Trait FromParam

pub trait FromParam: Sized {
    // Required method
    fn from_param(value: &str) -> Result<Self, FrameworkError>;
}

Expand description

Trait for types that can be extracted from a single path parameter

This trait enables automatic extraction of typed values from route parameters like /users/{id} where {id} can be extracted as an i32.

§Example

The #[handler] macro uses this trait to transform:

#[handler]
pub async fn show(id: i32, slug: String) -> Response {
    // ...
}

Into code that extracts id and slug from the route parameters.

Extract Self from a string parameter value

Returns Err(FrameworkError) if extraction fails, which will be converted to an appropriate HTTP error response (400 Bad Request).

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.