is there a way to iterate over key, values in a map

[sassman]

For a custom function, that accepts a minijinja::value::Value which holds a map, I would like to access the key, values of the inner map and even mutate the values or add new key, value pairs.

As it seems right one can only check for specific keys, via .get_attr(&str) but not iterate over all contents.

Maybe I'm missing something, in that case I would appreciate some input.

[mitsuhiko]

That is currently somewhat intentional. What you can do today is to use serde to serialize the value into something else. That's obviously not entirely ideal, but might be what you actually need. Can you share what you are trying to do? I'm happy to try to figure out an API to iterate over values and to expose the maps (in some form), but for that it would be interesting to understand the intended use.

[sassman]

Nice idea, I was able to go via serde_json::from_str into a HashMap<String, serde_json::Value>.
The HashMap is then mutable and all works well. The double serialization is right now not ideal, but also not a big issue in my case.

The example looks something like this:

pub fn jwt(_state: &State, claims: Value, signing_key: Option<Value>) -> Result<String, Error> {
    let mut claims: HashMap<String, serde_json::Value> =
        serde_json::from_str(claims.to_string().as_str()).unwrap();

    // in case the expiry is missing, we expire it in 15min
    if claims.contains_key(EXPIRY).not() {
        let expire_in = Utc::now()
            .add(Duration::minutes(15))
            .with_second(0)
            .unwrap()
            .timestamp();
        claims.insert(EXPIRY.to_string(), serde_json::Value::from(expire_in));
    }

    let token = jsonwebtoken::encode(
        &Header::default(),
        &claims,
        &EncodingKey::from_secret(b"secret"),
    );

    token.map_err(|e| {
        Error::new(
            ErrorKind::UndefinedError,
            "jsonwebtoken failed to encode the token.",
        )
        .with_source(e)
    })
}

[sassman]

Thanks a lot @mitsuhiko ❤️