HomeWork/js/lesson21_HW/pagination.js

function Pagination(paginatedList, paginationContainer, paginationLimit = 5, listItemTag = "li"){
  const createMainPagination = ()=>{
    paginationContainer.innerHTML =
      `
      <nav aria-label="Page navigation example">
        <ul class="pagination justify-content-center">
          <li class="page-item disabled" id="prev-button" tabindex="-1">
            <a class="page-link" href="#${location.hash}" tabindex="-1">Previous</a>
          </li>
          <!--<li class="page-item"><a class="page-link" href="#${location.hash}">1</a></li>
          <li class="page-item"><a class="page-link" href="#${location.hash}">2</a></li>
          <li class="page-item"><a class="page-link" href="#${location.hash}">3</a></li>-->
          <li class="page-item" id="next-button">
            <a class="page-link" href="#${location.hash}">Next</a>
          </li>
        </ul>
      </nav>
      `;
  }
  createMainPagination();
  const listItems = paginatedList.querySelectorAll(listItemTag);
  const nextButton = paginationContainer.querySelectorAll("#next-button")[0];
  const prevButton = paginationContainer.querySelectorAll("#prev-button")[0];
  
  const pageCount = Math.ceil(listItems.length / paginationLimit);
  let currentPage = 1;
  
  const disableButton = (button) => {
    button.classList.add("disabled");
    button.setAttribute("disabled", true);
  };
  
  const enableButton = (button) => {
    button.classList.remove("disabled");
    button.removeAttribute("disabled");
  };
  
  const handlePageButtonsStatus = () => {
    if (currentPage === 1) {
      disableButton(prevButton);
    } else {
      enableButton(prevButton);
    }
  
    if (pageCount === currentPage) {
      disableButton(nextButton);
    } else {
      enableButton(nextButton);
    }
  };
  
  const handleActivePageNumber = () => {
    document.querySelectorAll(".page-item").forEach((button) => {
      button.classList.remove("active");
      const pageIndex = Number(button.getAttribute("page-index"));
      if (pageIndex == currentPage) {
        button.classList.add("active");
      }
    });
  };
  
  const appendPageNumber = (index) => {
    const pageNumber = document.createElement("li");
    pageNumber.classList.add("page-item");
    pageNumber.innerHTML = `<a class="page-link" href="#${location.hash}">${index}</a>`;
    pageNumber.setAttribute("page-index", index);
    pageNumber.setAttribute("aria-label", "Page " + index);
    nextButton.parentNode.insertBefore(pageNumber, nextButton);
  };
  
  const getPaginationNumbers = () => {
    for (let i = 1; i <= pageCount; i++) {
      appendPageNumber(i);
    }
  };
  
  const setCurrentPage = (pageNum) => {
    currentPage = pageNum;
    if (currentPage < 1 || currentPage > pageCount)
      return;
  
    handleActivePageNumber();
    handlePageButtonsStatus();
    
    const prevRange = (pageNum - 1) * paginationLimit;
    const currRange = pageNum * paginationLimit;
  
    listItems.forEach((item, index) => {
      item.classList.add("d-none");
      if (index >= prevRange && index < currRange) {
        item.classList.remove("d-none");
      }
    });
  };

  function init() {
    getPaginationNumbers();
    setCurrentPage(1);
  
    prevButton.addEventListener("click", () => {
      setCurrentPage(currentPage - 1);
    });
  
    nextButton.addEventListener("click", () => {
      setCurrentPage(currentPage + 1);
    });
  
    document.querySelectorAll(".page-item").forEach((button) => {
      const pageIndex = Number(button.getAttribute("page-index"));
  
      if (pageIndex) {
        button.childNodes[0].addEventListener("click", (event) => {
          event.preventDefault();
          if (!button.classList.contains('disabled'))
            setCurrentPage(pageIndex);
        });
      }
    });
  }
  init();
}