How to serde i64 with string by default?

[lz1998]

I want to serde i64 with string, but my struct is generated by prost, so I can't add #[serde(with = "string")].

[davidpdrsn]

Is this a question about axum or prost?

Regardless I suppose you can use https://docs.rs/prost-build/latest/prost_build/struct.Config.html#method.field_attribute or https://docs.rs/prost-build/latest/prost_build/struct.Config.html#method.type_attribute to add the attributes on the prost side.

[lz1998]

I have tried this, but it doesn't work, so I am trying to find some other methods to serde i64 with string by default. Maybe some axum serde global config.

    let mut cfg = prost_build::Config::new();
    cfg.type_attribute(".", "#[derive(serde::Serialize, serde::Deserialize)] #[serde(default)]");
    cfg.type_attribute("int64", "#[serde(with = \"string\")]");
    cfg.type_attribute(".int64", "#[serde(with = \"string\")]");
    cfg.type_attribute("i64", "#[serde(with = \"string\")]");
    cfg.type_attribute(".i64", "#[serde(with = \"string\")]");

[davidpdrsn]

I think you need to ask the prost people. I'm not familiar enough with prost to know.

Nothing axum specific should be necessary, and in fact can't override prost/serde stuff at all actually.

[lz1998]

If the struct is not generated by prost. Can I set a custom formatter for serde_json in axum?

serde-rs/json#833

[davidpdrsn]

If the struct is not generated by prost.

I mean you can do whatever you want 😊 axum doesn't care but also doesn't provide anything for you since its not specific to axum in any way.

Can I set a custom formatter for serde_json in axum?

I don't understand what you mean. Whats a formatter in the context of serde_json? You can write your own version of Json that implements IntoResponse makes the JSON output look different if thats what you mean.