egui_web: Add simple fetch API and demostrate it in example_web

build_demo_web.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+set -eu
+
+# Pre-requisites:
+rustup target add wasm32-unknown-unknown
+if ! wasm-bindgen --version; then
+	cargo clean
+	cargo install -f wasm-bindgen-cli
+	cargo update
+fi
+
+# BUILD=debug
+BUILD=release
+
+export RUSTFLAGS=--cfg=web_sys_unstable_apis # required for the clipboard API
+
+# Clear output from old stuff:
+rm -rf docs/demo_web.wasm
+
+echo "Build rust:"
+# cargo build -p demo_web --target wasm32-unknown-unknown
+cargo build --release -p demo_web --target wasm32-unknown-unknown
+
+echo "Generate JS bindings for wasm:"
+FOLDER_NAME=${PWD##*/}
+TARGET_NAME="demo_web.wasm"
+wasm-bindgen "target/wasm32-unknown-unknown/$BUILD/$TARGET_NAME" \
+  --out-dir docs --no-modules --no-typescript
+
+open http://localhost:8888/index.html