Merge pull request #555 from kivikakk/context-user

html: add user data to context.

Author: kivikakk

examples/custom_formatter_user.rs

@@ -0,0 +1,47 @@
+use comrak::html::ChildRendering;
+use comrak::{create_formatter, nodes::NodeValue};
+use std::io::Write;
+
+create_formatter!(CustomFormatter<usize>, {
+    NodeValue::Emph => |context, entering| {
+        context.user += 1;
+        if entering {
+            context.write_all(b"<i>")?;
+        } else {
+            context.write_all(b"</i>")?;
+        }
+    },
+    NodeValue::Strong => |context, entering| {
+        context.user += 1;
+        context.write_all(if entering { b"<b>" } else { b"</b>" })?;
+    },
+    NodeValue::Image(ref nl) => |context, node, entering| {
+        assert!(node.data.borrow().sourcepos == (3, 1, 3, 18).into());
+        if entering {
+            context.write_all(nl.url.to_uppercase().as_bytes())?;
+        }
+        return Ok(ChildRendering::Skip);
+    },
+});
+
+fn main() {
+    use comrak::{parse_document, Arena, Options};
+
+    let options = Options::default();
+    let arena = Arena::new();
+    let doc = parse_document(
+        &arena,
+        "_Hello_, **world**.\n\n![title](/img.png)",
+        &options,
+    );
+
+    let mut buf: Vec<u8> = vec![];
+    let converted_count = CustomFormatter::format_document(doc, &options, &mut buf, 0).unwrap();
+
+    assert_eq!(
+        std::str::from_utf8(&buf).unwrap(),
+        "<p><i>Hello</i>, <b>world</b>.</p>\n<p>/IMG.PNG</p>\n"
+    );
+
+    assert_eq!(converted_count, 4);
+}