1 files changed, 176 insertions, 0 deletions
diff --git a/components/script/dom/bindings/xmlname.rs b/components/script/dom/bindings/xmlname.rs
new file mode 100644
index 00000000000..e8a53707420
--- /dev/null
+++ b/components/script/dom/bindings/xmlname.rs
@@ -0,0 +1,176 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Functions for validating and extracting qualified XML names.
+
+use dom::bindings::error::{Error, ErrorResult, Fallible};
+use string_cache::{Atom, Namespace};
+use util::str::DOMString;
+
+/// Validate a qualified name. See https://dom.spec.whatwg.org/#validate for details.
+pub fn validate_qualified_name(qualified_name: &str) -> ErrorResult {
+    match xml_name_type(qualified_name) {
+        XMLName::InvalidXMLName => {
+            // Step 1.
+            Err(Error::InvalidCharacter)
+        },
+        XMLName::Name => {
+            // Step 2.
+            Err(Error::Namespace)
+        },
+        XMLName::QName => Ok(())
+    }
+}
+
+/// Validate a namespace and qualified name and extract their parts.
+/// See https://dom.spec.whatwg.org/#validate-and-extract for details.
+pub fn validate_and_extract(namespace: Option<DOMString>, qualified_name: &str)
+                            -> Fallible<(Namespace, Option<Atom>, Atom)> {
+    // Step 1.
+    let namespace = namespace_from_domstring(namespace);
+
+    // Step 2.
+    try!(validate_qualified_name(qualified_name));
+
+    let colon = ':';
+
+    // Step 5.
+    let mut parts = qualified_name.splitn(2, colon);
+
+    let (maybe_prefix, local_name) = {
+        let maybe_prefix = parts.next();
+        let maybe_local_name = parts.next();
+
+        debug_assert!(parts.next().is_none());
+
+        if let Some(local_name) = maybe_local_name {
+            debug_assert!(!maybe_prefix.unwrap().is_empty());
+
+            (maybe_prefix, local_name)
+        } else {
+            (None, maybe_prefix.unwrap())
+        }
+    };
+
+    debug_assert!(!local_name.contains(colon));
+
+    match (namespace, maybe_prefix) {
+        (ns!(""), Some(_)) => {
+            // Step 6.
+            Err(Error::Namespace)
+        },
+        (ref ns, Some("xml")) if ns != &ns!(XML) => {
+            // Step 7.
+            Err(Error::Namespace)
+        },
+        (ref ns, p) if ns != &ns!(XMLNS) &&
+                      (qualified_name == "xmlns" || p == Some("xmlns")) => {
+            // Step 8.
+            Err(Error::Namespace)
+        },
+        (ns!(XMLNS), p) if qualified_name != "xmlns" && p != Some("xmlns") => {
+            // Step 9.
+            Err(Error::Namespace)
+        },
+        (ns, p) => {
+            // Step 10.
+            Ok((ns, p.map(Atom::from_slice), Atom::from_slice(local_name)))
+        }
+    }
+}
+
+/// Results of `xml_name_type`.
+#[derive(PartialEq)]
+#[allow(missing_docs)]
+pub enum XMLName {
+    QName,
+    Name,
+    InvalidXMLName
+}
+
+/// Check if an element name is valid. See http://www.w3.org/TR/xml/#NT-Name
+/// for details.
+pub fn xml_name_type(name: &str) -> XMLName {
+    fn is_valid_start(c: char) -> bool {
+        match c {
+            ':' |
+            'A' ... 'Z' |
+            '_' |
+            'a' ... 'z' |
+            '\u{C0}' ... '\u{D6}' |
+            '\u{D8}' ... '\u{F6}' |
+            '\u{F8}' ... '\u{2FF}' |
+            '\u{370}' ... '\u{37D}' |
+            '\u{37F}' ... '\u{1FFF}' |
+            '\u{200C}' ... '\u{200D}' |
+            '\u{2070}' ... '\u{218F}' |
+            '\u{2C00}' ... '\u{2FEF}' |
+            '\u{3001}' ... '\u{D7FF}' |
+            '\u{F900}' ... '\u{FDCF}' |
+            '\u{FDF0}' ... '\u{FFFD}' |
+            '\u{10000}' ... '\u{EFFFF}' => true,
+            _ => false,
+        }
+    }
+
+    fn is_valid_continuation(c: char) -> bool {
+        is_valid_start(c) || match c {
+            '-' |
+            '.' |
+            '0' ... '9' |
+            '\u{B7}' |
+            '\u{300}' ... '\u{36F}' |
+            '\u{203F}' ... '\u{2040}' => true,
+            _ => false,
+        }
+    }
+
+    let mut iter = name.chars();
+    let mut non_qname_colons = false;
+    let mut seen_colon = false;
+    let mut last = match iter.next() {
+        None => return XMLName::InvalidXMLName,
+        Some(c) => {
+            if !is_valid_start(c) {
+                return XMLName::InvalidXMLName;
+            }
+            if c == ':' {
+                non_qname_colons = true;
+            }
+            c
+        }
+    };
+
+    for c in iter {
+        if !is_valid_continuation(c) {
+            return XMLName::InvalidXMLName;
+        }
+        if c == ':' {
+            match seen_colon {
+                true => non_qname_colons = true,
+                false => seen_colon = true
+            }
+        }
+        last = c
+    }
+
+    if last == ':' {
+        non_qname_colons = true
+    }
+
+    match non_qname_colons {
+        false => XMLName::QName,
+        true => XMLName::Name
+    }
+}
+
+/// Convert a possibly-null URL to a namespace.
+///
+/// If the URL is None, returns the empty namespace.
+pub fn namespace_from_domstring(url: Option<DOMString>) -> Namespace {
+    match url {
+        None => ns!(""),
+        Some(ref s) => Namespace(Atom::from_slice(s)),
+    }
+}