docs.sheetjs.com/docz/docs/03-demos/15-chromium.md
2022-08-25 04:22:28 -04:00

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15 Chrome Extensions

:::warning

This demo was written using the Manifest V2 extension platform. Chrome Web Store will not accept new V2 extensions, but these can be sideloaded using the "Load unpacked" extension option.

:::

This library is compatible with Chrome and Chromium extensions and should just work out of the box. Specific API support is listed in the Chrome extensions API documentation.

Right-Click and download the final CRX

:::caution

New releases of Chrome / Chromium will block with CRX_REQUIRED_PROOF_MISSING.

To try the extension:

  1. Right-click and select "Save Link As ..." to save the CRX file

  2. Open chrome://extensions/ in the browser and enable Developer mode

  3. Click and drag the downloaded CRX file into the Extensions page to install.

:::

Relevant Operations

Generating Downloads

The writeFile function works in a Chrome or Chromium extension:

XLSX.writeFile(wb, "export.xlsx");

Under the hood, it uses the chrome.downloads API. "downloads" permission should be set in manifest.json.

Content Script Table Scraping

table_to_book and table_to_sheet can help build workbooks from DOM tables:

var tables = document.getElementsByTagName("table");
var wb = XLSX.utils.book_new();
for(var i = 0; i < tables.length; ++i) {
  var ws = XLSX.utils.table_to_sheet(tables[i]);
  XLSX.utils.book_append_sheet(wb, ws, "Table" + i);
}

Demo

The demo extension includes multiple features to demonstrate sample usage. Production extensions should include proper error handling.

Testing Unpacked Extension (click to show)
  1. Right-Click and download the zip

  2. Create a SheetJSChromium folder in your Downloads directory, move the zip file into the folder, and extract the zip file.

  3. Open chrome://extensions/ in the browser and enable Developer mode

  4. Click "Load Unpacked" and select the SheetJSChromium folder.

Bookmark Exporter

chrome.bookmarks API enables bookmark tree traversal. The "Export Bookmarks" button in the extension pop-up recursively walks the bookmark tree, pushes the bookmark URLs into a data array, and exports into a simple spreadsheet:

/* walk the bookmark tree */
function recurse_bookmarks(data, tree) {
  if(tree.url) data.push({Name: tree.title, Location: tree.url});
  (tree.children||[]).forEach(function(child) { recurse_bookmarks(data, child); });
}

/* get bookmark data */
chrome.bookmarks.getTree(function(res) {
  /* load into an array */
  var data = [];
  res.forEach(function(t) { recurse_bookmarks(data, t); });

  /* create worksheet */
  var ws = XLSX.utils.json_to_sheet(data, { header: ['Name', 'Location'] });

  /* create workbook and export */
  var wb = XLSX.utils.book_new();
  XLSX.utils.book_append_sheet(wb, ws, 'Bookmarks');
  XLSX.writeFile(wb, "bookmarks.xlsx");
});

Table Exporter

The content.js content script converts a table in the DOM to workbook object using the table_to_book utility function:

// event page script trigger
chrome.tabs.sendMessage(tab.id);
// content script convert
var wb = XLSX.utils.table_to_book(elt);
// event page script callback
XLSX.writeFile(wb, "export.xlsx");

Since the workbook object is a plain JS object, the object is sent back to an event page script which generates the file and attempts a download.