# EFx
[](https://crates.io/crates/efx)
[](#)
[](https://docs.rs/efx)
[](https://github.com/ZhukMax/efx/blob/main/LICENSE)
**EFx** — Rust 🦀 XML Template Engine for [egui](https://github.com/emilk/egui)-based frameworks: [eframe](https://github.com/emilk/egui/tree/master/crates/eframe), [bevy_egui](https://github.com/vladbat00/bevy_egui), [egui-winit](https://crates.io/crates/egui-winit), [egui-miniquad](https://github.com/not-fl3/egui-miniquad).
`efx!` is a proc-macro for writing tiny XML-like UI snippets in `eframe/egui`. It converts short tags into `egui` calls.
**Simplicity and Convenience — XML, 🚀 Speed and 🔐 Security — Rust**
**Easy as HTML, Fast as C**
You can embed arbitrary Rust expressions inside braces (`{...}`).
---
### Install & import
Requires `egui` (the project currently uses `egui 0.32`). Add to `Cargo.toml`:
```toml
[dependencies]
efx = "0.6"
egui = "0.32" # or egui-based framework
```
Inside this repo just import the macro:
```rust
use efx::efx; // the macro
```
---
### Documentation
You can see on web page https://docs.rs/efx/latest/efx/ or in files:
- [Introduction](efx/docs/intro.md) ([🇫🇷 fr](efx/docs/fr/intro.md))
- [Tags](efx/docs/tags.md) ([🇫🇷 fr](efx/docs/fr/tags.md))
- [Guide](efx/docs/guide.md) ([🇫🇷 fr](efx/docs/fr/guide.md))
---
### Expression interpolation `{...}`
Inside tag content you can insert any Rust expression that implements `Display`:
```rust
let a = 2;
let b = 3;
efx!(ui, r#"<Label>Sum: {a + b}</Label>"#);
```
#### Escaping braces
To print `{` or `}`, use double braces (same as `format!`):
```rust
efx!(ui, r#"<Label>Literals: {{ and }}</Label>"#);
```
---
### Errors & diagnostics
At compile time the macro parses your snippet; at runtime it shows readable diagnostics via `ui.Label(...)` when input is invalid:
* **Unknown tag**
Output: `Unknown tag: <TagName>`
* **Mismatched open/close tags**
Output: `Mismatched tags: <open> and </close>`
* **Interpolation count mismatch**
Happens if the parser found e.g. two `{expr}` parts but after processing the text there’s a different number of `{}` placeholders. Make the counts match.
---
### Current limitations
* **Case-sensitive tag names.**
* Interpolated expressions must implement `Display`.
---
### Roadmap & RFCs
**TL;DR.** EFx is a minimalist XML DSL on top of `egui` that compiles to plain `ui.*` calls.
The next three releases focus on expressiveness and first-class examples across popular `egui` runtimes:
* **0.7 — Themes & layouts:** lightweight style sheets, extended containers (`Tabs/Table` behind `extras`), perf & polish.
This plan is incremental and **non-breaking**; new features are opt-in. Priorities may change based on community feedback.
👉 **Full RFC:** [EFX-0001 — Roadmap 0.5–0.7](efx/docs/rfcs/EFX-0001-roadmap-0.5-0.7.md)
👉 **RFC index:** [RFC/README.md](efx/docs/rfcs/README.md)
---
### Supported `egui` runtimes
EFx renders into any runtime that provides `&mut egui::Ui`. We officially build examples for the following targets:
**Tier-1**
* `eframe` (native + wasm)
* `bevy_egui` (native)
* raw `winit+wgpu` (via `egui-winit` + `egui-wgpu`). [Wgpu](https://github.com/gfx-rs/wgpu) - a cross-platform, safe, pure-rust graphics API. It runs natively on Vulkan, Metal, D3D12, and OpenGL; and on top of WebGL2 and WebGPU on wasm. Follows WebGPU specification. With async/await API.
**Tier-2 (compatible today; examples later / community support)**
* `egui-miniquad` (for `macroquad/miniquad` overlays) - Relatively minimalistic API well suited for small to medium graphics projects. Supports multiple backends, including browser target.
* `egui_sdl2_*` backends
* `egui_glow` / `tao` (lower-level backends)
### Quickstart (pick one)
**A) eframe**
```toml
# Cargo.toml
[dependencies]
efx = "0.6"
eframe = "0.32"
```
```rust
use eframe::egui;
use efx::efx;
});
```
**B) Bevy + bevy\_egui**
```toml
# Cargo.toml
[dependencies]
efx = "0.6"
bevy = "0.16"
bevy_egui = "0.36" # re-exports `egui`
```
```rust
use bevy_egui::{EguiPlugin, EguiContexts};
use efx::efx;
bevy_egui::egui::Window::new("EFx").show(egui_ctx.ctx_mut(), |ui| {
efx!(ui, r#"<Row><Label>It works</Label></Row>"#);
});
```
> Tip: import `egui` via `use bevy_egui::egui as egui;` to avoid version mismatches.
**C) Raw winit + wgpu**
```toml
# Cargo.toml
[dependencies]
efx = "0.6"
egui = "0.32"
egui-winit = "0.32"
egui-wgpu = "0.32"
winit = "0.30"
wgpu = "26.0"
```
Use the example in `examples/winit_wgpu_min.rs` as a starting point.
---
### Contributing
[]()
**Thanks for considering a contribution!** Please follow this lightweight workflow:
#### 1) Pick or propose an issue
* **Claim an issue:** comment “I’d like to take this” (optionally add a brief plan/ETA).
The maintainer will assign it to you.
* **Propose a new issue:** open a ticket with a minimal reproducible example (for bugs) or a short rationale (for features).
Start with the roadmap RFC: [EFX-0001](efx/docs/rfcs/EFX-0001-roadmap-0.5-0.7.md).
> Tip: issues labeled `good first issue` are designed for first-time contributors.
#### 2) Fork & branch
* Fork the repository and create a **feature branch from `main`**:
```bash
git checkout main
git pull
git checkout -b feat/short-topic
```
* Keep your branch focused on **one issue**.
#### 3) Implement with tests & docs
* Make the change and add tests/docs where it makes sense.
* Local checks (examples build-only; no GUI run is required):
```bash
cargo fmt --all
cargo clippy --all-targets -- -D warnings
cargo build --workspace --locked
cargo build -p efx --example eframe_demo --locked
rustup target add wasm32-unknown-unknown
cargo build -p efx --example eframe_demo --target wasm32-unknown-unknown --locked
```
#### 4) Open a Pull Request
* Target the **next release branch** (e.g., `v0.6`, `v0.7`).
If the issue has a **milestone**, use the branch named after that milestone.
* Link the issue (e.g., “Closes #123”) and fill the checklist below.
**PR checklist**
* [ ] References the related issue / RFC section when behavior changes.
* [ ] CI is green (workspace build, examples, wasm32 build-only).
* [ ] Tests/docs updated where applicable.
* [ ] No unrelated changes.
#### 5) Reviews & merge
* Address review comments; small, focused PRs get merged faster.
* If you go silent for **7 days**, the issue may be unassigned to keep momentum (you can re-claim it anytime).
**Questions?** Reach out at [mail@zhukmax.com](mailto:mail@zhukmax.com).
---
### Changelog
See in file [Changelog.md](efx/Changelog.md)
### Licence
The MIT License. Please see [License File](efx/LICENSE) for more information.