Derive Macro xso::FromXml

#[derive(FromXml)]
{
    // Attributes available to this derive:
    #[xml]
}

Make a struct or enum parseable from XML

This derives the FromXml trait on a struct or enum. It is the counterpart to IntoXml.

Example

#[derive(FromXml, Debug, PartialEq)]
#[xml(namespace = "urn:example", name = "foo")]
struct Foo;

let foo: Foo = xso::from_bytes(b"<foo xmlns='urn:example'/>").unwrap();
assert_eq!(foo, Foo);

Attributes

The derive macros need to know which XML namespace and name the elements it is supposed have. This must be specified via key-value pairs on the type the derive macro is invoked on. These are specified as Rust attributes. In order to disambiguate between XML attributes and Rust attributes, we are going to refer to Rust attributes using the term meta instead, which is consistent with the Rust language reference calling that syntax construct meta.

All key-value pairs interpreted by these derive macros must be wrapped in a #[xml( ... )] meta. The following keys are defined on structs:

Key	Value type	Description
namespace	string literal or path	The XML element namespace to match. If it is a path, it must point at a &'static str.
name	string literal or path	The XML element name to match. If it is a path, it must point at a &'static NcNameStr.

Note that the name value must be a valid XML element name, without colons. The namespace prefix, if any, is assigned automatically at serialisation time and cannot be overridden. The following will thus not compile:

#[derive(FromXml, Debug, PartialEq)]
#[xml(namespace = "urn:example", name = "fnord:foo")]  // colon not allowed
struct Foo;

Limitations

Supports only empty structs currently. For example, the following will not work:

#[derive(FromXml, Debug, PartialEq)]
#[xml(namespace = "urn:example", name = "foo")]
struct Foo {
    some_field: String,
}

Macro to derive a xso::FromXml implementation on a type.

The user-facing documentation for this macro lives in the xso crate.