In this document
Introduction
OData is defined as "An open protocol to allow the creation and consumption of queryable and interoperable RESTful APIs in a simple and standard way" (odata.org). You can use OData with ASP.NET Boilerplate. The Abp.AspNetCore.OData NuGet package simplifies its usage.
Setup
Install NuGet Package
We must first install the Abp.AspNetCore.OData NuGet package to our Web.Core project:
Install-Package Abp.AspNetCore.OData
Set Module Dependency
We need to set a dependency on AbpAspNetCoreODataModule for our module. Example:
[DependsOn(typeof(AbpAspNetCoreODataModule))]
public class MyProjectWebCoreModule : AbpModule
{
...
}
See the module system to understand module dependencies.
Configure Your Entities
OData requires us to declare entities which can be used as OData resources. We must do this in the Startup class:
For asp net core 2.x
public class Startup
{
public IServiceProvider ConfigureServices(IServiceCollection services)
{
...
services.AddOData();
// Workaround: https://github.com/OData/WebApi/issues/1177
services.AddMvcCore(options =>
{
foreach (var outputFormatter in options.OutputFormatters.OfType<ODataOutputFormatter>().Where(_ => _.SupportedMediaTypes.Count == 0))
{
outputFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/prs.odatatestxx-odata"));
}
foreach (var inputFormatter in options.InputFormatters.OfType<ODataInputFormatter>().Where(_ => _.SupportedMediaTypes.Count == 0))
{
inputFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/prs.odatatestxx-odata"));
}
});
return services.AddAbp<MyProjectWebHostModule>(...);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
app.UseAbp();
...
app.UseOData(builder =>
{
builder.EntitySet<Person>("Persons").EntityType.Expand().Filter().OrderBy().Page();
});
// Return IQueryable from controllers
app.UseUnitOfWork(options =>
{
options.Filter = httpContext =>
{
return httpContext.Request.Path.Value.StartsWith("/odata");
};
});
app.UseMvc(routes =>
{
routes.MapODataServiceRoute(app);
...
});
}
}
For asp net core 3.x
public class Startup
{
public IServiceProvider ConfigureServices(IServiceCollection services)
{
...
services.AddOData();
// Workaround: https://github.com/OData/WebApi/issues/1177
services.AddMvcCore(options =>
{
foreach (var outputFormatter in options.OutputFormatters.OfType<ODataOutputFormatter>().Where(_ => _.SupportedMediaTypes.Count == 0))
{
outputFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/prs.odatatestxx-odata"));
}
foreach (var inputFormatter in options.InputFormatters.OfType<ODataInputFormatter>().Where(_ => _.SupportedMediaTypes.Count == 0))
{
inputFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/prs.odatatestxx-odata"));
}
});
return services.AddAbp<MyProjectWebHostModule>(...);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
app.UseAbp();
...
// Return IQueryable from controllers
app.UseUnitOfWork(options =>
{
options.Filter = httpContext => httpContext.Request.Path.Value.StartsWith("/odata");
});
app.UseODataBatching();
app.UseEndpoints(endpoints =>
{
...
var builder = new ODataConventionModelBuilder();
builder.EntitySet<Person>("Persons").EntityType.Expand().Filter().OrderBy().Page();
endpoints.MapODataRoute("odataPrefix", "odata", builder.GetEdmModel());
...
});
...
}
}
Here, we got the ODataModelBuilder reference and set the Person entity. You can use EntitySet to add other entities in a similar way. See the OData documentation for more information on the builder.
Create Controllers
The Abp.AspNetCore.OData NuGet package includes the AbpODataEntityController base class (which extends standard ODataController) to create your controllers easier. An example to create an OData endpoint for the Person entity:
public class PersonsController : AbpODataEntityController<Person>, ITransientDependency
{
public PersonsController(IRepository<Person> repository)
: base(repository)
{
}
}
It's that easy! All the methods of AbpODataEntityController are virtual. This means that you can override the Get, Post, Put, Patch, Delete and other actions and add your own logic.
Configuration
Abp.AspNetCore.OData calls the IRouteBuilder.MapODataServiceRoute method with the conventional configuration. If you need to, you can set Configuration.Modules.AbpAspNetCoreOData().MapAction to map OData routes yourself.
Examples
Here are some requests made to the controller defined above. Assume that the application works on http://localhost:21021. We will show some basic examples. Since OData is a standard protocol, you can easily find more advanced examples on the web.
Getting List of Entities
Getting all people.
Request
GET http://localhost:21021/odata/Persons
Response
{
"@odata.context":"http://localhost:21021/odata/$metadata#Persons","value":[
{
"Name":"Douglas Adams","IsDeleted":false,"DeleterUserId":null,"DeletionTime":null,"LastModificationTime":null,"LastModifierUserId":null,"CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":1
},{
"Name":"John Nash","IsDeleted":false,"DeleterUserId":null,"DeletionTime":null,"LastModificationTime":null,"LastModifierUserId":null,"CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":2
}
]
}
Getting a Single Entity
Getting the person with Id = 2.
