#axum #htmx

axum-htmx

A set of htmx extractors, responders, and request guards for axum

6 releases (breaking)

0.5.0 Dec 3, 2023
0.4.0 Oct 24, 2023
0.3.1 Aug 16, 2023
0.3.0 Jul 29, 2023
0.1.0 Jul 22, 2023

#319 in Web programming

Download history 205/week @ 2023-10-29 273/week @ 2023-11-05 89/week @ 2023-11-12 242/week @ 2023-11-19 351/week @ 2023-11-26 304/week @ 2023-12-03 234/week @ 2023-12-10 656/week @ 2023-12-17 87/week @ 2023-12-24 113/week @ 2023-12-31 227/week @ 2024-01-07 260/week @ 2024-01-14 208/week @ 2024-01-21 259/week @ 2024-01-28 246/week @ 2024-02-04 434/week @ 2024-02-11

1,158 downloads per month

MIT/Apache

49KB
821 lines

axum-htmx


axum-htmx is a small extension library providing extractors, responders, and request guards for htmx headers within axum.

Table of Contents

Getting Started

Run cargo add axum-htmx to add the library to your project.

Extractors

All of the htmx request headers have a supported extractor. Extractors are infallible, meaning they will always succeed and never return an error. In the case where a header is not present, the extractor will return None or false dependant on the expected return type.

Header Extractor Value
HX-Boosted HxBoosted bool
HX-Current-URL HxCurrentUrl Option<axum::http::Uri>
HX-History-Restore-Request HxHistoryRestoreRequest bool
HX-Prompt HxPrompt Option<String>
HX-Request HxRequest bool
HX-Target HxTarget Option<String>
HX-Trigger-Name HxTriggerName Option<String>
HX-Trigger HxTrigger Option<String>

Responders

All of the htmx response headers have a supported responder. A responder is a basic type that implements IntoResponseParts, allowing you to simply and safely apply the HX-* headers to any of your responses.

Header Responder Value
HX-Location HxLocation axum::http::Uri
HX-Push-Url HxPushUrl axum::http::Uri
HX-Redirect HxRedirect axum::http::Uri
HX-Refresh HxRefresh bool
HX-Replace-Url HxReplaceUrl axum::http::Uri
HX-Reswap HxReswap axum_htmx::responders::SwapOption
HX-Retarget HxRetarget String
HX-Reselect HxReselect String
HX-Trigger HxResponseTrigger axum_htmx::serde::HxEvent
HX-Trigger-After-Settle HxResponseTrigger axum_htmx::serde::HxEvent
HX-Trigger-After-Swap HxResponseTrigger axum_htmx::serde::HxEvent

Request Guards

Requires features guards.

In addition to the extractors, there is also a route-wide layer request guard for the HX-Request header. This will redirect any requests without the header to "/" by default.

It should be noted that this is NOT a replacement for an auth guard. A user can trivially set the HX-Request header themselves. This is merely a convenience for preventing users from receiving partial responses without context. If you need to secure an endpoint you should be using a proper auth system.

Examples

Example: Extractors

In this example, we'll look for the HX-Boosted header, which is set when applying the hx-boost attribute to an element. In our case, we'll use it to determine what kind of response we send.

When is this useful? When using a templating engine, like minijinja, it is common to extend different templates from a _base.html template. However, htmx works by sending partial responses, so extending our _base.html would result in lots of extra data being sent over the wire.

If we wanted to swap between pages, we would need to support both full template responses and partial responses (as the page can be accessed directly or through a boosted anchor), so we look for the HX-Boosted header and extend from a _partial.html template instead.

use axum::response::IntoResponse;
use axum_htmx::HxBoosted;

async fn get_index(HxBoosted(boosted): HxBoosted) -> impl IntoResponse {
    if boosted {
        // Send a template extending from _partial.html
    } else {
        // Send a template extending from _base.html
    }
}

Example: Responders

We can trigger any event being listened to by the DOM using an htmx trigger header.

use axum_htmx::HxResponseTrigger;

// When we load our page, we will trigger any event listeners for "my-event.
async fn index() -> (&'static str, HxResponseTrigger) {
    (
        "Hello, world!",
        HxResponseTrigger::normal(["my-event", "second-event"]),
    )
}

htmx also allows arbitrary data to be sent along with the event, which we can use via the serde feature flag and the HxEvent type.

use serde_json::json;

// Note that we are using `HxResponseTrigger` from the `axum_htmx::serde` module
// instead of the root module.
use axum_htmx::{HxEvent, HxResponseTrigger};

async fn index() -> (&'static str, HxResponseTrigger) {
    let event = HxEvent::new_with_data(
        "my-event",
        // May be any object that implements `serde::Serialize`
        json!({"level": "info", "message": {
            "title": "Hello, world!",
            "body": "This is a test message.",
        }}),
    )
    .unwrap();

    ("Hello, world!", HxResponseTrigger::normal([event]))
}

Example: Router Guard

use axum::Router;
use axum_htmx::HxRequestGuardLayer;

fn router_one() -> Router {
    Router::new()
        // Redirects to "/" if the HX-Request header is not present
        .layer(HxRequestGuardLayer::default())
}

fn router_two() -> Router {
    Router::new()
        .layer(HxRequestGuardLayer::new("/redirect-to-this-route"))
}

Feature Flags

Flag Default Description Dependencies
guards Disabled Adds request guard layers. tower, futures-core, pin-project-lite
serde Disabled Adds serde support for the HxEvent and LocationOptions serde, serde_json

Contributing

Contributions are always welcome! If you have an idea for a feature or find a bug, let me know. PR's are appreciated, but if it's not a small change, please open an issue first so we're all on the same page!

License

axum-htmx is dual-licensed under either

at your option.

Dependencies

~1.7–2.6MB
~52K SLoC