I want to take an environmental variable and prefix it to the route for all the controllers. So in Controllers I have the followings:
[ApiController]
[Route("[controller]")]
public class DashboardsController : ControllerBase
{.......}
Program.cs routing part ==>
app.UseRouting();
app.UseAuthorization();
app.MapControllers();
app.Run();
I have tried creating a class with constant strings and putting into the Route attribute but as you know we cannot change constants, so this didn't work.
The [Route] attribute implements a IRouteTemplateProvider interface, which defines a Template property that returns the route template.
If you implement a custom attribute, say [DynamicRoute], that takes an environment variable name as a parameter, you could set the Template property to a different value based on the environment variable passed in.
This works for me:
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public sealed class DynamicRouteAttribute : Attribute, IRouteTemplateProvider
{
public DynamicRouteAttribute(string environmentVariableName)
{
ArgumentNullException.ThrowIfNull(environmentVariableName);
Template = Environment.GetEnvironmentVariable(environmentVariableName);
}
public string? Template { get; }
public int? Order { get; set; }
public string? Name { get; set; }
}
Replace [Route("[controller]")] in your controller with [DynamicRoute("yourEnvVarName")] and it will start to honor whatever you configure in your environment variable.
After @julealgon's answer, this is the final solution.
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public sealed class DynamicRouteAttribute : RouteAttribute
{
public DynamicRouteAttribute(string template)
: base($"{Environment.GetEnvironmentVariable("test")}/{template}")
{
ArgumentNullException.ThrowIfNull(template);
}
}