const workOnData = data => {
  data.forEach(concert => { // Hver object er  betur þekktur sem concert
    totalGroupName.push(concert.userGroupName); // Bætt er við aðila í umsjón-listann

    const cardParent = document.createElement('div');
    const card = document.createElement('div');
    const cardImage = document.createElement('div');
    const figure = document.createElement('div');
    const img = document.createElement('img');
    const cardContent = document.createElement('div');
    const content = document.createElement('div');
    const title = document.createElement('p');
    const subtitle = document.createElement('p');
    const groupName = document.createElement('p');
    const location = document.createElement('p');
    const cardFooter = document.createElement('footer');
    const cardFooterItem = document.createElement('p');
    const time = document.createElement('time');

    cardParent.dataset.title = concert.eventDateName;
    cardParent.dataset.groupName = concert.userGroupName;
    cardParent.dataset.name = concert.name;
    cardParent.dataset.location = concert.eventHallName;
    cardParent.dataset.dateTime = concert.dateOfShow;
    cardParent.dataset.titleHidden = false;
    cardParent.dataset.locationHidden = false;
    cardParent.dataset.dateHidden = false;
    cardParent.dataset.groupNameHidden = false;

    cardParent.classList.add('column', 'is-one-quarter');
    card.classList.add('card');
    cardImage.classList.add('card-image');
    figure.classList.add('image', 'is-3by3');
    img.src = concert.imageSource;
    cardContent.classList.add('card-content');
    content.classList.add('content');
    title.classList.add('title', 'is-5');
    subtitle.classList.add('subtitle', 'is-5');
    groupName.classList.add('subtitle', 'is-6');
    location.classList.add('subtitle', 'is-6');
    cardFooter.classList.add('card-footer');
    cardFooterItem.classList.add('card-footer-item');

    title.textContent = concert.eventDateName;
    subtitle.textContent = concert.userGroupName;
    location.innerHTML = `<i> ${concert.eventHallName}, ${concert.name}</i>`;

    moment.locale('is'); // Stilla á Ísland
    time.textContent = moment(concert.dateOfShow).format('lll');

    // Byggt upp card
    cardParent.appendChild(card)

    card.appendChild(cardImage);
    card.appendChild(cardContent);
    card.appendChild(cardFooter);

    cardImage.appendChild(figure);
    figure.appendChild(img);

    cardContent.appendChild(content);
    content.appendChild(title);
    content.appendChild(subtitle);
    content.appendChild(groupName);
    content.appendChild(location);

    cardFooter.appendChild(cardFooterItem);
    cardFooterItem.appendChild(time);

    currGallery.push(cardParent); // Concert card er bætt við í gallery
  });