Using CORS Library Functions

use pdk::*;
use pdk::cors;

#[entrypoint]
async fn configure(launcher: Launcher) -> Result<(), LaunchError> {

    let cors_configuration = create_cors_configuration();

    let filter = on_request(|rs| request_filter(rs, &cors_configuration))
        .on_response(response_filter);

    launcher.launch(filter).await
}
rust✓ Copied

async fn request_filter(
    request_headers_state: RequestHeadersState,
    cors_configuration: &cors::Configuration<'_>,
) -> Flow<Vec<(String, String)>> {

    // Create a new CORS checker.
    let cors = cors::Cors::new(cors_configuration);

    let request_headers = request_headers_state.handler().headers();

    let cors_result = cors.check(&request_headers);

    match cors_result {

        // The CORS validation was succesful.
        Ok(cors_check) => match cors_check.response_type() {

            // A CORS preflight fetch was requested, return an early response.
            cors::ResponseType::Preflight => {
                Flow::Break(Response::new(200).with_headers(check.into_headers()))
            }

            // This is a CORS main request, continue and pass the headers to the response.
            cors::ResponseType::Main => {
                logger::info!("Main CORS response.");
                Flow::Continue(check.into_headers())
            }
        },

        // The CORS validation failed. The request must be refused.
        Err(cors_error) => {
            Flow::Break(Response::new(200))
        }
    }
}
rust✓ Copied
Expand content

async fn response_filter(state: ResponseHeadersState, data: RequestData<Vec<(String, String)>>) {

    // Take the headers to add from the request data.
    let RequestData::Continue(headers_to_add) = data else {
        return;
    };

    // Add the headers to the response
    for (name, value) in headers_to_add.iter() {
        state.handler().set_header(name, value);
    }
}
rust✓ Copied