Cleanups and better navigation between docs

plugins/techdocs/src/reader/components/Reader.tsx

@@ -17,10 +17,14 @@
 import React from 'react';
 import { useShadowDom } from '..';
 import { useAsync } from 'react-use';
-import transformer, { addBaseUrl, rewriteDocLinks } from '../transformers';
+import transformer, {
+  addBaseUrl,
+  rewriteDocLinks,
+  addEventListener,
+} from '../transformers';
 import { docStorageURL } from '../../config';
 import { Link } from '@backstage/core';
-import { useLocation, useParams } from 'react-router-dom';
+import { useLocation, useParams, useNavigate } from 'react-router-dom';
 import URLParser from '../urlParser';
 
 const useFetch = (url: string) => {
@@ -33,10 +37,6 @@ const useFetch = (url: string) => {
   return state;
 };
 
-const normalizeUrl = (path: string) => {
-  return path.replace(/\/\/index.html$/, '/index.html');
-};
-
 const useEnforcedTrailingSlash = (): void => {
   React.useEffect(() => {
     const actualUrl = window.location.href;
@@ -52,11 +52,12 @@ export const Reader = () => {
   const location = useLocation();
   const { componentId, '*': path } = useParams();
   const shadowDomRef = useShadowDom();
-  const state = useFetch(
-    normalizeUrl(
-      `${docStorageURL}${location.pathname.replace('/docs', '')}/index.html`,
-    ),
-  );
+  const navigate = useNavigate();
+  const normalizedUrl = new URLParser(
+    `${docStorageURL}${location.pathname.replace('/docs', '')}`,
+    '.',
+  ).parse();
+  const state = useFetch(`${normalizedUrl}index.html`);
 
   useEnforcedTrailingSlash();
 
@@ -75,10 +76,16 @@ export const Reader = () => {
       ]);
 
       divElement.shadowRoot.innerHTML = '';
-      if (transformedElement)
+      if (transformedElement) {
         divElement.shadowRoot.appendChild(transformedElement);
+        transformer(divElement.shadowRoot.children[0], [
+          addEventListener({
+            onClick: navigate,
+          }),
+        ]);
+      }
     }
-  }, [shadowDomRef, state, componentId, path]);
+  }, [shadowDomRef, state, componentId, path, navigate]);
 
   return (
     <>

plugins/techdocs/src/reader/transformers/addBaseUrl.ts

@@ -15,6 +15,7 @@
  */
 
 import URLParser from '../urlParser';
+import type { Transformer } from './index';
 
 type AddBaseUrlOptions = {
   docStorageURL: string;
@@ -26,10 +27,10 @@ export const addBaseUrl = ({
   docStorageURL,
   componentId,
   path,
-}: AddBaseUrlOptions) => {
-  return (dom: Document): Document => {
+}: AddBaseUrlOptions): Transformer => {
+  return dom => {
     const updateDom = <T extends Element>(
-      list: Array<T>,
+      list: HTMLCollectionOf<T> | NodeListOf<T>,
       attributeName: string,
     ): void => {
       Array.from(list)
@@ -43,12 +44,9 @@ export const addBaseUrl = ({
         });
     };
 
-    updateDom<HTMLImageElement>(Array.from(dom.images), 'src');
-    updateDom<HTMLScriptElement>(Array.from(dom.scripts), 'src');
-    updateDom<HTMLLinkElement>(
-      Array.from(dom.querySelectorAll('link')),
-      'href',
-    );
+    updateDom<HTMLImageElement>(dom.querySelectorAll('img'), 'src');
+    updateDom<HTMLScriptElement>(dom.querySelectorAll('script'), 'src');
+    updateDom<HTMLLinkElement>(dom.querySelectorAll('link'), 'href');
 
     return dom;
   };

plugins/techdocs/src/reader/transformers/addEventListener.ts

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type { Transformer } from './index';
+
+type AddEventListenerOptions = {
+  onClick: (newUrl: string) => void;
+};
+
+export const addEventListener = ({
+  onClick,
+}: AddEventListenerOptions): Transformer => {
+  return dom => {
+    Array.from(dom.getElementsByTagName('a')).forEach(elem => {
+      elem.addEventListener('click', (e: MouseEvent) => {
+        e.preventDefault();
+        const target = e.target as HTMLAnchorElement;
+        if (target?.getAttribute('href')) {
+          onClick(
+            target.getAttribute('href')!.replace(window.location.origin, ''),
+          );
+        }
+      });
+    });
+
+    return dom;
+  };
+};

plugins/techdocs/src/reader/transformers/index.ts

@@ -16,16 +16,48 @@
 
 export * from './addBaseUrl';
 export * from './rewriteDocLinks';
+export * from './addEventListener';
 
-type Transformer = (dom: Document) => Document;
+export type Transformer = (dom: Element) => Element;
 
-export default (
-  html: string,
+function transform(
+  html: string | Element,
   transformers: Transformer[],
-): HTMLElement | undefined => {
-  const dom = new DOMParser().parseFromString(html, 'text/html');
+): Element {
+  let dom: Element;
+
+  if (typeof html === 'string') {
+    dom = new DOMParser().parseFromString(html, 'text/html').documentElement;
+  } else if (html instanceof Element) {
+    dom = html;
+  } else {
+    throw new Error('dom is not a recognized type');
+  }
 
   transformers.forEach(transformer => transformer(dom));
 
-  return dom.body.parentElement ?? undefined;
-};
+  return dom;
+}
+
+// function transform(
+//   html: string,
+//   transformers: Transformer[],
+// ): HTMLElement {
+//   const dom = new DOMParser().parseFromString(html, 'text/html');
+
+//   transformers.forEach(transformer => transformer(dom));
+
+//   return dom.documentElement;
+// };
+
+// function transform(
+//   html: HTMLElement,
+//   transformers: Transformer[],
+// ): HTMLElement {
+
+//   transformers.forEach(transformer => transformer(element));
+
+//   return html;
+// };
+
+export default transform;

plugins/techdocs/src/reader/transformers/rewriteDocLinks.ts

@@ -15,11 +15,12 @@
  */
 
 import URLParser from '../urlParser';
+import type { Transformer } from './index';
 
 type AddBaseUrlOptions = {};
 
-export const rewriteDocLinks = ({}: AddBaseUrlOptions) => {
-  return (dom: Document): Document => {
+export const rewriteDocLinks = ({}: AddBaseUrlOptions): Transformer => {
+  return dom => {
     const updateDom = <T extends Element>(
       list: Array<T>,
       attributeName: string,