Optimize rerenders

react.html

common.ts

variables.ts

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1" />
    <script crossorigin src="https://cdn.jsdelivr.net/npm/react@17/umd/react.production.min.js"></script>
    <script crossorigin src="https://cdn.jsdelivr.net/npm/react-dom@17/umd/react-dom.production.min.js"></script>
    <script crossorigin src="https://cdn.jsdelivr.net/npm/@babel/standalone@7/babel.min.js"></script>
    <!-- To make the map appear, you must add your apikey -->
    <script src="https://js.api.mappable.world/v3/?apikey=<YOUR_APIKEY>&lang=en_US" type="text/javascript"></script>

    <script
      data-plugins="transform-modules-umd"
      data-presets="typescript"
      type="text/babel"
      src="../variables.ts"
    ></script>
    <script
      data-plugins="transform-modules-umd"
      data-presets="typescript"
      type="text/babel"
      src="./common.ts"
    ></script>
    <script data-plugins="transform-modules-umd" data-presets="react, typescript" type="text/babel">
      import {CITY_1, CITY_2} from '../variables';
      import type {LngLat} from '@mappable-world/mappable-types';

      window.map = null;

      main();
      async function main() {
          // For each object in the JS API, there is a React counterpart
          // To use the React version of the API, include the module @mappable-world/mappable-reactify
          const [mappableReact] = await Promise.all([mappable.import('@mappable-world/mappable-reactify'), mappable.ready]);
          const reactify = mappableReact.reactify.bindTo(React, ReactDOM);
          const {MMap, MMapDefaultSchemeLayer, MMapDefaultFeaturesLayer, MMapControls, MMapControlButton} =
              reactify.module(mappable);

          const {MMapZoomControl, MMapDefaultMarker} = reactify.module(
              await mappable.import('@mappable-world/mappable-default-ui-theme')
          );

          /** Returns `coords` shifted by `diff`. Always returns new array to illustrate rerender related problems. */
          function shift(coords: LngLat, diff: LngLat): LngLat {
              return [coords[0] + diff[0], coords[1] + diff[1]];
          }

          function App() {
              const [location, setLocation] = React.useState<{center: LngLat; zoom: number; duration?: number}>(
                  CITY_1.location
              );
              const [counter, setCounter] = React.useState(0);

              return (
                  /* Initialize the map and pass initialization parameters */
                  <MMap location={reactify.useDefault(location, [location])} ref={(x) => (map = x)}>
                      {/* Add a map scheme layer */}
                      <MMapDefaultSchemeLayer />
                      <MMapDefaultFeaturesLayer />

                      {/* MMapZoomControl sets map's `location`. Our state `location` doesn't know anything about it */}
                      <MMapControls position="right">
                          <MMapZoomControl />
                      </MMapControls>

                      <MMapControls position="top">
                          {/* Set map location with animation */}
                          <MMapControlButton
                              text={CITY_1.name}
                              onClick={() => setLocation({...CITY_1.location, duration: 1000})}
                          />
                          {/* Set map location. Create a copy of object to trigger `update` */}
                          <MMapControlButton text={CITY_2.name} onClick={() => setLocation({...CITY_2.location})} />
                          {/* Trigger rerender */}
                          <MMapControlButton text={`Rerender! ${counter}`} onClick={() => setCounter((x) => x + 1)} />
                      </MMapControls>

                      {/* Any rerender will update coordinates */}
                      <MMapDefaultMarker
                          size="normal"
                          coordinates={shift(location.center, [-0.05, -0.05])}
                          draggable
                          title="without useDefault"
                          color="pink"
                      />
                      {/* Only rerenders with changed `location.center` will update coordinates */}
                      <MMapDefaultMarker
                          size="normal"
                          coordinates={reactify.useDefault(shift(location.center, [0.05, 0.05]), [location.center])}
                          draggable
                          title="with useDefault"
                      />
                  </MMap>
              );
          }

          ReactDOM.render(
              <React.StrictMode>
                  <App />
              </React.StrictMode>,
              document.getElementById('app')
          );
      }
    </script>

    <!-- prettier-ignore -->
    <style> html, body, #app { width: 100%; height: 100%; margin: 0; padding: 0; font-family: Arial, Helvetica, sans-serif; } .toolbar { position: absolute; z-index: 1000; top: 0; left: 0; display: flex; align-items: center; padding: 16px; } .toolbar a { padding: 16px; }  </style>
    <link rel="stylesheet" href="./common.css" />
  </head>
  <body>
    <div id="app"></div>
  </body>
</html>

mappable.ready.then(() => {
  mappable.import.registerCdn('https://cdn.jsdelivr.net/npm/{package}', [
    '@mappable-world/mappable-default-ui-theme@0.0'
  ]);
});

import type {LngLat} from '@mappable-world/mappable-types';

export const CITY_1 = {
  name: 'Dubai',
  location: {
    center: [55.2744, 25.1972] as LngLat,
    zoom: 12
  }
};

export const CITY_2 = {
  name: 'Abu Dhabi',
  location: {
    center: [54.4366, 24.4604] as LngLat,
    zoom: 11
  }
};