//! Handling of `xlink:href` and `href` attributes

//!

//! In SVG1.1, links to elements are done with the `xlink:href` attribute.  However, SVG2

//! reduced this to just plain `href` with no namespace:

//! <https://svgwg.org/svg2-draft/linking.html#XLinkRefAttrs>

//!

//! If an element has both `xlink:href` and `href` attributes, the `href` overrides the

//! other.  We implement that logic in this module.

use markup5ever::{expanded_name, local_name, namespace_url, ns, ExpandedName};

/// Returns whether the attribute is either of `xlink:href` or `href`.

///

/// # Example

///

/// Use with an `if` pattern inside a `match`:

///

/// ```

/// # use markup5ever::{expanded_name, local_name, namespace_url, ns, QualName, Prefix, Namespace, LocalName, ExpandedName};

/// # use rsvg::doctest_only::{is_href,set_href};

///

/// let qual_name = QualName::new(

///     Some(Prefix::from("xlink")),

///     Namespace::from("http://www.w3.org/1999/xlink"),

///     LocalName::from("href"),

/// );

///

/// let value = "some_url";

/// let mut my_field: Option<String> = None;

///

/// match qual_name.expanded() {

///     ref name if is_href(name) => set_href(name, &mut my_field, Some(value.to_string())),

///     _ => unreachable!(),

/// }

/// ```

        *name,

        expanded_name!(xlink "href") | expanded_name!("", "href")

    )

/// Sets an `href` attribute in preference over an `xlink:href` one.

///

/// See [`is_href`] for example usage.

    }