RSCx - Rust Server Components
RSCx is a server-side HTML rendering engine library with a neat developer experience and great performance.
Features:
- all components are async functions
- JSX-like syntax called RSX parsed with rstml
- contexts, to easily pass values down the components tree (example)
- inspired by Maud and Leptos
⚠️ Warning: not production-ready yet. It lacks important features such as HTML escaping!
Usage
All the examples can be found in rscx/examples/.
use ;
async
// simple function returning a String
// it will call the Items() function
async
/// mark functions with #[component] to use them as components inside html! macro
] title: String,
children: String,
)
async
/// async functions can be easily used in the body of a component, as every component is an async
/// function
async
Benchmarks
RSCx is fast.
Disclaimer: RSCx is for servers, as the name suggests. Therefore the following comparisons with Leptos are unfair. This library contains only a fraction of Leptos' features.
Disclaimer 2: The benchmarks are pretty basics and should not influence your decision on whether to use or not this library. Focus on the DX. They are included as I kept running them to make sure I didn't fall too much behind alternatives.
The time in the middle of the three is the average.
Run the benchmarks locally
cd bench
# cargo install criterion
cargo criterion
Benchmark 1: single element, lots of HTML attributes
many_attrs/maud_many_attrs
time: [205.89 ns 208.35 ns 211.53 ns]
many_attrs/horrorshow_many_attrs
time: [37.221 µs 37.304 µs 37.401 µs]
many_attrs/html_node_many_attrs
time: [67.726 µs 67.830 µs 67.939 µs]
many_attrs/leptos_many_attrs
time: [923.31 ns 928.46 ns 935.04 ns]
many_attrs/rscx_many_attrs
time: [207.96 ns 212.82 ns 219.28 ns]
RSCx and Maud pretty much are the same as their macros output is effectively a static string with the result.
Benchmark 2: little element with props and child
small_fragment/maud_small_fragment
time: [107.60 ns 107.71 ns 107.81 ns]
small_fragment/horrorshow_small_fragment
time: [405.98 ns 406.08 ns 406.21 ns]
small_fragment/leptos_small_fragment
time: [1.7641 µs 1.7652 µs 1.7662 µs]
small_fragment/rscx_small_fragment
time: [101.79 ns 101.87 ns 101.97 ns]
RSCx offers a better DX than Maud, as the syntax is nicer and values such as i32 can be passed as props/attributes, while in Maud every attribute must be a static string.
Benchmark 3: dynamic attributes (read for variable)
many_dyn_attrs/horrorshow_many_dyn_attrs
time: [50.445 µs 50.702 µs 50.977 µs]
many_dyn_attrs/leptos_many_dyn_attrs
time: [100.13 µs 100.52 µs 101.00 µs]
many_dyn_attrs/rscx_many_dyn_attrs
time: [33.953 µs 33.990 µs 34.037 µs]
Benchmark 4: async component rendering a list of 100 items
async_list/maud_async_list
time: [2.3114 µs 2.3241 µs 2.3377 µs]
async_list/leptos_async_list
time: [55.149 µs 55.228 µs 55.315 µs]
async_list/rscx_async_list
time: [5.4809 µs 5.4987 µs 5.5151 µs]
I'll reiterate the disclaimer: Leptos is not specifically made for SSR. Going through its reactivity system (using async resources) adds overhead.