public void three_level_in_a_hierarchy_with_anonymous_types()
{
Expression <Func <Blog, object> > expression = x => new { x.Admin.Address.State };
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(1);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Admin.Address.State");
}
public void using_the_select_method_for_collections_with_anonymous_types()
{
Expression <Func <Blog, object> > expression = x => new { Prop = x.Posts.Select(p => p.Comments) };
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(1);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Posts.Comments");
}
public void simple_expression_with_anonymous_types()
{
Expression <Func <Blog, object> > expression = x => new { x.Admin };
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(1);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Admin");
}
public void two_level_in_a_hierarchy()
{
Expression <Func <Blog, object> > expression = x => x.Admin.Address;
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(1);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Admin.Address");
}
public void using_the_select_method_for_sub_collections()
{
Expression <Func <Blog, object> > expression = x => x.Posts.SelectMany(p => p.Comments).Select(comment => comment.Member);
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(1);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Posts.Comments.Member");
}
public void should_support_multi_properties_using_the_select_method_for_sub_collections_with_anonymous_types()
{
Expression <Func <Blog, object> > expression = x => new { Prop = x.Name + x.Posts.SelectMany(p => p.Comments).Select(comment => comment.Member) };
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(2);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Name");
propertyPathVisitor.Properties.ElementAt(1).Should().Be("Posts.Comments.Member");
}
public void should_support_multi_properties_with_constants()
{
Expression <Func <Blog, object> > expression = x => "Name: " + x.Name + " " + x.Admin.Name;
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(2);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Name");
propertyPathVisitor.Properties.ElementAt(1).Should().Be("Admin.Name");
}
public void should_support_multi_properties_with_anonymous_types()
{
Expression <Func <Blog, object> > expression = x => new { Prop = x.Name != x.Admin.Name };
var propertyPathVisitor = new PropertyPathVisitor();
propertyPathVisitor.Visit(expression);
propertyPathVisitor.Properties.Should().HaveCount(2);
propertyPathVisitor.Properties.ElementAt(0).Should().Be("Name");
propertyPathVisitor.Properties.ElementAt(1).Should().Be("Admin.Name");
}
public static string Property <TItem, TValue>(Expression <Func <TItem, TValue> > propertyExpression)
{
var path = PropertyPathVisitor.GetPath(propertyExpression);
var memberInfo = path.Last();
if (!(memberInfo is PropertyInfo))
{
throw new ArgumentException("The expression is for a method", nameof(propertyExpression));
}
return(memberInfo.Name);
}
public static string Property <T>(Expression <Func <T> > propertyExpression, bool allowNestedProperty = false)
{
var path = PropertyPathVisitor.GetPath(propertyExpression);
if (path.Count > 1 && !allowNestedProperty)
{
throw new ArgumentException("Trying to get the name of a nested property: " + string.Join(".", path.Select(x => x.Name)));
}
var memberInfo = path.Last();
if (!(memberInfo is PropertyInfo))
{
throw new ArgumentException("The expression is for a method", nameof(propertyExpression));
}
return(memberInfo.Name);
}
public static IQueryable <TEntity> Include <TEntity>(this IQueryable <TEntity> source, Expression <Func <TEntity, object> > selector) where TEntity : class
{
string path = new PropertyPathVisitor().GetPropertyPath(selector);
return(source.Include(path));
//StringBuilder pathBuilder = new StringBuilder();
//MemberExpression pro = path.Body as MemberExpression;
//while (pro != null)
//{
// //如: x=> x.Customer.CustomerAddress
// //path.Body是CustomerAddress
// //CustomerAddress的Expression是Customer
// //Customer的Expression是x
// pathBuilder.Insert(0, "." + pro.Member.Name);
// pro = pro.Expression as MemberExpression;
//}
//return source.Include(pathBuilder.ToString(1, pathBuilder.Length - 1));
}
public void complex_expression_with_anonymous_types()
{
Expression <Func <Foo, object> > selector1 = foo => new
{
foo.Name,
foo.ImInAnEntity,
foo.Bars,
foo.UnitPrice,
foo.UnitsInStock
};
Expression <Func <Foo, object> > selector2 = foo => new
{
foo.Bar.Bee.Name,
foo.Bar.ImInAnEntity,
foo.Bar.Bee.UnitPrice
};
var visitor = new PropertyPathVisitor();
visitor.Visit(selector1);
visitor.Visit(selector2);
var properties = visitor.Properties;
properties.Should().HaveCount(8);
properties.Where(x => x.Contains('.')).Should().HaveCount(3);
properties.Where(x => !x.Contains('.')).Should().HaveCount(5);
var expected = new HashSet <string>
{
"Name", "ImInAnEntity", "Bars", "UnitPrice", "UnitsInStock",
"Bar.Bee.Name", "Bar.ImInAnEntity", "Bar.Bee.UnitPrice"
};
for (var index = 0; index < properties.Count; index++)
{
properties.ElementAt(index).Should().Be(expected.ElementAt(index));
}
properties.Should().Equal(expected);
}
public static IQueryable <T> Include <T>(this IQueryable <T> query, Expression <Func <T, object> > selector) where T : class, new()
{
string path = new PropertyPathVisitor().GetPropertyPath(selector);
return(query.Include(path));
}
public static ObjectQuery <T> Include <T>(this ObjectQuery <T> query, Expression <Func <T, object> > selector)
{
string path = new PropertyPathVisitor().GetPropertyPath(selector);
return(query.Include(path));
}
public static ObjectQuery <TEntity> FetchMany <TEntity, TReleated>(this ObjectQuery <TEntity> query, Expression <Func <TEntity, IEnumerable <TReleated> > > selector) where TEntity : class
{
string path = new PropertyPathVisitor().GetPropertyPath(selector);
return(query.Include(path));
}
