The dxr project provides crates for writing XML-RPC API clients and servers in Rust.
Documentation of the public API and a tutorial-style introduction are available on
the docs.rs page for this crate. Additionally, there are a few
example binaries in the examples
folder.
The following features are already implemented:
- (de)serialization support for converting XML-RPC XML strings into strongly-typed Rust values
- conversion traits between XML-RPC values and Rust primitives, arrays, slices, byte arrays, tuples, hashmaps, and custom structs (via derive macros)
- built-in XML-escaping and un-escaping of string arguments
- built-in date & time parsing for the
dateTime.iso8861
value type - built-in base64 en- and decoding of byte vectors for the
base64
type - optional support for the (non-standard)
<i8>
(64-bit unsigned integer) and<nil/>
(enabled by default) - support for arbitrary method call argument types without needing to convert values first (for up to 8 arguments; support for more could be implemented, if needed)
- basic support for both XML-RPC clients (with
reqwest
) and servers (withaxum
)
All conversion methods (both between Rust XML-RPC values and XML strings, and between
Rust primitives and Rust XML-RPC values) are extensively checked for correctness by unit
tests and property-based tests using quickcheck
.
The project is split into three crates:
dxr
: high-level method call, client, and server implementationsdxr_derive
:ToDXR
andFromDXR
derive macros for custom structsdxr_shared
: definition of conversion traits and XML-RPC types for (de)serialization
All relevant parts of dxr_derive
and dxr_shared
are re-exported in the dxr
crate,
they are not supposed to be used directly.
Searching for xml-rpc
on crates.io yields a few results, but they all did not fit my
use case, or were very hard to use. Either they didn't support implementing both clients
and servers, or no easy conversion methods from Rust types to XML-RPC types was available.
And none of the crates supports (de)serializing both Rust types and custom user-defined
types by using derive macros.
Because of this state of the XML-RPC crate ecosystem in Rust, the defining purpose of the
dxr
crate is that it should be opinionated, but also very easy to use, for implementing
both XML-RPC clients and servers, with first-class support for (de)serializing custom
types, in addition to built-in support for transparently converting Rust primitives to
XML-RPC values.
Additionally, the crate is built on top of best-in-class (in my opinion) libraries for
(de)serializing XML (quick-xml
), HTTP client side (reqwest
), HTTP server side
(axum
).
The /examples/
directory contains implementations of two simple clients and a simple
server for demonstration purposes. They use the tokio
runtime, which works great with
both reqwest
and axum
.
Note that the amount of code that is required for writing simple XML-RPC clients and
servers is very small. The client
example has only ~10 LOC, and the server
example
only needs ~15 LOC, but both examples even include error handling.