From 8df59be1d514287e6323aa619ce69a76ce297d3b Mon Sep 17 00:00:00 2001
From: 0HyperCube <78500760+0HyperCube@users.noreply.github.com>
Date: Mon, 15 Jan 2024 06:18:08 +0000
Subject: [PATCH] Display graph errors in the viewport (#1577)

* Display graph errors in the viewport

* Polish up the styling

* Clear click targets while graph can't be rendered

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>
---
 .../messages/portfolio/portfolio_message_handler.rs   | 11 +++++++++++
 editor/src/node_graph_executor.rs                     |  7 ++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/editor/src/messages/portfolio/portfolio_message_handler.rs b/editor/src/messages/portfolio/portfolio_message_handler.rs
index 433862db..2d52e282 100644
--- a/editor/src/messages/portfolio/portfolio_message_handler.rs
+++ b/editor/src/messages/portfolio/portfolio_message_handler.rs
@@ -634,6 +634,17 @@ impl PortfolioMessageHandler {
 
 		self.executor.poll_node_graph_evaluation(active_document, responses).unwrap_or_else(|e| {
 			log::error!("Error while evaluating node graph: {e}");
+
+			let error = r#"
+				<rect x="50%" y="50%" width="480" height="100" transform="translate(-240 -50)" rx="4" fill="var(--color-error-red)" />
+				<text x="50%" y="50%" dominant-baseline="middle" text-anchor="middle" font-size="18" fill="var(--color-2-mildblack)">
+					<tspan x="50%" dy="-24" font-weight="bold">The document cannot be rendered in its current state.</tspan>
+					<tspan x="50%" dy="24">Check for error details in the node graph, which can be</tspan>
+					<tspan x="50%" dy="24">opened with the viewport's top right <tspan font-style="italic">Node Graph</tspan> button.</tspan>
+				/text>"#
+				// It's a mystery why the `/text>` tag above needs to be missing its `<`, but when it exists it prints the `<` character in the text. However this works with it removed.
+				.to_string();
+			responses.add(FrontendMessage::UpdateDocumentArtwork { svg: error });
 		});
 	}
 }
diff --git a/editor/src/node_graph_executor.rs b/editor/src/node_graph_executor.rs
index 254d220b..3241f4f0 100644
--- a/editor/src/node_graph_executor.rs
+++ b/editor/src/node_graph_executor.rs
@@ -558,7 +558,12 @@ impl NodeGraphExecutor {
 					responses.add(BroadcastEvent::DocumentIsDirty);
 					responses.add(OverlaysMessage::Draw);
 
-					let node_graph_output = result.map_err(|e| format!("Node graph evaluation failed: {e:?}"))?;
+					let Ok(node_graph_output) = result else {
+						// Clear the click targets while the graph is in an un-renderable state
+						document.metadata.update_click_targets(HashMap::new());
+
+						return Err("Node graph evaluation failed".to_string());
+					};
 
 					document.metadata.update_transforms(new_upstream_transforms);
 					document.metadata.update_click_targets(new_click_targets);