contentScript.js

chrome.runtime.onMessage.addListener(function (request) {
  const currentUrl = window.location.href;

  if(currentUrl.indexOf("https://trello.com/b/") >= 0) {
    const lists = document.querySelectorAll('.js-list');
    lists.forEach((list) => {
      const listContent = list.querySelector('.js-list-content');
      const listHeader = list.querySelector('h2');
  
      const activeColumnsArray = request.activeColumns.split(",").map(column => column.trim().toUpperCase());
      const shouldShow = request.allColumns || activeColumnsArray.includes(listHeader.textContent.trim().toUpperCase());
  
      if(shouldShow) {
        listContent.removeAttribute('style');
        list.removeAttribute('style');
      } else {
        listContent.style.display = "none";
        list.style.backgroundColor = '#dddddd';
        list.style.borderRadius = '5px';
        list.style.width = '10px';
      }
    });
  } else {
    console.warn("Trello Views: You can only hide/show columns when viewing a board.")
  }

});