Configure content disposition

Cargo.toml

@@ -57,6 +57,7 @@ unimplemented = "deny"
 unwrap_used = "warn"
 expect_used = "warn"
 type_complexity = "allow"
+len_without_is_empty = "allow"
 
 #
 # MARK: dependencies

crates/pile-dataset/src/serve/field.rs

@@ -18,6 +18,8 @@ pub struct FieldQuery {
 	source: String,
 	key: String,
 	path: String,
+	#[serde(default)]
+	download: bool,
 }
 
 /// Extract a specific field from an item's metadata
@@ -79,21 +81,38 @@ pub async fn get_field(
 		time_ms = start.elapsed().as_millis()
 	);
 
+	let disposition = if params.download {
+		"attachment"
+	} else {
+		"inline"
+	};
+
 	match value {
 		PileValue::String(s) => (
 			StatusCode::OK,
-			[(header::CONTENT_TYPE, "text/plain")],
+			[
+				(header::CONTENT_TYPE, "text/plain".to_owned()),
+				(header::CONTENT_DISPOSITION, disposition.to_owned()),
+			],
 			s.to_string(),
 		)
 			.into_response(),
 		PileValue::Blob { mime, bytes } => (
 			StatusCode::OK,
-			[(header::CONTENT_TYPE, mime.to_string())],
+			[
+				(header::CONTENT_TYPE, mime.to_string()),
+				(header::CONTENT_DISPOSITION, disposition.to_owned()),
+			],
 			bytes.as_ref().clone(),
 		)
 			.into_response(),
 		_ => match value.to_json(&state).await {
-			Ok(json) => (StatusCode::OK, Json(json)).into_response(),
+			Ok(json) => (
+				StatusCode::OK,
+				[(header::CONTENT_DISPOSITION, disposition.to_owned())],
+				Json(json),
+			)
+				.into_response(),
 			Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, format!("{e:?}")).into_response(),
 		},
 	}

crates/pile-dataset/src/serve/item.rs

@@ -19,6 +19,8 @@ use crate::Datasets;
 pub struct ItemQuery {
 	source: String,
 	key: String,
+	#[serde(default)]
+	download: bool,
 }
 
 /// Parse a `Range: bytes=...` header value.
@@ -161,11 +163,18 @@ pub async fn item_get(
 		StatusCode::OK
 	};
 
+	let disposition = if params.download {
+		"attachment"
+	} else {
+		"inline"
+	};
+
 	let mut builder = axum::http::Response::builder()
 		.status(status)
 		.header(header::CONTENT_TYPE, mime)
 		.header(header::ACCEPT_RANGES, "bytes")
-		.header(header::CONTENT_LENGTH, length);
+		.header(header::CONTENT_LENGTH, length)
+		.header(header::CONTENT_DISPOSITION, disposition);
 
 	if is_range {
 		builder = builder.header(