1 files changed, 42 insertions, 0 deletions
diff --git a/components/style/parser.rs b/components/style/parser.rs
new file mode 100644
index 00000000000..6619ffd06dd
--- /dev/null
+++ b/components/style/parser.rs
@@ -0,0 +1,42 @@
+/* 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/. */
+
+
+use cssparser::{Parser, SourcePosition};
+use url::{Url, UrlParser};
+use log;
+
+use stylesheets::Origin;
+use namespaces::NamespaceMap;
+
+
+pub struct ParserContext<'a> {
+    pub stylesheet_origin: Origin,
+    pub base_url: &'a Url,
+    pub namespaces: NamespaceMap,
+}
+
+
+impl<'a> ParserContext<'a> {
+    pub fn in_user_agent_stylesheet(&self) -> bool {
+        self.stylesheet_origin == Origin::UserAgent
+    }
+
+    pub fn parse_url(&self, input: &str) -> Url {
+        UrlParser::new().base_url(self.base_url).parse(input)
+            .unwrap_or_else(|_| Url::parse("about:invalid").unwrap())
+    }
+}
+
+
+/// Defaults to a no-op.
+/// Set a `RUST_LOG=style::errors` environment variable
+/// to log CSS parse errors to stderr.
+pub fn log_css_error(input: &mut Parser, position: SourcePosition, message: &str) {
+    if log_enabled!(log::INFO) {
+        let location = input.source_location(position);
+        // TODO eventually this will got into a "web console" or something.
+        info!("{}:{} {}", location.line, location.column, message)
+    }
+}