feat(react-hooks): implemented hooks for react 16.8+ to use with tao.js

affects: @tao.js/react

useTaoXxxHandler and useTaoDataContext provide conveniences
for functional components

ISSUES CLOSED: #26

packages/react-tao/src/helpers.js

@@ -8,8 +8,12 @@ export function normalizeAC({ t, term, a, action, o, orient }) {
   };
 }
 
-export const cleanInput = ({ term, action, orient }) => {
+export function cleanInput({ term, action, orient }) {
   const incoming = { term, action, orient };
   Object.keys(incoming).forEach(k => incoming[k] == null && delete incoming[k]);
   return incoming;
-};
+}
+
+export function normalizeClean({ t, term, a, action, o, orient }) {
+  return cleanInput(normalizeAC({ t, term, a, action, o, orient }));
+}

packages/react-tao/src/hooks.js

@@ -0,0 +1,81 @@
+import { useContext, useEffect, useLayoutEffect } from 'react';
+import { Context } from './Provider';
+import { normalizeClean } from './helpers';
+
+function getPermutations({ t, term, a, action, o, orient }) {
+  const trigram = normalizeClean({ t, term, a, action, o, orient });
+  return cartesian(trigram);
+}
+
+function handlerForPermutations(taoHandle, permutations, handler) {
+  if (permutations.length) {
+    permutations.forEach(({ term, action, orient }) =>
+      taoHandle({ term, action, orient }, handler)
+    );
+  }
+}
+
+function useTaoEffect(
+  handlerType,
+  { t, term, a, action, o, orient },
+  handler,
+  dependencies
+) {
+  const [addingHandler, removingHandler] = [
+    `add${handlerType}Handler`,
+    `remove${handlerType}Handler`
+  ];
+  const { TAO } = useContext(Context);
+  const permutations = getPermutations({ t, term, a, action, o, orient });
+  useEffect(() => {
+    handlerForPermutations(TAO[addingHandler], permutations, handler);
+    return () => {
+      handlerForPermutations(TAO[removingHandler], permutations, handler);
+    };
+  }, dependencies);
+}
+
+export function useTaoInlineHandler(
+  { t, term, a, action, o, orient },
+  handler,
+  dependencies
+) {
+  useTaoEffect(
+    'Inline',
+    { t, term, a, action, o, orient },
+    handler,
+    dependencies
+  );
+}
+
+export function useTaoAsyncHandler(
+  { t, term, a, action, o, orient },
+  handler,
+  dependencies
+) {
+  useTaoEffect(
+    'Async',
+    { t, term, a, action, o, orient },
+    handler,
+    dependencies
+  );
+}
+
+export function useTaoInterceptHandler(
+  { t, term, a, action, o, orient },
+  handler,
+  dependencies
+) {
+  useTaoEffect(
+    'Intercept',
+    { t, term, a, action, o, orient },
+    handler,
+    dependencies
+  );
+}
+
+export function useTaoDataContext(name) {
+  const { getDataContext } = useContext(Context);
+  const dataContext = getDataContext(name);
+  return useContext(dataContext);
+}

packages/react-tao/src/index.js

@@ -5,3 +5,4 @@ export { default as RenderHandler } from './RenderHandler';
 export { default as SwitchHandler } from './SwitchHandler';
 export { default as createContextHandler } from './createContextHandler';
 export { default as withContext } from './withContext';
+export * from './hooks';