feat(enhanceElement): utility for generating Google Maps Components

src/lib/enhanceElement.js

@@ -0,0 +1,159 @@
+/* global google */
+import _ from "lodash";
+
+export function addDefaultPrefixToPropTypes(propTypes: Object) {
+  return _.mapKeys(propTypes, (value, key) =>
+    `default${key.substr(0, 1).toUpperCase()}${key.substr(1)}`
+  );
+}
+
+function removeDefaultPrefix(defaultKey) {
+  // default = 7
+  const key = defaultKey.substr(7);
+  return `${key.substr(0, 1).toLowerCase()}${key.substr(1)}`;
+}
+
+function collectProps(propTypes: Object, props: Object, keyTransform = _.identity) {
+  return _.reduce(propTypes, (acc, value, key) => {
+    if (_.has(props, key)) {
+      const nextKey = keyTransform(key);
+      // eslint-disable-next-line no-param-reassign
+      acc[nextKey] = props[key];
+    }
+    return acc;
+  }, {});
+}
+
+export function collectUncontrolledAndControlledProps(
+  defaultUncontrolledPropTypes: Object,
+  controlledPropTypes: Object,
+  props: Object
+) {
+  return {
+    ...collectProps(defaultUncontrolledPropTypes, props, removeDefaultPrefix),
+    ...collectProps(controlledPropTypes, props),
+  };
+}
+
+function registerGoogleEventsFromReactProps(
+  instance: Object,
+  props: Object,
+  eventMap: Object
+) {
+  const registered = _.reduce(eventMap, (acc, googleEventName, onEventName) => {
+    if (_.has(props, onEventName)) {
+      acc.push(
+        google.maps.event.addListener(instance, googleEventName, props[onEventName])
+      );
+    }
+    return acc;
+  }, []);
+
+  return _.bind(_.forEach, null, registered, event =>
+    google.maps.event.removeListener(event)
+  );
+}
+
+function registerEventsFromComponent(component, getInstanceFromComponent, eventMap) {
+  const instance = getInstanceFromComponent(component);
+  // eslint-disable-next-line no-param-reassign
+  component._unregisterEvents = registerGoogleEventsFromReactProps(
+    instance,
+    component.props,
+    eventMap
+  );
+}
+
+function unregisterEventsFromComponent(component, getInstanceFromComponent) {
+  // eslint-disable-next-line no-param-reassign
+  component._unregisterEvents();
+  // eslint-disable-next-line no-param-reassign
+  component._unregisterEvents = _.noop;
+}
+
+const enhanceWithPropTypes = _.curry((
+  getInstanceFromComponent,
+  controlledPropUpdaterMap,
+  componentSpec
+) => {
+  const {
+    componentDidUpdate = _.noop,
+  } = componentSpec;
+
+  return {
+    ...componentSpec,
+
+    componentDidUpdate(prevProps, prevState) {
+      _.forEach(controlledPropUpdaterMap, (fn, key) => {
+        const nextValue = this.props[key];
+        if (nextValue !== prevProps[key]) {
+          fn(getInstanceFromComponent(this), nextValue);
+        }
+      });
+      componentDidUpdate.call(this, prevProps, prevState);
+    },
+  };
+});
+
+const enhanceWithEventMap = _.curry((
+  getInstanceFromComponent,
+  eventMap,
+  componentSpec
+) => {
+  const {
+    componentDidMount = _.noop,
+    componentDidUpdate = _.noop,
+    componentWillUnmount = _.noop,
+  } = componentSpec;
+
+  return {
+    ...componentSpec,
+
+    _unregisterEvents: _.noop,
+
+    componentDidMount() {
+      componentDidMount.call(this);
+      registerEventsFromComponent(this, getInstanceFromComponent, eventMap);
+    },
+
+    componentDidUpdate(prevProps, prevState) {
+      unregisterEventsFromComponent(this, getInstanceFromComponent);
+      componentDidUpdate.call(this, prevProps, prevState);
+      registerEventsFromComponent(this, getInstanceFromComponent, eventMap);
+    },
+
+    componentWillUnmount() {
+      unregisterEventsFromComponent(this, getInstanceFromComponent);
+      componentWillUnmount.call(this);
+    },
+  };
+});
+
+const enhanceWithPublicMethod = _.curry((
+  getInstanceFromComponent,
+  publicMethodMap,
+  componentSpec
+) => (
+  _.reduce(publicMethodMap, (acc, fn, publicMethodName) => {
+    // eslint-disable-next-line no-param-reassign
+    acc[publicMethodName] = function publicMethod(...args) {
+      return fn(getInstanceFromComponent(this), args, /* Use with caution */this);
+    };
+    return acc;
+  }, {
+    ...componentSpec,
+  })
+));
+
+export default function enhanceElement(
+  getInstanceFromComponent,
+  publicMethodMap,
+  eventMap,
+  controlledPropUpdaterMap
+) {
+  return _.flowRight(
+    enhanceWithPublicMethod(getInstanceFromComponent, publicMethodMap),
+    enhanceWithEventMap(getInstanceFromComponent, eventMap),
+    enhanceWithPropTypes(getInstanceFromComponent, controlledPropUpdaterMap),
+  );
+}