Request
GET http://localhost:21021/odata/Persons(2)
Response
{
"@odata.context":"http://localhost:21021/odata/$metadata#Persons/$entity","Name":"John Nash","IsDeleted":false,"DeleterUserId":null,"DeletionTime":null,"LastModificationTime":null,"LastModifierUserId":null,"CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":2
}
Getting a Single Entity With Navigation Properties
Getting the person with Id = 1 including his/her phone numbers.
Request
GET http://localhost:21021/odata/Persons(1)?$expand=Phones
Response
{
"@odata.context":"http://localhost:21021/odata/$metadata#Persons/$entity","Name":"Douglas Adams","IsDeleted":false,"DeleterUserId":null,"DeletionTime":null,"LastModificationTime":null,"LastModifierUserId":null,"CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":1,"Phones":[
{
"PersonId":1,"Type":"Mobile","Number":"4242424242","CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":1
},{
"PersonId":1,"Type":"Mobile","Number":"2424242424","CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":2
}
]
}
Querying
Here's a more advanced query that includes filtering, sorting and getting the top 2 results.
Request
GET http://localhost:21021/odata/Persons?$filter=Name eq 'Douglas Adams'&$orderby=CreationTime&$top=2
Response
{
"@odata.context":"http://localhost:21021/odata/$metadata#Persons","value":[
{
"Name":"Douglas Adams","IsDeleted":false,"DeleterUserId":null,"DeletionTime":null,"LastModificationTime":null,"LastModifierUserId":null,"CreationTime":"2015-11-07T20:12:39.363+03:00","CreatorUserId":null,"Id":1
}
]
}
OData supports paging, sorting, filtering, projections and much more. See its own documentation for more information.
Creating a New Entity
In this example, we're creating a new person.
Request
POST http://localhost:21021/odata/Persons
{
Name: "Galileo Galilei"
}
Here, the "Content-Type" header is "application/json".
Response
{
"@odata.context": "http://localhost:21021/odata/$metadata#Persons/$entity",
"Name": "Galileo Galilei",
"IsDeleted": false,
"DeleterUserId": null,
"DeletionTime": null,
"LastModificationTime": null,
"LastModifierUserId": null,
"CreationTime": "2016-01-12T20:36:04.1628263+02:00",
"CreatorUserId": null,
"Id": 4
}
If we get the list again, we can see the new person. We can also update or delete an existing entity since OData supports it.
Getting MetaData
We can get the metadata of entities, as shown in this example.
Request
GET http://localhost:21021/odata/$metadata
Response
<?xml version="1.0" encoding="utf-8"?>
<edmx:Edmx Version="4.0" xmlns:edmx="http://docs.oasis-open.org/odata/ns/edmx">
<edmx:DataServices>
<Schema Namespace="AbpODataDemo.People" xmlns="http://docs.oasis-open.org/odata/ns/edm">
<EntityType Name="Person">
<Key>
<PropertyRef Name="Id" />
</Key>
<Property Name="Name" Type="Edm.String" Nullable="false" />
<Property Name="IsDeleted" Type="Edm.Boolean" Nullable="false" />
<Property Name="DeleterUserId" Type="Edm.Int64" />
<Property Name="DeletionTime" Type="Edm.DateTimeOffset" />
<Property Name="LastModificationTime" Type="Edm.DateTimeOffset" />
<Property Name="LastModifierUserId" Type="Edm.Int64" />
<Property Name="CreationTime" Type="Edm.DateTimeOffset" Nullable="false" />
<Property Name="CreatorUserId" Type="Edm.Int64" />
<Property Name="Id" Type="Edm.Int32" Nullable="false" />
<NavigationProperty Name="Phones" Type="Collection(AbpODataDemo.People.Phone)" />
</EntityType>
<EntityType Name="Phone">
<Key>
<PropertyRef Name="Id" />
</Key>
<Property Name="PersonId" Type="Edm.Int32" />
<Property Name="Type" Type="AbpODataDemo.People.PhoneType" Nullable="false" />
<Property Name="Number" Type="Edm.String" Nullable="false" />
<Property Name="CreationTime" Type="Edm.DateTimeOffset" Nullable="false" />
<Property Name="CreatorUserId" Type="Edm.Int64" />
<Property Name="Id" Type="Edm.Int32" Nullable="false" />
<NavigationProperty Name="Person" Type="AbpODataDemo.People.Person">
<ReferentialConstraint Property="PersonId" ReferencedProperty="Id" />
</NavigationProperty>
</EntityType>
<EnumType Name="PhoneType">
<Member Name="Unknown" Value="0" />
<Member Name="Mobile" Value="1" />
<Member Name="Home" Value="2" />
<Member Name="Office" Value="3" />
</EnumType>
</Schema>
<Schema Namespace="Default" xmlns="http://docs.oasis-open.org/odata/ns/edm">
<EntityContainer Name="Container">
<EntitySet Name="Persons" EntityType="AbpODataDemo.People.Person" />
</EntityContainer>
</Schema>
</edmx:DataServices>
</edmx:Edmx>
Metadata is used to investigate the service.
Sample Project
You can get the source code of the sample project here: https://github.com/aspnetboilerplate/sample-odata