Trait apisdk::JsonExtractor

source ·

pub trait JsonExtractor {
    // Required method
    fn try_extract<T>(self) -> ApiResult<T>
       where T: DeserializeOwned;

    // Provided method
    fn require_headers() -> bool { ... }
}

Expand description

This trait is used to extract result from response.

§Usage

let req = client.get("/api/path").await?;
let res = send!(req, TypeOfExtractor).await?;

§Examples

§Check return code

#[derive(serde::Deserialize)]
pub struct CheckReturnCode(serde_json::Value);

impl JsonExtractor for CheckReturnCode {
    fn try_extract(self) -> ApiResult<T> {
        match self.0.get("ret_code").and_then(|c| c.as_i64()) {
            Some(0) => serde_json::from_value(self.0).map_err(|e| e.into()),
            Some(c) => Err(ApiError::BusinessError(c, Some("Invalid ret_code".to_string()))),
            None => Err(ApiError::BusinessError(-1, Some("No ret_code".to_string()))),
        }
    }
}

§Extract single field

#[derive(serde::Deserialize)]
pub struct ExtractData {
    data: serde_json::Value
}

impl JsonExtractor for ExtractData {
    fn try_extract(self) -> ApiResult<T> {
        serde_json::from_value(self.data).map_err(|e| e.into())
    }
}

§Built-in JsonExtractors

std::string::String
- treat whole payload as text output
serde_json::Value
- treat whole payload as json output
apisdk::WholePayload
- an alias of serde_json::Value
apisdk::CodeDataMessage
- parse {code, data, message} json payload, and return data field