Chrome Extension to display XML files built with Vue

1. Supports both CSS and XPath selectors.

2. Supports text search and Regular Expression search.

3. Both querySelectorAll and jQuery flavors of CSS selectors are available.

4. RegEx is the only CASE-INSENSITIVE one.

5. Highly optimized for large XML files ( > 1MB ).

6. Stand-alone version - extremely fast because of avoiding Chrome's slow loading process.

7. Global x variable (window.x) is available in DevTools which includes:

   • doc - raw XML document object
   • root - root XML element object
   • cur - current selected node
   • $ - jQuery bound on root element
   • history - search results
   • $q - helper for jQuery search
   • cs - helper for CSS search
   • re - helper for RegEx search
   • tx - helper for Text search
   • xp - helper for XPath search

   Above helpers are (expression, baseElement = root) => [] and searching on baseElement which is x.root by default.

• Online Demo - Remote links are very UNLIKELY working due to same-origin policy. Local files should be fine.
• Github Repo
• Report Bug
• Chrome Extension

• Add some themes
• Able to customize CSS
• More optimization

1. Vue
2. Vuex
3. lodash/debounce
4. jQuery
5. document.querySelectorAll
6. document.evaluate for XPath
7. bestzip for packaging

1. yarn dev or npm run dev
2. Open http://localhost:8080/ to start debugging.
3. Folder tests/ will be served at the same time with CORS, so http://localhost:8080/xml/default.xml is available.

1. yarn watch or npm run watch
2. Drag and drop dist folder into Chrome's Extensions page

yarn website or npm run website

Target folder is public

You can also pass PROXY env variable to enable proxy. For example,

PROXY="https://my.proxy/get?url=" yarn website

When fetching https://foo.bar/baz.xml, it will get https://my.proxy/get?url=https%3A%2F%2Ffoo.bar%2Fbaz.xml instead. You can implement your own proxy with CORS.

There is an example for webtask:

const zlib = require('zlib');
const fetch = require('node-fetch'); // 3rd-party

module.exports = async (context, req, res) => {
  const { url } = context.query;
  if (!url) {
    res.writeHead(400, { 'Content-Type': 'text/plain'});
    res.end('Required query string `url`');
    return;
  }

  try {
    const response = await fetch(url);
    const { headers } = response;
    Array.from(headers.keys()).forEach((key) => {
      if (key === 'content-type') {
        res.setHeader('Content-Type', headers.get(key));
      }
    });

    res.writeHead(response.status, {
      'Access-Control-Allow-Origin': '*', // IMPORTANT: enables CORS. You can restrict it to your own domain names.
      'Content-Encoding': 'deflate',
      'Cache-Control': 'max-age=3600',
    });

    zlib.deflate(await response.buffer(), (err, buff) => {
      if (err) throw err;
      res.end(buff);
    });
  } catch (err) {
    res.writeHead(500, { 'Content-Type': 'text/plain' });
    res.end(err.message);
  }
};

• yarn watch or npm run watch to build dev in dist folder
• yarn build or npm run build to build prod version
• yarn deploy or npm run deploy will build and get deploy/xml-plus.zip ready for Chrome store

1. Chrome - the browser itself
2. ** * *** **** - Another Extension available on Chrome Store and open-sourced on Github. Will use X to represent it.
3. XML Plus

1. Serve XML files on localhost
2. Open Chrome Developer Tools
3. Turn-on/off Extension to test
4. Kill the tab in Chrome Task Manager to avoid memory operation
5. Empty Cache and Hard Reload XML file via local network
6. Repeat step 4 to 5 and skip the first read.

Since Extension X needs more time to render the page, I put some extra code to calculate real time. The code is something like:

```js
document.addEventListener('readystatechange', function() {
  console.time('ready');
  // ... main code
});

// Inside another function
function xxx() {
  sendMessage(..., function () {
    // ...
    sendMessage(..., function () {
      // ... it will generate DOM here
      setTimeout(() => {
        console.timeEnd('ready');
      }, 0);
    });
  });
}
```

1. Round 1: 2MiB XML file (Total 41248 nodes; Max Depth: 5)

   • Chrome: 14.55s, 14.34s, 15.19s
   • X: 3.54s + 1141ms, 3.46s + 738ms, 2.94s + 898ms
   • XML Plus: 4.12s, 3.89s. 4.18s

2. Round 2: 5.2MiB XML file (Total 113126 nodes; Max Depth: 4)

   • Chrome: 34.10s, 34.82s, 33.9s (7.7s~8.0s DOMContentLoaded)
   • X: 8.50s + 3968ms, 8.74s + 3976ms, 8.44s + 3965ms (7.7s~8.0s DOMContentLoaded)
   • XML Plus: 7.32s, 7.30s, 7.50s (4.8s~5.0s DOMContentLoaded)

3. Round 3: 14.4MiB XML file (Total 307067 nodes; Max Depth: 4)

   • Chrome: 3.2min (~42s DOMContentLoaded)
   • X: 43.72s + 17449ms (~42s DOMContentLoaded)
   • XML Plus: 22.32s, 24.01s, 22.04s (13.6s~15.8s DOMContentLoaded)

• Some Conclusions:
  1. DOMContentLoaded is not avoidable.
  2. text/xml and application/xml take much longer time than text/plain which I used. If you know a better way to make Chrome avoid rendering while processing responses, please let me know!
  3. Chrome will take 1.1min+ If you don't End Process in Task Manager. It will take much longer if the tab used too much memory.
  4. In Round 2 you can see the styles of X will be applied after ready, while in Round 3 it took 7s+ to apply styles.

Windows 10 1803 x64
Intel i7-6700K
32G RAM
Chrome v71.0.3578.98 x64