From e3ba866b8cd8e83a2d0831945c4f389529ebfcdc Mon Sep 17 00:00:00 2001
From: Jim O'Donnell <james.odonnell@dtc.ox.ac.uk>
Date: Mon, 14 Oct 2024 12:32:48 +0100
Subject: [PATCH] refactor(frontend): refactor DataMap component (#157)

Refactor the helper functions, which render the DeckGL layers, and move the `dataLoadTrigger` logic into a `useTrigger` hook.
---
 frontend/src/lib/data-map/DataMap.tsx | 73 +++++++++++++++------------
 1 file changed, 40 insertions(+), 33 deletions(-)

diff --git a/frontend/src/lib/data-map/DataMap.tsx b/frontend/src/lib/data-map/DataMap.tsx
index de40a11..f5ccf25 100644
--- a/frontend/src/lib/data-map/DataMap.tsx
+++ b/frontend/src/lib/data-map/DataMap.tsx
@@ -1,6 +1,6 @@
 import type { MapboxOverlay } from '@deck.gl/mapbox/typed';
 import { useMap } from 'react-map-gl/maplibre';
-import { FC, useCallback, useMemo, useRef } from 'react';
+import { FC, useMemo, useRef } from 'react';
 
 import { useInteractions } from 'lib/state/interactions/use-interactions';
 import { useTriggerMemo } from 'lib/hooks/use-trigger-memo';
@@ -15,16 +15,31 @@ function lookupViewForDeck(deckLayerId: string) {
   return deckLayerId.split('@')[0];
 }
 
-export const DataMap: FC<{
-  firstLabelId: string;
-  interactionGroups: Map<string, InteractionGroupConfig>;
-  viewLayers: ViewLayer[];
-  viewLayersParams: Record<string, ViewLayerParams>;
-}> = ({ firstLabelId, interactionGroups, viewLayers, viewLayersParams }) => {
-  const deckRef = useRef<MapboxOverlay>();
-  const { current: map } = useMap();
-  const zoom = map.getMap().getZoom();
+function makeDeckLayers(
+  viewLayer: ViewLayer,
+  viewLayerParams: ViewLayerParams,
+  zoom: number,
+  beforeId: string | undefined,
+) {
+  return viewLayer.fn({
+    deckProps: { id: viewLayer.id, pickable: !!viewLayer.interactionGroup, beforeId },
+    zoom,
+    ...viewLayerParams,
+  });
+}
+
+function buildLayers(
+  viewLayers: ViewLayer[],
+  viewLayersParams: Record<string, ViewLayerParams>,
+  zoom: number,
+  beforeId: string | undefined,
+) {
+  return viewLayers.map((viewLayer) =>
+    makeDeckLayers(viewLayer, viewLayersParams[viewLayer.id], zoom, beforeId),
+  ) as LayersList;
+}
 
+function useTrigger(viewLayers: ViewLayer[]) {
   const dataLoaders = useMemo(
     () =>
       viewLayers
@@ -33,15 +48,20 @@ export const DataMap: FC<{
     [viewLayers],
   );
 
-  const dataLoadTrigger = useDataLoadTrigger(dataLoaders);
+  return useDataLoadTrigger(dataLoaders);
+}
 
-  const layersFunction = useCallback(
-    ({ zoom }: { zoom: number }) =>
-      viewLayers.map((viewLayer) =>
-        makeDeckLayers(viewLayer, viewLayersParams[viewLayer.id], zoom, firstLabelId),
-      ) as LayersList,
-    [firstLabelId, viewLayers, viewLayersParams],
-  );
+export const DataMap: FC<{
+  firstLabelId: string;
+  interactionGroups: Map<string, InteractionGroupConfig>;
+  viewLayers: ViewLayer[];
+  viewLayersParams: Record<string, ViewLayerParams>;
+}> = ({ firstLabelId, interactionGroups, viewLayers, viewLayersParams }) => {
+  const deckRef = useRef<MapboxOverlay>();
+  const { current: map } = useMap();
+  const zoom = map.getMap().getZoom();
+
+  const dataLoadTrigger = useTrigger(viewLayers);
 
   const { onHover, onClick, layerFilter, pickingRadius } = useInteractions(
     viewLayers,
@@ -50,8 +70,8 @@ export const DataMap: FC<{
   );
 
   const layers = useTriggerMemo(
-    () => layersFunction({ zoom }),
-    [layersFunction, zoom],
+    () => buildLayers(viewLayers, viewLayersParams, zoom, firstLabelId),
+    [viewLayers, viewLayersParams, zoom, firstLabelId],
     dataLoadTrigger,
   );
 
@@ -71,16 +91,3 @@ export const DataMap: FC<{
     />
   );
 };
-
-function makeDeckLayers(
-  viewLayer: ViewLayer,
-  viewLayerParams: ViewLayerParams,
-  zoom: number,
-  beforeId: string | undefined,
-) {
-  return viewLayer.fn({
-    deckProps: { id: viewLayer.id, pickable: !!viewLayer.interactionGroup, beforeId },
-    zoom,
-    ...viewLayerParams,
-  });
-}