Easy-to-use REST client for Rust programming language that provides automatic serialization and deserialization from Rust structs. The library is implemented using Hyper and Serde JSON.
Add the following lines to your project Cargo.toml file:
toml
[dependencies]
restson = "^0.1"
serde = "^1.0"
serde_derive = "^1.0"
This adds dependencies for the Restson library and also for Serde which is needed to derive Serialize and Deserialize for user defined data structures.
Next, the data structures for the REST interface should be defined. The struct fields need to match with the API JSON fields. The whole JSON does not need to be defined, the struct can also contain a subset of the fields. Structs that are used with GET should derive Deserialize and structs that are used with POST should derive Serialize.
Example JSON (subset of http://httpbin.org/anything response):
json
{
"method": "GET",
"origin": "1.2.3.4",
"url": "https://httpbin.org/anything"
}
Corresponding Rust struct:
```rust
extern crate serde_derive;
struct HttpBinAnything { method: String, url: String, } ```
These definitions allow to automatically serialize/deserialize the data structures to/from JSON when requests are processed. For more complex scenarios, see the Serde examples.
In Restson library the API resource paths are associated with types. That is, the URL is constructed automatically and not given as parameter to requests. This allows to easily parametrize the paths without manual URL processing and reduces URL literals in the code.
Each type that is used with get/post needs to implement RestPath trait. The trait can be implemented multiple times with different generic parameters for the same type as shown below. The get_path can also return error to indicate that the parameters were not valid. This error is propagated directly to the client caller.
```rust
// plain API call without parameters
impl RestPath<()> for HttpBinAnything {
fn getpath(: ()) -> Result
// API call with one u32 parameter (e.g. "http://httpbin.org/anything/1234")
impl RestPath
To run requests the client instance needs to be created first. The base URL of the resource is given as parameter:
rust
let mut client = RestClient::new("http://httpbin.org").unwrap();
The following snippet shows an example GET request:
rust
// Gets https://httpbin.org/anything/1234 and deserializes the JSON to data variable
let data: HttpBinAnything = client.get(1234).unwrap();
The get and post functions call the get_path function automatically from RestPath based on the parameter type to construct the URL. If the compiler is able to infer the parameter and return value types from the context (as shown above), they do not need to be annotated. The call above is equivalent with:
rust
let data = client.get::<u32, HttpBinAnything>(1234).unwrap();
Restson also provides get_with function which is similar to the basic get but it also accepts additional query parameters that are added to the request URL.
rust
// Gets http://httpbin.org/anything/1234?a=2&b=abcd
let query = vec![("a","2"), ("b","abcd")];
let data: HttpBinAnything = client.get_with(1234, &query).unwrap();
Both GET interfaces return Result<T, Error> where T is the target type in which the returned JSON is deserialized to.
The following snippets show an example POST request:
```rust
struct HttpBinPost { data: String, }
impl RestPath<()> for HttpBinPost {
fn getpath(: ()) -> Result
rust
let data = HttpBinPost { data: String::from("test data")};
// Posts data to http://httpbin.org/post
client.post((), &data).unwrap();
``
In addition to the basicpostinterface, it is also possible to provide query parameters withpostwithfunction. Also,postcaptureandpostcapturewith` interfaces allow to capture and deserialize the message body returned by the server in the POST request.
The library uses the log crate to provide debug and trace logs. These logs allow to easily see both outgoing requests as well as incoming responses from the server. See the log crate documentation for details.
For more examples see tests directory.
The library is released under the MIT license. See LICENSE for details.