Add visualization stuff using GraphViz at /api/visualize

server/src/web.rs

@@ -1,6 +1,8 @@
 use std::{
     borrow::Cow,
     collections::HashMap,
+    io::Write,
+    process::{Command, Stdio},
     sync::{mpsc, Arc},
 };
 
@@ -17,6 +19,7 @@ use crate::{
     session_id::SessionId,
     project::InstanceProjectNodeMetadata,
     rbx_snapshot::InstanceChanges,
+    visualize_tree::VisualizeTree,
 };
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -160,6 +163,29 @@ impl Server {
                 })
             },
 
+            (GET) (/api/visualize) => {
+                let rbx_session = self.session.rbx_session.lock().unwrap();
+                let tree = rbx_session.get_tree();
+
+                let dot_source = format!("{}", VisualizeTree(tree));
+
+                let mut child = Command::new("dot")
+                    .arg("-Tsvg")
+                    .stdin(Stdio::piped())
+                    .stdout(Stdio::piped())
+                    .spawn()
+                    .expect("Failed to spawn GraphViz process -- make sure it's installed in order to use /api/visualize");
+
+                {
+                    let stdin = child.stdin.as_mut().expect("Failed to open stdin");
+                    stdin.write_all(dot_source.as_bytes()).expect("Failed to write to stdin");
+                }
+
+                let output = child.wait_with_output().expect("Failed to read stdout");
+
+                Response::svg(String::from_utf8_lossy(&output.stdout))
+            },
+
             _ => Response::empty_404()
         )
     }