Optionally implement Iron's Modifier<Response> for templates

4 files changed, 25 insertions, 0 deletions

diff --git a/askama/Cargo.toml b/askama/Cargo.toml
index 32a8c03..f96b939 100644
--- a/askama/Cargo.toml
+++ b/askama/Cargo.toml
@@ -20,10 +20,12 @@ askama_derive = { path = "../askama_derive", version = "0.3.4" }
 error-chain = "0.10"
 serde = { version = "1.0", optional = true }
 serde_json = { version = "1.0", optional = true }
+iron = { version = "0.5", optional = true }
 
 [features]
 serde-json = ["serde", "serde_json"]
 default = []
+with-iron = ["iron", "askama_derive/iron"]
 
 [package.metadata.docs.rs]
 features = [ "serde-json" ]
diff --git a/askama/src/lib.rs b/askama/src/lib.rs
index 1870363..4d9b2fb 100644
--- a/askama/src/lib.rs
+++ b/askama/src/lib.rs
@@ -243,6 +243,13 @@ pub mod filters;
 pub use askama_derive::*;
 pub use errors::Result;
 
+#[cfg(feature = "with-iron")]
+pub mod iron {
+    extern crate iron;
+    pub use self::iron::modifier::Modifier;
+    pub use self::iron::response::Response;
+}
+
 // Duplicates askama_derive::path::template_dir()
 fn template_dir() -> PathBuf {
     let mut path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
diff --git a/askama_derive/Cargo.toml b/askama_derive/Cargo.toml
index 3bec13a..40f1ad5 100644
--- a/askama_derive/Cargo.toml
+++ b/askama_derive/Cargo.toml
@@ -11,6 +11,10 @@ workspace = ".."
 [lib]
 proc-macro = true
 
+[features]
+default = []
+iron = []
+
 [dependencies]
 nom = "3"
 syn = "0.11"
diff --git a/askama_derive/src/generator.rs b/askama_derive/src/generator.rs
index 6eb16e8..57d54b1 100644
--- a/askama_derive/src/generator.rs
+++ b/askama_derive/src/generator.rs
@@ -53,6 +53,9 @@ pub fn generate(ast: &syn::DeriveInput, path: &Path, mut nodes: Vec<Node>) -> St
         gen.impl_template(ast, &content);
     }
     gen.impl_display(ast);
+    if cfg!(feature = "iron") {
+        gen.impl_modifier_response(ast);
+    }
     gen.result()
 }
 
@@ -618,6 +621,15 @@ impl<'a> Generator<'a> {
         self.writeln("}");
     }
 
+    // Implement iron's Modifier<Response> if enabled
+    fn impl_modifier_response(&mut self, ast: &syn::DeriveInput) {
+        self.write_header(ast, "::askama::iron::Modifier<::askama::iron::Response>");
+        self.writeln("fn modify(self, res: &mut ::askama::iron::Response) {");
+        self.writeln("res.body = Some(Box::new(self.render().unwrap().into_bytes()));");
+        self.writeln("}");
+        self.writeln("}");
+    }
+
     fn result(self) -> String {
         self.buf
     }