Deserialize Value into enum based on member variable

[kyrias]

Not sure if it's possible to do this in a nice way, but would be awesome if there was a way that didn't require manual deserialization. So, I'm trying to parse Matrix API responses, and one part of the JSON response has a content object that can look like this:

"content": {
    "body": "random text",
    "msgtype":"m.text"
}

But the actual fields in the object varies based on the msgtype field, so I want to have an enum with named fields and then deserialize into cases of this enum. Is it possible to do this in a nice way with serde?

[dtolnay]

We don't have something for this currently, but it would be a good candidate for a helper library. The other pattern that people commonly ask about is:

{
    "msgtype": "m.text",
    "content": {
        "body": "random text"
    }
}

#415 has a solution to that which you may be able to adapt to your case.

[kyrias]

Cool, I'll see if I can use that, thanks.

[dtolnay]

@kyrias as of Serde 0.9 this would be done with an internally tagged enum.

#[derive(Serialize, Deserialize)]
#[serde(tag = "msgtype")]
enum Kyrias {
    #[serde(rename = "m.text")]
    Text { body: String }

    /* other variants */
}