Can rust and serde-xml-rs parse comments from XML files?

Question

<foo>
  <!-- 2021-03-17 08:15:00 EST -->
  <row>
     <value>100</value>
  </row>
</foo>

I would like to get the comment from an XML file and was wondering if that was possible and if so how? I didn't see an example of that. In the above example, i would like to get "2021-03-17 08:15:00 EST"

Answer 1

No, at this time serde-xml-rs does not support parsing comments from XML files. See here in the source; they skip comments all together.

But there's an open pull request to add support for parsing comments.

So if you want to parse comments right now (with a disclaimer that this is not stable because you use somebody's github fork to do it) you could use the fork of the author of above pull request in this way:

// Cargo.toml contains:
//
// [dependencies]
// serde = {version = "1.0", features = ["derive"]}
// serde-xml-rs = {git = "https://github.com/elmarco/serde-xml-rs.git", branch = "comment"}

use serde::Deserialize;
use serde_xml_rs::from_reader;

#[derive(Debug, Deserialize)]
pub struct Foo {
    #[serde(rename = "$comment")]
    pub date: Option<String>,
    pub row: RowValue,
}

#[derive(Debug, Deserialize)]
pub struct RowValue {
    pub value: i32,
}

fn main() {
    let input = "<foo> \
                   <!-- 2021-03-17 08:15:00 EST --> \
                   <row> \
                      <value>100</value> \
                   </row> \
                 </foo>";

    let foo: Foo = from_reader(input.as_bytes()).unwrap();
    println!("input={:#?}", foo);
}