tide-validator is a middleware working with Tide, a web framework in Rust which let you validate your data coming from a request. You'll be able to create custom validators to validate your HTTP parameters, query parameters, cookies and headers.
- Custom validators: you can chain multiple validators and develop a custom validator is very easy. It's just a closure.
- Validate everything: with the enum
HttpFieldyou can validate different fields like cookies, headers, query parameters and parameters. - Your own errors: thanks to generics in Rust you can use your own custom error when the data is invalid. need.
To create your own validator it's just a closure to create with this form:
// The first closure's parameter is the parameter/queryparameter/cookie/header name.
// The second parameter is the value of this HTTP element.
// None means the field doesn't exist in the request (useful to force specific fields to be required).
Fn(&str, Option<&str>) -> Result<(), T> + Send + Sync + 'static where T: Serialize + Send + Sync + 'staticThe full documentation is available here
- simple validation
// Our own validator is a simple closure to check if the field is a number
fn is_number(field_name: &str, field_value: Option<&str>) -> Result<(), String> {
if let Some(field_value) = field_value {
if field_value.parse::<i64>().is_err() {
return Err(format!("field '{}' = '{}' is not a valid number", field_name, field_value));
}
}
Ok(())
}
//... in main function
let mut app = tide::new();
let mut validator_middleware = ValidatorMiddleware::new();
// 'age' is the parameter name inside the route '/test/:age'
validator_middleware.add_validator(HttpField::Param("age"), is_number);
// You can assign different middleware for each routes therefore different validators for each routes
app.at("/test/:age")
.middleware(validator_middleware)
.get(|_: tide::Request<()>| async move {
let cat = Cat {
name: "Gribouille".into(),
};
tide::Response::new(StatusCode::Ok).body_json(&cat).unwrap()
});
app.listen("127.0.0.1:8080").await?;- chain multiple validators
// This validator force element to be required
fn is_required(field_name: &str, field_value: Option<&str>) -> Result<(), String> {
if field_value.is_none() {
Err(format!("'{}' is required", field_name))
} else {
Ok(())
}
}
// ... your main function
let mut app = tide::new();
let mut validator_middleware = ValidatorMiddleware::new();
// Here 'age' is a query parameter, the validator stay the same as in previous example
validator_middleware.add_validator(HttpField::QueryParam("age"), is_number);
// You can also add multiple validators on a single query parameter to check different things
validator_middleware.add_validator(HttpField::QueryParam("age"), is_required);
// You can assign different middleware for each routes therefore different validators for each routes
app.at("/test")
.middleware(validator_middleware)
.get(|_: tide::Request<()>| async move {
let cat = Cat {
name: "Mozart".into(),
};
tide::Response::new(StatusCode::Ok).body_json(&cat).unwrap()
},
);
app.listen("127.0.0.1:8080").await?;- Use your own custom error
// Your custom error which your api will send if an error occurs
#[derive(Debug, Serialize)]
struct CustomError {
status_code: usize,
message: String,
}
// Your validator can also return your own error type
fn is_number(field_name: &str, field_value: Option<&str>) -> Result<(), CustomError> {
if let Some(field_value) = field_value {
if field_value.parse::<i64>().is_err() {
return Err(CustomError {
status_code: 400,
message: format!(
"field '{}' = '{}' is not a valid number",
field_name, field_value
),
});
}
}
Ok(())
}
// ... your main function- Dynamic validators
// Validator inside a function as a closure to be dynamic with max_length
fn is_length_under(
max_length: usize,
) -> Box<dyn Fn(&str, Option<&str>) -> Result<(), CustomError> + Send + Sync + 'static> {
Box::new(
move |field_name: &str, field_value: Option<&str>| -> Result<(), CustomError> {
if let Some(field_value) = field_value {
if field_value.len() > max_length {
let my_error = CustomError {
status_code: 400,
message: format!(
"element '{} which is equals to '{}' have not the maximum length of {}",
field_name, field_value, max_length
),
};
return Err(my_error);
}
}
Ok(())
},
)
}
// Simply call it on a cookie `session` for example:
validator_middleware.add_validator(HttpField::Cookie("session"), is_length_under(20));