, context)
.ForkConfig(config =>
{
foreach (var entityType in context.Model.GetEntityTypes())
{
var type = entityType.ClrType;
var keys = entityType.FindPrimaryKey().Properties.Select(p => p.Name).ToArray();
var settings = config.When((srcType, destType, mapType) => destType == type);
settings.Settings.ConstructUsingFactory = arg =>
{
//var db = (DbContext)MapContext.Current.Parameters[DB_KEY];
//var set = db.Set<T>();
//return set.Find(src.id) ?? new T();
var src = Expression.Parameter(arg.SourceType);
var dest = arg.MapType == MapType.MapToTarget
? Expression.Parameter(arg.DestinationType)
: null;
var db = Expression.Variable(typeof(DbContext), "db");
var set = Expression.Variable(typeof(DbSet <>).MakeGenericType(arg.DestinationType), "set");
var current = typeof(MapContext).GetProperty(nameof(MapContext.Current), BindingFlags.Static | BindingFlags.Public);
var indexer = typeof(Dictionary <string, object>).GetProperties().First(item => item.GetIndexParameters().Length > 0);
var dbAssign = Expression.Assign(
db,
Expression.Convert(
Expression.Property(
Expression.Property(
Expression.Property(null, current),
nameof(MapContext.Parameters)),
indexer,
Expression.Constant(dbKey)),
typeof(DbContext)));
var setMethod = (from method in typeof(DbContext).GetMethods()
where method.Name == nameof(DbContext.Set) &&
method.IsGenericMethod
select method).First().MakeGenericMethod(arg.DestinationType);
var setAssign = Expression.Assign(set, Expression.Call(db, setMethod));
var getters = keys.Select(key => arg.DestinationType.GetProperty(key))
.Select(prop => new PropertyModel(prop))
.Select(model => arg.Settings.ValueAccessingStrategies
.Select(s => s(src, model, arg))
.FirstOrDefault(exp => exp != null))
.Where(exp => exp != null)
.Select(exp => Expression.Convert(exp, typeof(object)))
.ToArray();
if (getters.Length != keys.Length)
{
throw new InvalidOperationException($"Cannot get key for sourceType={arg.SourceType.Name}, destinationType={arg.DestinationType.Name}");
}
Expression find = Expression.Call(set, nameof(DbContext.Find), null,
Expression.NewArrayInit(typeof(object), getters));
if (arg.MapType == MapType.MapToTarget)
{
find = Expression.Coalesce(find, dest);
}
var ret = Expression.Coalesce(
find,
Expression.New(arg.DestinationType));
return Expression.Lambda(
Expression.Block(new[] { db, set }, dbAssign, setAssign, ret),
arg.MapType == MapType.MapToTarget ? new[] { src, dest } : new[] { src });
};
}
}, context.GetType().FullName));
}
public static TypeAdapterBuilder <TSource> CreateEntityFromContext <TSource>(this TypeAdapterBuilder <TSource> builder, IObjectContextAdapter context)
{
const string DB_KEY = "Mapster.EF6.db";
return(builder
.AddParameters(DB_KEY, context)
.ForkConfig(config =>
{
var oc = context.ObjectContext;
var entities = oc.MetadataWorkspace.GetItems <EntityType>(DataSpace.CSpace);
foreach (var entity in entities)
{
var type = (Type)entity.MetadataProperties.First(prop => prop.Name.EndsWith("ClrType")).Value;
var keys = entity.KeyMembers.Select(member => member.Name).ToArray();
var settings = config.When((srcType, destType, mapType) => destType == type);
settings.Settings.ConstructUsingFactory = arg =>
{
//var db = (DbContext)MapContext.Current.Parameters[DB_KEY];
//var set = db.Set<T>();
//return set.Find(src.id) ?? new T();
var src = Expression.Parameter(arg.SourceType);
var db = Expression.Variable(typeof(DbContext), "db");
var set = Expression.Variable(typeof(DbSet <>).MakeGenericType(arg.DestinationType), "set");
var current = typeof(MapContext).GetProperty(nameof(MapContext.Current), BindingFlags.Static | BindingFlags.Public);
var indexer = typeof(Dictionary <string, object>).GetProperties().First(item => item.GetIndexParameters().Length > 0);
var dbAssign = Expression.Assign(
db,
Expression.Convert(
Expression.Property(
Expression.Property(
Expression.Property(null, current),
nameof(MapContext.Parameters)),
indexer,
Expression.Constant(DB_KEY)),
typeof(DbContext)));
var setMethod = (from method in typeof(DbContext).GetMethods()
where method.Name == nameof(DbContext.Set) &&
method.IsGenericMethod
select method).First().MakeGenericMethod(arg.DestinationType);
var setAssign = Expression.Assign(set, Expression.Call(db, setMethod));
var getters = keys.Select(key => arg.DestinationType.GetProperty(key))
.Select(prop => new PropertyModel(prop))
.Select(model => arg.Settings.ValueAccessingStrategies
.Select(s => s(src, model, arg))
.FirstOrDefault(exp => exp != null))
.Where(exp => exp != null)
.Select(exp => Expression.Convert(exp, typeof(object)))
.ToArray();
if (getters.Length != keys.Length)
{
throw new InvalidOperationException($"Cannot get key for sourceType={arg.SourceType.Name}, destinationType={arg.DestinationType.Name}");
}
var ret = Expression.Coalesce(
Expression.Call(set, nameof(DbSet.Find), null, Expression.NewArrayInit(typeof(object), getters)),
Expression.New(arg.DestinationType));
return Expression.Lambda(
Expression.Block(new[] { db, set }, dbAssign, setAssign, ret),
src);
};
}
}, context.GetType().FullName));
}
