Add common variables to context in render_response

src/routes.rs

     let posts: Vec<Post> = fs::get_all_posts().await?;
     let mut context = Context::new();
     context.insert("posts", &posts);
-    let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
-    context.insert("logged_in", &logged_in);
-    render_response("index.html", &context)
+    render_response("index.html", &context, &req)
 }
 
 pub async fn single_post(req: Request<()>) -> Result {
     let mut context = Context::new();
-    let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
-    context.insert("logged_in", &logged_in);
     let post_id = req.param("id")?;
     let post = fs::get_one_post(post_id).await?;
     context.insert("post", &post);
-    render_response("single.html", &context)
+    render_response("single.html", &context, &req)
 }
 
 pub async fn edit_post(req: Request<()>) -> Result {
-    let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
     let mut context = Context::new();
-    context.insert("logged_in", &logged_in);
     let post_id = req.param("id")?;
     let mut post = fs::get_one_post(post_id).await?;
     post.body = post.body.replace("<br>", "\n");
     context.insert("post", &post);
-    render_response("edit.html", &context)
+    render_response("edit.html", &context, &req)
 }
 
 pub async fn create_post(mut req: Request<()>) -> Result {
 
 pub async fn login_page(mut req: Request<()>) -> Result {
     let mut context = Context::new();
-    let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
-    context.insert("logged_in", &logged_in);
     match req.session_mut().get::<String>("flash_error") {
         Some(error) => {
             req.session_mut().remove("flash_error");
         }
         None => {}
     }
-    render_response("login.html", &context)
+    render_response("login.html", &context, &req)
 }
 
 pub async fn login(mut req: Request<()>) -> Result {
     Ok(Redirect::new("/").into())
 }
 
-pub fn render_response(template: &str, context: &Context) -> Result<Response> {
-    let html = render_template(template, context)?;
+pub fn render_response(template: &str, context: &Context, req: &Request<()>) -> Result<Response> {
+    let mut context = context.clone();
+    let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
+    context.insert("logged_in", &logged_in);
+    let html = render_template(template, &context)?;
     let mut res = Response::new(StatusCode::Ok);
     res.set_body(html);
     res.set_content_type(mime::HTML);