Async + WASM Plugins #73

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 resolver = "2"
-members = ["server", "cli", "lib"]
+members = ["server", "cli", "lib", "plugin-examples/random-folder-extender"]
 # Tauri build is deprecated, see
 # https://github.com/atomicdata-dev/atomic-server/issues/718
 exclude = ["desktop"]

atomic-plugin/CONTRIBUTING.md

@@ -0,0 +1,22 @@
+# Contributing to Atomic Plugin
+
+When updating the bindings, keep the following in mind:
+There is a weird issue where the bindings do not work when using the standard `wit_bidgen::generate!` macro.
+To get the right bindings change bindings.rs to the following:
+
+```rust
+wit_bindgen::generate!({
+    path: "wit/class-extender.wit",
+    world: "class-extender",
+    pub_export_macro: true,
+});
+```
+
+Then run `cargo component check` on the atomic-plugin crate, for some reason this expands the macro in a way that it actually works.
+The only thing left is to mark the following macro as exported:
+
+```rust
+#[doc(hidden)]
+#[macro_export] // <-- add this line
+macro_rules! __export_world_class_extender_cabi {
+```

atomic-plugin/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "atomic-plugin"
+version = "0.1.1"
+edition = "2021"
+description = "Helper library for building Atomic Data class extender plugins in Wasm"
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+wit-bindgen = { version = "0.48.1", features = ["realloc", "macros"] }
+wit-bindgen-rt = "0.44.0"

atomic-plugin/README.md

@@ -0,0 +1,44 @@
+# atomic-plugin
+
+A helper library that removes a lot of the boilerplate when building AtomicServer Wasm plugins.
+
+## Class Extenders
+
+Atomic Data Classextenders are plugins that can modify the behavior of an Atomic Data class.
+For example you might want to add some custom verification logic to a class
+
+## How to use
+
+Simply implement the `ClassExtender` trait on a struct and export it using the `export_plugin!` macro.
+
+```rust
+use atomic_plugin::{ClassExtender, Commit, Resource};
+
+struct FolderExtender;
+
+impl ClassExtender for FolderExtender {
+  // REQUIRED: Returns the class that this class extender applies to.
+    fn class_url() -> String {
+        "https://atomicdata.dev/classes/Folder".to_string()
+    }
+
+    // Prevent commits where the name contains "Tailwind CSS".
+    fn before_commit(commit: &Commit, _snapshot: Option<&Resource>) -> Result<(), String> {
+        let Some(set) = &commit.set else {
+            return Ok(());
+        };
+
+        let Some(name) = set.get(NAME_PROP).and_then(|val| val.as_str()) else {
+            return Ok(());
+        };
+
+        if name.contains("Tailwind CSS") {
+            return Err("Tailwind CSS is not allowed".into());
+        }
+
+        Ok(())
+    }
+}
+
+atomic_plugin::export_plugin!(FolderExtender);
+```