Since Web API OData V5.5-beta, it supports the following types as function parameter:

  1. Primitive
  2. Enum
  3. Complex
  4. Entity
  5. Entity Reference
  6. Collection of above

Let’s see how to build and use the above types in function.

CLR Model

First of all, we create the following CLR classes as our model:

public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public class SubCustomer : Customer
{
    public double Price { get; set; }
}

public class Address
{
    public string City { get; set; }
}

public class SubAddress : Address
{
    public string Street { get; set; }
}

public enum Color
{
    Red,
    Blue,
    Green
}

Build Edm Model

Now, we can build the Edm Model as:

private static IEdmModel GetEdmModel()
{
    var builder = new ODataConventionModelBuilder();
    builder.EntitySet<Customer>("Customers");
    builder.ComplexType<Address>();
    builder.EnumType<Color>();

    BuildFunction(builder);
    return builder.GetEdmModel();
}

where, BuildFunction() is a helper function in which functions can be built.

Primitive and Collection of Primitive parameter

Configuration

In BuildFunction(), we can configure a function with Primitive and collection of Primitive parameters:

var function = builder.EntityType<Customer>().Collection.Function("PrimtiveFunction").Returns<string>();
function.Parameter<int>("p1");
function.Parameter<int?>("p2");
function.CollectionParameter<int>("p3");

Routing

In the CustomersController, add the following method:

[HttpGet]
public string PrimtiveFunction(int p1, int? p2, [FromODataUri]IEnumerable<int> p3)
{
   ...
}

Request Samples

We can invoke the function as:

~/odata/Customers/Default.PrimitiveFunction(p1=1,p2=9,p3=[1,3,5,7,9])
~/odata/Customers/Default.PrimitiveFunction(p1=2,p2=null,p3=[1,3,5,7,9])
~/odata/Customers/Default.PrimitiveFunction(p1=3,p2=null,p3=@p)?@p=[2,4,6,8]

Enum and Collection of Enum parameter

Configuration

In BuildFunction(), we can configure a function with Enum and collection of Enum parameters:

var function = builder.EntityType<Customer>().Collection.Function("EnumFunction").Returns<string>();
function.Parameter<Color>("e1");
function.Parameter<Color?>("e2"); // nullable
function.CollectionParameter<Color?>("e3"); // Collection of nullable

Routing

In the CustomersController, add the following method :

[HttpGet]
public string EnumFunction(Color e1, Color? e2, [FromODataUri]IEnumerable<Color?> e3)
{
  ...
}

Request Samples

We can invoke the Enum function as:

~/odata/Customers/Default.EnumFunction(e1=NS.Color'Red',e2=NS.Color'Green',e3=['Red', null, 'Blue'])
~/odata/Customers/Default.EnumFunction(e1=NS.Color'Blue',e2=null,e3=['Red', null, 'Blue'])
~/odata/Customers/Default.EnumFunction(e1=NS.Color'Blue',e2=null,e3=@p)?@p=['Red', null, 'Blue']

Complex and Collection of Complex parameter

Configuration

In BuildFunction(), we can configure a function with Complex and collection of Complex parameters:

var function = builder.EntityType<Customer>().Collection.Function("ComplexFunction").Returns<string>();
function.Parameter<Address>("c1");
function.CollectionParameter<Address>("c2");

Routing

In the CustomersController, add the following method :

[HttpGet]
public string ComplexFunction([FromODataUri]Address c1, [FromODataUri]IEnumerable<Address> c2)
{
  ...
}

Request Samples

We can invoke the complex function as:

~/odata/Customers/Default.ComplexFunction(c1=@x,c2=@y)?@x={\"@odata.type\":\"%23NS.Address\",\"City\":\"Redmond\"}&@y=[{\"@odata.type\":\"%23NS.Address\",\"City\":\"Redmond\"},{\"@odata.type\":\"%23NS.SubAddress\",\"City\":\"Shanghai\", \"Street\":\"Zi Xing Rd\"}]
~/odata/Customers/Default.ComplexFunction(c1={\"@odata.type\":\"%23NS.Address\",\"City\":\"Redmond\"},c2=[{\"@odata.type\":\"%23NS.Address\",\"City\":\"Redmond\"},{\"@odata.type\":\"%23NS.SubAddress\",\"City\":\"Shanghai\", \"Street\":\"Zi Xing Rd\"}])
~/odata/Customers/Default.ComplexFunction(c1=null,c2=@p)?@p=[null,{\"@odata.type\":\"%23NS.SubAddress\",\"City\":\"Shanghai\", \"Street\":\"Zi Xing Rd\"}]

Entity and Collection of Entity parameter

Configuration

In BuildFunction(), we can configure a function with Entity and collection of Entity parameters:

var function = builder.EntityType<Customer>().Collection.Function("EntityFunction").Returns<string>();
function.EntityParameter<Customer>("a1");
function.CollectionEntityParameter<Customer>("a2");

It’s better to call EntityParameter<T> and CollectionEntityParameter<T> to define entity and collection of entity parameter.

Routing

In the CustomersController, add the following method :

[HttpGet]
public string EntityFunction([FromODataUri]Customer a1, [FromODataUri]IEnumerable<Customer> a2)
{
  ...
}

Request Samples

We can invoke the entity function as:

~/odata/Customers/Default.EntityFunction(a1=@x,a2=@y)?@x={\"@odata.type\":\"%23NS.Customer\",\"Id\":1,\"Name\":\"John\"}&@y={\"value\":[{\"@odata.type\":\"%23NS.Customer\",\"Id\":2, \"Name\":\"Mike\"},{\"@odata.type\":\"%23NS.SubCustomer\",\"Id\":3,\"Name\":\"Tony\", \"Price\":9.9}]}
~/odata/Customers/Default.EntityFunction(a1=@x,a2=@y)?@x=null&@y={\"value\":[]}

However, only parameter alias is supported for entity.

Entity Reference and collection of Entity Reference parameter

In fact, we can’t build a function with entity reference as parameter. However, we can call the function with entity parameter using entity reference value. So, without any change for the EntityFunction, we can call as:

~/odata/Customers/Default.EntityFunction(a1=@x,a2=@y)?@x={\"@odata.id\":\"http://localhost/odata/Customers(2)\"}&@y={\"value\":[{\"@odata.id\":\"http://localhost/odata/Customers(2)\"},{\"@odata.id\":\"http://localhost/odata/Customers(3)\"}]}

FromODataUri

‘[FromODataUri]’ is mandatory for complex, entity and all collection. However, it is optional for Primitive & Enum. But for string primitive type, the value will contain single quotes without ‘[FromODataUri]’.

Thanks.

For un-typed scenario, please refer to untyped page.