A route template is the string parameter of an ASP.NET Core HTTP attribute. It describes URL segments that help select an endpoint action after the controller segment has matched. section 5.4.1
For a single-resource GET endpoint:
- Use [HttpGet("{id}")] to declare one route segment named id. section 5.4.1
- Let ASP.NET Core combine the controller route, such as catalog, with the template to distinguish actions. section 5.4.1
- Bind the route value to an action parameter such as int id. section 5.4.1
Requesting one book
The route [HttpGet("{id}")] on GetBook(int id) allows https://localhost:<port>/catalog/1 to select the single-book action rather than the list action. section 5.4.1
Listing 5.27 HTTP GET method to request a single Book object by id
[HttpGet("{id}")] #1
public Task<Book?> GetBook(int id) #2
{
return _dbContext.Books.FirstOrDefaultAsync( #3
b => b.Id == id);
}
Inspect the focused controller listing that implements a single-resource route with an id parameter. section 5.4.1
