[−][src]Crate webmachine_rust
webmachine-rust
Port of Webmachine-Ruby (https://github.com/webmachine/webmachine-ruby) to Rust.
webmachine-rust is a port of the Ruby version of webmachine. It implements a finite state machine for the HTTP protocol that provides semantic HTTP handling (based on the diagram from the webmachine project). It is basically a HTTP toolkit for building HTTP-friendly applications using the Hyper rust crate.
Webmachine-rust works with Hyper and sits between the Hyper Handler and your application code. It provides a resource struct with callbacks to handle the decisions required as the state machine is executed against the request with the following sequence.
REQUEST -> Hyper Handler -> WebmachineDispatcher -> WebmachineResource -> Your application code -> WebmachineResponse -> Hyper -> RESPONSE
Features
- Handles the hard parts of content negotiation, conditional requests, and response codes for you.
- Provides a resource struct with points of extension to let you describe what is relevant about your particular resource.
Missing Features
Currently, the following features from webmachine-ruby have not been implemented:
- Visual debugger
- Streaming response bodies
Implementation Deficiencies:
This implementation has the following deficiencies:
- Automatically decoding request bodies and encoding response bodies.
- No easy mechanism to generate bodies with different content types (e.g. JSON vs. XML).
- No easy mechanism for handling sub-paths in a resource.
- Dynamically determining the methods allowed on the resource.
Getting started with Hyper
Follow the getting started documentation from the Hyper crate to setup a Hyper service for your server.
You need to define a WebmachineDispatcher that maps resource paths to your webmachine resources (WebmachineResource).
Each WebmachineResource defines all the callbacks (via Closures) and values required to implement a resource.
The WebmachineDispatcher implementes the Hyper Service trait, so you can pass it to the make_service_fn
.
Note: This example uses the maplit crate to provide the btreemap
macro and the log crate for the logging macros.
use hyper::server::Server; use webmachine_rust::*; use webmachine_rust::context::*; use webmachine_rust::headers::*; use serde_json::{Value, json}; use std::io::Read; use std::net::SocketAddr; use hyper::service::make_service_fn; use std::convert::Infallible; // setup the dispatcher, which maps paths to resources. The requirement of make_service_fn is // that it has a static lifetime, so we can use lazy_static for that lazy_static!{ static ref DISPATCHER: WebmachineDispatcher<'static> = WebmachineDispatcher { routes: btreemap!{ "/myresource" => WebmachineResource { // Methods allowed on this resource allowed_methods: vec!["OPTIONS", "GET", "HEAD", "POST"], // if the resource exists callback resource_exists: callback(&|_, _| true), // callback to render the response for the resource render_response: callback(&|_, _| { let json_response = json!({ "data": [1, 2, 3, 4] }); Some(json_response.to_string()) }), // callback to process the post for the resource process_post: callback(&|_, _| /* Handle the post here */ Ok(true) ), // default everything else .. WebmachineResource::default() } } }; } async fn start_server() -> Result<(), String> { // Create a Hyper server that delegates to the dispatcher let addr = "0.0.0.0:8080".parse().unwrap(); let make_svc = make_service_fn(|_| async { Ok::<_, Infallible>(DISPATCHER.clone()) }); match Server::try_bind(&addr) { Ok(server) => { // start the actual server server.serve(make_svc).await; }, Err(err) => { error!("could not start server: {}", err); } }; Ok(()) }
Example implementations
For an example of a project using this crate, have a look at the Pact Mock Server from the Pact reference implementation.
Modules
content_negotiation | The |
context | The |
headers | The |
Macros
h | Simple macro to convert a string to a |
Structs
WebmachineDispatcher | The main hyper dispatcher |
WebmachineResource | Struct to represent a resource in webmachine |
Functions
callback | Wrap a callback in a structure that is safe to call between threads |
Type Definitions
WebmachineCallback | Type of a Webmachine resource callback |