Add some functions to read/write request header for server functions (#4823)

* Add some functions to read/write request header for server functions

* Use LazyLock<Mutex<_>> to allow rewriting and clearing request headers.

packages/fullstack/src/client.rs

@@ -9,7 +9,8 @@ use headers::{ContentType, Header};
 use http::{response::Parts, Extensions, HeaderMap, HeaderName, HeaderValue, Method, StatusCode};
 use send_wrapper::SendWrapper;
 use serde::{de::DeserializeOwned, Serialize};
-use std::{fmt::Display, pin::Pin, prelude::rust_2024::Future, sync::OnceLock};
+use std::sync::{LazyLock, Mutex, OnceLock};
+use std::{fmt::Display, pin::Pin, prelude::rust_2024::Future};
 use url::Url;
 
 pub static GLOBAL_REQUEST_CLIENT: OnceLock<reqwest::Client> = OnceLock::new();
@@ -49,10 +50,12 @@ impl ClientRequest {
         .parse()
         .unwrap();
 
+        let headers = get_request_headers();
+
         ClientRequest {
             method,
             url,
-            headers: HeaderMap::new(),
+            headers,
             extensions: Extensions::new(),
         }
     }
@@ -505,6 +508,23 @@ pub fn get_server_url() -> &'static str {
 
 static ROOT_URL: OnceLock<&'static str> = OnceLock::new();
 
+/// Delete the extra request headers for all servers functions.
+pub fn clear_request_headers() {
+    REQUEST_HEADERS.lock().unwrap().clear();
+}
+
+/// Set the extra request headers for all servers functions.
+pub fn set_request_headers(headers: HeaderMap) {
+    *REQUEST_HEADERS.lock().unwrap() = headers;
+}
+
+/// Returns the extra request headers for all servers functions.
+pub fn get_request_headers() -> HeaderMap {
+    REQUEST_HEADERS.lock().unwrap().clone()
+}
+
+static REQUEST_HEADERS: LazyLock<Mutex<HeaderMap>> = LazyLock::new(|| Mutex::new(HeaderMap::new()));
+
 pub trait ClientResponseDriver {
     fn status(&self) -> StatusCode;
     fn headers(&self) -> &HeaderMap;