From 7d209454b105bfac3219e94a7c0d88e3389a6a46 Mon Sep 17 00:00:00 2001
From: sakex <alexandre@senges.ch>
Date: Fri, 21 Jul 2023 14:48:49 +0200
Subject: [PATCH] expose-method

---
 src/SUMMARY.md                                |  1 +
 .../server/files/index.html                   |  2 +-
 src/webassembly/expose-method.md              | 23 ++++++++++++++++++
 src/webassembly/load-wasm-module.md           | 24 ++++++++++++++++++-
 4 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 src/webassembly/expose-method.md

diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index 75e3e96e..2c578e9a 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -301,6 +301,7 @@
 ----
 - [WebAssembly basics](webassembly.md)
   - [Load a WASM module](webassembly/load-wasm-module.md)
+  - [Expose a method](webassembly/expose-method.md)
 
 # Final Words
 
diff --git a/src/rust-wasm-template/server/files/index.html b/src/rust-wasm-template/server/files/index.html
index f9e9f161..1876111d 100644
--- a/src/rust-wasm-template/server/files/index.html
+++ b/src/rust-wasm-template/server/files/index.html
@@ -87,7 +87,7 @@
     This repository contains the minimum amount of code needed to experiment with WebAssembly. Including a web server to serve the HTML and WASM as well as the javascript boilerplate needed to load WASM.
 </p>
 <p>
-    Edit <a href="">server/files/index.mjs</a> to edit the Javascript.
+    Edit <a href="https://github.com/google/comprehensive-rust/tree/main/src/rust-wasm-template/server/files/index.mjs">server/files/index.mjs</a> to edit the Javascript.
 </p>
 <p>
 WASM output: <span id="wasmoutput" />
diff --git a/src/webassembly/expose-method.md b/src/webassembly/expose-method.md
new file mode 100644
index 00000000..5bd354dc
--- /dev/null
+++ b/src/webassembly/expose-method.md
@@ -0,0 +1,23 @@
+# Expose a method
+
+The first thing you will want to do with WebAssembly is expose your methods to Javascript.
+This is straightforward using the `#[wasm_bindgen]` procedural macro.
+
+```rust
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn set_panic_hook() {
+    // Generates better error messages if our code ever panics.
+    //
+    // For more details see
+    // https://github.com/rustwasm/console_error_panic_hook#readme
+    console_error_panic_hook::set_once();
+}
+
+// Exposes the `add` method from the previous slide
+#[wasm_bindgen]
+pub fn add(a: i32, b: i32) -> i32 {
+    a + b
+}
+```
diff --git a/src/webassembly/load-wasm-module.md b/src/webassembly/load-wasm-module.md
index 63bdb2fd..ac2e2502 100644
--- a/src/webassembly/load-wasm-module.md
+++ b/src/webassembly/load-wasm-module.md
@@ -1,7 +1,29 @@
 # Load a WASM module
 
+## Commands to run:
+
+You can compile the basic WASM library provided in [rust-wasm-template](https://github.com/google/comprehensive-rust/tree/main/src/rust-wasm-template) with this command:
+
+```shell
+cd src/rust-wasm-template/project
+
+wasm-pack build --target web && cp -r pkg ../server
+```
+
+You can start the web server provided in [rust-wasm-template](https://github.com/google/comprehensive-rust/tree/main/src/rust-wasm-template) with this command:
+
+
+```shell
+cd src/rust-wasm-template/server
+
+cargo run
+```
+
+Open the web page on port `8080`. HTML and JS files are provided at [rust-wasm-template/server](https://github.com/google/comprehensive-rust/tree/main/src/rust-wasm-template/server/files).
+
+## Javascript
+
 Once you have compiled your WebAssembly module, you want to call it from your Web application.
-This chapter will cover minimum amount of Javascript required to load a WASM module into a Web application.
 
 ```javascript
 // Import the module and the exported method `add`