[actix-web] Add support for actix-web >= 2.0.0

In order to support both actix-web < 2.0.0 and >= 2.0.0 at the same
time I added a feature actix-web-2, which enables the actix-web
dependency with the respective version und the name active-web-2-dep
and the futures dependency which is required(?) for implementing the
Responder trait for >= 2.0.0.

Thus the user of maud has the choice to use actix-web in the version
they prefer.

Author: czyba

maud/Cargo.toml

@@ -11,12 +11,17 @@ description = "Compile-time HTML templates."
 categories = ["template-engine"]
 edition = "2018"
 
+[features]
+actix-web-2 = ["actix-web-2-dep", "futures"]
+
 [dependencies]
 maud_htmlescape = { version = "0.17.0", path = "../maud_htmlescape" }
 maud_macros = { version = "0.21.0", path = "../maud_macros" }
 iron = { version = ">= 0.5.1, < 0.7.0", optional = true }
 rocket = { version = ">= 0.3, < 0.5", optional = true }
 actix-web = { version = "1.0.0", optional = true, default-features = false }
+actix-web-2-dep = { version = "2.0.0", optional = true, default-features = false, package = "actix-web" }
+futures = { version = "0.3.0", optional = true }
 
 [dev-dependencies]
 compiletest_rs = { version = "0.3.19", features = ["stable"] }

maud/src/lib.rs

@@ -206,3 +206,20 @@ mod actix_support {
         }
     }
 }
+
+#[cfg(feature = "actix-web-2")]
+mod actix2_support {
+    use crate::PreEscaped;
+    use actix_web_2_dep::{Responder, HttpResponse, HttpRequest, Error};
+    use futures::future::{ok, Ready};
+
+    impl Responder for PreEscaped<String> {
+        type Error = Error;
+        type Future = Ready<Result<HttpResponse, Self::Error>>;
+        fn respond_to(self, _req: &HttpRequest) -> Self::Future {
+            ok(HttpResponse::Ok()
+               .content_type("text/html; charset=utf-8")
+               .body(self.0))
+        }
+    }
+}