restructure folders

templating/tera/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "template-tera"
+version = "1.0.0"
+edition = "2021"
+
+[dependencies]
+env_logger = "0.9.0"
+tera = "1.8.0"
+actix-web = "4.0.0-beta.21"

templating/tera/README.md

@@ -0,0 +1,18 @@
+# template_tera
+
+Minimal example of using the template [tera](https://github.com/Keats/tera) that displays a form.
+
+## Usage
+
+### server
+
+```bash
+cd template_engines/tera
+cargo run (or ``cargo watch -x run``)
+# Started http server: 127.0.0.1:8080
+```
+
+### web client
+
+- [http://localhost:8080](http://localhost:8080)
+- [http://localhost:8080/non-existing-page](http://localhost:8080/non-existing-page) - 404 page rendered using template

templating/tera/src/main.rs

@@ -0,0 +1,93 @@
+use actix_web::body::BoxBody;
+use actix_web::dev::ServiceResponse;
+use actix_web::http::header::ContentType;
+use actix_web::http::StatusCode;
+use actix_web::middleware::{ErrorHandlerResponse, ErrorHandlers};
+use actix_web::{error, middleware, web, App, Error, HttpResponse, HttpServer, Result};
+use std::collections::HashMap;
+use tera::Tera;
+
+// store tera template in application state
+async fn index(
+    tmpl: web::Data<tera::Tera>,
+    query: web::Query<HashMap<String, String>>,
+) -> Result<HttpResponse, Error> {
+    let s = if let Some(name) = query.get("name") {
+        // submitted form
+        let mut ctx = tera::Context::new();
+        ctx.insert("name", &name.to_owned());
+        ctx.insert("text", &"Welcome!".to_owned());
+        tmpl.render("user.html", &ctx)
+            .map_err(|_| error::ErrorInternalServerError("Template error"))?
+    } else {
+        tmpl.render("index.html", &tera::Context::new())
+            .map_err(|_| error::ErrorInternalServerError("Template error"))?
+    };
+    Ok(HttpResponse::Ok().content_type("text/html").body(s))
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    std::env::set_var("RUST_LOG", "actix_web=info");
+    env_logger::init();
+
+    println!("Listening on: 127.0.0.1:8080, open browser and visit have a try!");
+    HttpServer::new(|| {
+        let tera =
+            Tera::new(concat!(env!("CARGO_MANIFEST_DIR"), "/templates/**/*")).unwrap();
+
+        App::new()
+            .app_data(web::Data::new(tera))
+            .wrap(middleware::Logger::default()) // enable logger
+            .service(web::resource("/").route(web::get().to(index)))
+            .service(web::scope("").wrap(error_handlers()))
+    })
+    .bind(("127.0.0.1", 8080))?
+    .run()
+    .await
+}
+
+// Custom error handlers, to return HTML responses when an error occurs.
+fn error_handlers() -> ErrorHandlers<BoxBody> {
+    ErrorHandlers::new().handler(StatusCode::NOT_FOUND, not_found)
+}
+
+// Error handler for a 404 Page not found error.
+fn not_found<B>(res: ServiceResponse<B>) -> Result<ErrorHandlerResponse<BoxBody>> {
+    let response = get_error_response(&res, "Page not found");
+    Ok(ErrorHandlerResponse::Response(ServiceResponse::new(
+        res.into_parts().0,
+        response.map_into_left_body(),
+    )))
+}
+
+// Generic error handler.
+fn get_error_response<B>(res: &ServiceResponse<B>, error: &str) -> HttpResponse {
+    let request = res.request();
+
+    // Provide a fallback to a simple plain text response in case an error occurs during the
+    // rendering of the error page.
+    let fallback = |e: &str| {
+        HttpResponse::build(res.status())
+            .content_type(ContentType::plaintext())
+            .body(e.to_string())
+    };
+
+    let tera = request.app_data::<web::Data<Tera>>().map(|t| t.get_ref());
+    match tera {
+        Some(tera) => {
+            let mut context = tera::Context::new();
+            context.insert("error", error);
+            context.insert("status_code", res.status().as_str());
+            let body = tera.render("error.html", &context);
+
+            match body {
+                Ok(body) => HttpResponse::build(res.status())
+                    .content_type(ContentType::html())
+                    .body(body),
+                Err(_) => fallback(error),
+            }
+        }
+        None => fallback(error),
+    }
+}

templating/tera/templates/error.html

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8" />
+  <title>{{ error }}</title>
+</head>
+<body>
+  <h1>{{ status_code }} {{ error }}</h1>
+</body>
+</html>

templating/tera/templates/index.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8" />
+  <title>Actix Web</title>
+</head>
+<body>
+  <h1>Welcome!</h1>
+  <p>
+    <h3>What is your name?</h3>
+    <form>
+      <input type="text" name="name" /><br/>
+      <p><input type="submit"></p>
+    </form>
+  </p>
+</body>
+</html>

templating/tera/templates/user.html

@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8" />
+  <title>Actix Web</title>
+</head>
+<body>
+  <h1>Hi, {{ name }}!</h1>
+  <p>
+    {{ text }}
+  </p>
+</body>
+</html>