1 files changed, 90 insertions, 0 deletions
diff --git a/rsvg/src/iri.rs b/rsvg/src/iri.rs
new file mode 100644
index 00000000..e3272fe6
--- /dev/null
+++ b/rsvg/src/iri.rs
@@ -0,0 +1,90 @@
+//! CSS funciri values.
+
+use cssparser::Parser;
+
+use crate::document::NodeId;
+use crate::error::*;
+use crate::parsers::Parse;
+
+/// Used where style properties take a funciri or "none"
+///
+/// This is not to be used for values which don't come from properties.
+/// For example, the `xlink:href` attribute in the `<image>` element
+/// does not take a funciri value (which looks like `url(...)`), but rather
+/// it takes a plain URL.
+#[derive(Debug, Clone, PartialEq)]
+pub enum Iri {
+    None,
+    Resource(Box<NodeId>),
+}
+
+impl Iri {
+    /// Returns the contents of an `IRI::Resource`, or `None`
+    pub fn get(&self) -> Option<&NodeId> {
+        match *self {
+            Iri::None => None,
+            Iri::Resource(ref f) => Some(f),
+        }
+    }
+}
+
+impl Parse for Iri {
+    fn parse<'i>(parser: &mut Parser<'i, '_>) -> Result<Iri, ParseError<'i>> {
+        if parser
+            .try_parse(|i| i.expect_ident_matching("none"))
+            .is_ok()
+        {
+            Ok(Iri::None)
+        } else {
+            let loc = parser.current_source_location();
+            let url = parser.expect_url()?;
+            let node_id =
+                NodeId::parse(&url).map_err(|e| loc.new_custom_error(ValueErrorKind::from(e)))?;
+
+            Ok(Iri::Resource(Box::new(node_id)))
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_none() {
+        assert_eq!(Iri::parse_str("none").unwrap(), Iri::None);
+    }
+
+    #[test]
+    fn parses_url() {
+        assert_eq!(
+            Iri::parse_str("url(#bar)").unwrap(),
+            Iri::Resource(Box::new(NodeId::Internal("bar".to_string())))
+        );
+
+        assert_eq!(
+            Iri::parse_str("url(foo#bar)").unwrap(),
+            Iri::Resource(Box::new(NodeId::External(
+                "foo".to_string(),
+                "bar".to_string()
+            )))
+        );
+
+        // be permissive if the closing ) is missing
+        assert_eq!(
+            Iri::parse_str("url(#bar").unwrap(),
+            Iri::Resource(Box::new(NodeId::Internal("bar".to_string())))
+        );
+        assert_eq!(
+            Iri::parse_str("url(foo#bar").unwrap(),
+            Iri::Resource(Box::new(NodeId::External(
+                "foo".to_string(),
+                "bar".to_string()
+            )))
+        );
+
+        assert!(Iri::parse_str("").is_err());
+        assert!(Iri::parse_str("foo").is_err());
+        assert!(Iri::parse_str("url(foo)bar").is_err());
+    }
+}