Use build script to generate elements with inline JS

kmicklas · Jun 21, 2024 · 8cf4479 · 8cf4479
1 parent 4409078
commit 8cf4479
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Showing 6 changed files with 190 additions and 37 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -19,5 +19,6 @@ log = "0.4.21"
 paste = "1.0.15"
 ravel = { version = "0.2.0", path = "./ravel" }
 ravel-web = { version = "0.3.0", path = "./ravel-web" }
+wasm-bindgen = "0.2.92"
 wasm-bindgen-futures = "0.4.42"
 web-sys = "0.3.69"
diff --git a/ravel-web/Cargo.toml b/ravel-web/Cargo.toml
@@ -12,5 +12,10 @@ futures-micro.workspace = true
 gloo-events.workspace = true
 gloo-utils.workspace = true
 ravel.workspace = true
+wasm-bindgen.workspace = true
 wasm-bindgen-futures.workspace = true
 web-sys = { workspace = true, features = ["Node", "Element", "Text", "Comment"] }
+
+[build-dependencies]
+serde = { version = "1.0.203", features = ["derive"] }
+toml = "0.8.14"
diff --git a/ravel-web/build.rs b/ravel-web/build.rs
@@ -0,0 +1,65 @@
+use std::fmt::Write as _;
+
+use serde::Deserialize;
+
+#[derive(Deserialize)]
+struct Config {
+    element: std::collections::HashMap<String, Element>,
+}
+
+#[derive(Deserialize)]
+struct Element {
+    // TODO: JS element type
+}
+
+fn main() {
+    let config = std::fs::read_to_string("generate.toml").unwrap();
+    let config: Config = toml::from_str(&config).unwrap();
+
+    let out_dir = std::env::var_os("OUT_DIR").unwrap();
+    let out_dir = std::path::PathBuf::from(out_dir);
+
+    let mut src = String::new();
+
+    src.push_str("#[wasm_bindgen::prelude::wasm_bindgen(inline_js = r#\"\n");
+
+    for name in config.element.keys() {
+        writeln!(&mut src, "export function create_{name}() {{return document.createElement(\"{name}\")}}").unwrap();
+    }
+
+    src.push_str("\"#)]\n");
+    src.push_str("extern \"C\" {\n");
+
+    for (name, Element {}) in &config.element {
+        writeln!(&mut src, "fn create_{name}() -> web_sys::Element;").unwrap();
+    }
+
+    src.push_str("}\n");
+
+    for name in config.element.keys() {
+        let t = title_case(name);
+        writeln!(&mut src, "make_el!({name}, {t}, create_{name}());").unwrap();
+
+        // Ideally this would be part of `make_el`, but rust-analyzer can't
+        // seem to handle doc attributes generated by a macro generated by a
+        // build script.
+        writeln!(&mut src, "/// `{name}` element.").unwrap();
+        writeln!(
+            &mut src,
+            "pub fn {name}<Body>(body: Body) -> {t}<Body> {{ {t}(body) }}"
+        )
+        .unwrap();
+    }
+
+    std::fs::write(out_dir.join("el_gen.rs"), src).unwrap();
+
+    println!("cargo::rerun-if-changed=generate.toml");
+}
+
+fn title_case(s: &str) -> String {
+    let mut cs = s.chars();
+    match cs.next() {
+        None => String::new(),
+        Some(c) => c.to_uppercase().collect::<String>() + cs.as_str(),
+    }
+}
diff --git a/ravel-web/generate.toml b/ravel-web/generate.toml
@@ -0,0 +1,27 @@
+[element]
+a = {}
+b = {}
+button = {}
+div = {}
+footer = {}
+form = {}
+h1 = {}
+h2 = {}
+h3 = {}
+h4 = {}
+h5 = {}
+h6 = {}
+header = {}
+input = {}
+label = {}
+li = {}
+p = {}
+section = {}
+span = {}
+strong = {}
+table = {}
+tbody = {}
+td = {}
+thead = {}
+tr = {}
+ul = {}
diff --git a/ravel-web/src/el.rs b/ravel-web/src/el.rs
@@ -25,7 +25,7 @@ impl<Kind: ElKind, Body: Builder<Web>> Builder<Web> for El<Kind, Body> {
     type State = ElState<Body::State>;
 
     fn build(self, cx: BuildCx) -> Self::State {
-        build_el(cx, Kind::NAME, self.body)
+        build_el(cx, create_element(Kind::NAME), self.body)
     }
 
     fn rebuild(self, cx: RebuildCx, state: &mut Self::State) {
@@ -64,13 +64,15 @@ pub fn el<Kind: ElKind, Body>(_: Kind, body: Body) -> El<Kind, Body> {
     }
 }
 
+fn create_element(kind: &'static str) -> web_sys::Element {
+    gloo_utils::document().create_element(kind).unwrap_throw()
+}
+
 fn build_el<Body: Builder<Web>>(
     cx: BuildCx,
-    kind: &'static str,
+    el: web_sys::Element,
     body: Body,
 ) -> ElState<Body::State> {
-    let el = gloo_utils::document().create_element(kind).unwrap_throw();
-
     let state = body.build(BuildCx {
         position: Position {
             parent: &el,
@@ -88,7 +90,7 @@ fn build_el<Body: Builder<Web>>(
 }
 
 macro_rules! make_el {
-    ($name:ident, $t:ident) => {
+    ($name:ident, $t:ident, $create:expr) => {
         #[doc = concat!("`", stringify!($name), "` element.")]
         #[repr(transparent)]
         #[derive(Copy, Clone)]
@@ -98,7 +100,7 @@ macro_rules! make_el {
             type State = ElState<Body::State>;
 
             fn build(self, cx: BuildCx) -> Self::State {
-                build_el(cx, stringify!($name), self.0)
+                build_el(cx, $create, self.0)
             }
 
             fn rebuild(self, cx: RebuildCx, state: &mut Self::State) {
@@ -111,37 +113,7 @@ macro_rules! make_el {
                 )
             }
         }
-
-        #[doc = concat!("`", stringify!($name), "` element.")]
-        pub fn $name<Body>(body: Body) -> $t<Body> {
-            $t(body)
-        }
     };
 }
 
-make_el!(a, A);
-make_el!(b, B);
-make_el!(button, Button);
-make_el!(div, Div);
-make_el!(footer, Footer);
-make_el!(form, Form);
-make_el!(h1, H1);
-make_el!(h2, H2);
-make_el!(h3, H3);
-make_el!(h4, H4);
-make_el!(h5, H5);
-make_el!(h6, H6);
-make_el!(header, Header);
-make_el!(input, Input);
-make_el!(label, Label);
-make_el!(li, Li);
-make_el!(p, P);
-make_el!(section, Section);
-make_el!(span, Span);
-make_el!(strong, Strong);
-make_el!(table, Table);
-make_el!(tbody, TBody);
-make_el!(thead, THead);
-make_el!(td, Td);
-make_el!(tr, Tr);
-make_el!(ul, Ul);
+include!(concat!(env!("OUT_DIR"), "/el_gen.rs"));