Allow rendering the event/span target (#11)

Author: oli-obk

Cargo.toml

@@ -5,6 +5,8 @@ authors = ["David Barsky <me@davidbarsky.com>", "Nathan Whitaker"]
 edition = "2018"
 license = "MIT OR Apache-2.0"
 description = "a tracing layer that represents prints a heirarchal tree of spans and events."
+repository = "https://github.com/davidbarsky/tracing-tree"
+readme = "README.md"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

examples/basic.rs

@@ -5,7 +5,8 @@ use tracing_tree::HierarchicalLayer;
 fn main() {
     let layer = HierarchicalLayer::default()
         .with_indent_lines(true)
-        .with_indent_amount(2);
+        .with_indent_amount(2)
+        .with_targets(true);
 
     let subscriber = Registry::default().with(layer);
     tracing::subscriber::set_global_default(subscriber).unwrap();

src/format.rs

@@ -14,9 +14,14 @@ const LINE_BRANCH: &str = "├";
 
 #[derive(Debug)]
 pub struct Config {
+    /// Whether to use colors.
     pub ansi: bool,
+    /// Whether an ascii art tree is used or (if false) whether to just use whitespace indent
     pub indent_lines: bool,
+    /// The amount of chars to indent.
     pub indent_amount: usize,
+    /// Whether to show the module paths.
+    pub targets: bool,
 }
 
 impl Config {
@@ -30,6 +35,10 @@ impl Config {
             ..self
         }
     }
+
+    pub fn with_targets(self, targets: bool) -> Self {
+        Self { targets, ..self }
+    }
 }
 
 impl Default for Config {
@@ -38,6 +47,7 @@ impl Default for Config {
             ansi: true,
             indent_lines: false,
             indent_amount: 2,
+            targets: false,
         }
     }
 }

src/lib.rs

@@ -58,6 +58,7 @@ impl Default for HierarchicalLayer {
         let config = Config {
             ansi,
             indent_amount,
+            targets: false,
             ..Default::default()
         };
         Self {
@@ -88,6 +89,7 @@ impl<W> HierarchicalLayer<W>
 where
     W: MakeWriter + 'static,
 {
+    /// Enables terminal colors, boldness and italics.
     pub fn with_ansi(self, ansi: bool) -> Self {
         Self {
             config: self.config.with_ansi(ansi),
@@ -114,13 +116,23 @@ where
         Self { config, ..self }
     }
 
+    /// Renders an ascii art tree instead of just using whitespace indentation.
     pub fn with_indent_lines(self, indent_lines: bool) -> Self {
         Self {
             config: self.config.with_indent_lines(indent_lines),
             ..self
         }
     }
 
+    /// Whether to render the event and span targets. Usually targets are the module path to the
+    /// event/span macro invocation.
+    pub fn with_targets(self, targets: bool) -> Self {
+        Self {
+            config: self.config.with_targets(targets),
+            ..self
+        }
+    }
+
     fn styled(&self, style: Style, text: impl AsRef<str>) -> String {
         if self.config.ansi {
             style.paint(text.as_ref()).to_string()
@@ -173,6 +185,16 @@ where
 
         let indent = ctx.scope().count().saturating_sub(1);
 
+        if self.config.targets {
+            let target = span.metadata().target();
+            write!(
+                &mut current_buf,
+                "{}::",
+                self.styled(Style::new().dimmed(), target,),
+            )
+            .expect("Unable to write to buffer");
+        }
+
         write!(
             current_buf,
             "{name}",
@@ -249,6 +271,17 @@ where
             level.to_string()
         };
         write!(&mut event_buf, "{level}", level = level).expect("Unable to write to buffer");
+
+        if self.config.targets {
+            let target = event.metadata().target();
+            write!(
+                &mut event_buf,
+                " {}",
+                self.styled(Style::new().dimmed(), target,),
+            )
+            .expect("Unable to write to buffer");
+        }
+
         let mut visitor = FmtEvent {
             comma: false,
             bufs: &mut bufs,