Browser script to convert HTML tables to CSV

htmlTableToCsv.js

(function () {
	/**
	 * @instructions
	 * 1. RENAME FILE_NAME TO CHANGE THE NAME OF THE EXPORT FILE
	 * const FILE_NAME = 'whatever_you_want.csv'
	 *
	 * 2. Open the browser console on the page you want to copy (Chrome)
	 * command + option + j
	 *
	 * 3. Copy and paste the entirety of this Gist to download the table
	 *
	 * Reference:
	 * codexworld.com/export-html-table-data-to-csv-using-javascript/
	 * https://stackoverflow.com/questions/7275650/javascript-replace-command-replace-page-text/7275856#7275856
	 */
	 
	const FILE_NAME = 'export.csv';

	// Removes commas from the document that mess up the comma seperated CSV
	function removeCommasFromDocument() {
		// create a TreeWalker of all text nodes
		const allTextNodes = document.createTreeWalker(
			document.body,
			NodeFilter.SHOW_TEXT,
		);
		// some temp references for performance
		let tmptxt;
		let tmpnode;
		// compile the RE and cache the replace string, for performance
		const commaRE = /,/g;
		const replaceValue = '';

		// iterate through all text nodes
		while (allTextNodes.nextNode()) {
			tmpnode = allTextNodes.currentNode;
			tmptxt = tmpnode.nodeValue;
			tmpnode.nodeValue = tmptxt.replace(commaRE, replaceValue);
		}
	}

	// Creates html download link with the csv data
	function downloadCSV(csv, filename) {
		let csvFile;
		let downloadLink;

		// CSV file
		csvFile = new Blob([csv], { type: 'text/csv' });

		// Download link
		downloadLink = document.createElement('a');

		// File name
		downloadLink.download = filename;

		// Create a link to the file
		downloadLink.href = window.URL.createObjectURL(csvFile);

		// Hide download link
		downloadLink.style.display = 'none';

		// Add the link to DOM
		document.body.appendChild(downloadLink);

		// Click download link
		downloadLink.click();
	}

	// Gets all the data from the html table and exports it
	function exportTableToCSV(filename) {
		const csv = [];
		const rows = document.querySelectorAll('table tr');

		for (let i = 0; i < rows.length; i++) {
			const row = [];
			const cols = rows[i].querySelectorAll('td, th');

			for (let j = 0; j < cols.length; j++)
				row.push(cols[j].innerText);

			csv.push(row.join(','));
		}

		// Download CSV file
		downloadCSV(csv.join('\n'), filename);
	}

	// Put it all together
	removeCommasFromDocument();
	exportTableToCSV(FILE_NAME);
})();