functions.php

<?php
//koneksi ke database
$conn= mysqli_connect("localhost", "root", "", "buku");

function query ($query) {
  global $conn;
  $result= mysqli_query($conn, $query);
  $rows= [];
  while ($row = mysqli_fetch_assoc($result)) {
    $rows[] = $row;
  }
  return $rows;
}


function tambah($data) {
  global $conn;
  $judul= htmlspecialchars($data["judul"]);
  $penulis= htmlspecialchars($data["penulis"]);
  $kategori= htmlspecialchars($data["kategori"]);
  $deskripsi= htmlspecialchars($data["deskripsi"]);
  $detail= htmlspecialchars($data["detail"]);

//upload gambar

$gambar = upload();
if (!$gambar) {
  return false;
}
$status= htmlspecialchars($data["status"]);

  $query= "INSERT INTO tabel
          VALUES
          ('', '$judul', '$penulis', '$kategori', '$deskripsi', '$detail', '$gambar', '$status')
          ";
  mysqli_query($conn, $query);

  return mysqli_affected_rows($conn);
}


function upload() {
  $namaFile = $_FILES['gambar'] ['name'];
  $ukuranFile = $_FILES['gambar'] ['size'];
  $error = $_FILES['gambar'] ['error'];
  $tmpName = $_FILES['gambar'] ['tmp_name'];

  //cek apakah tidak ada gambar yang diupload
  if ($error === 4) {
    echo "<script> alert('upload gambar terlebih dahulu!')
          </script>";
          return false;
  }
  ////cek apak yang diupload gambar atau bukan
  $ekstensiGambarValid = ["jpg", "jpeg", "png"];
  $ekstensiGambar = explode('.', $namaFile);
  $ekstensiGambar = strtolower(end($ekstensiGambar));
  if (!in_array($ekstensiGambar, $ekstensiGambarValid)) {
    echo "<script> alert('yang anda upload bukan gambar!')</script>";
  }
  //cek jika yang diupload terlalu besar ukurannya
  if( $ukuranFile > 100000000) {
    echo "<script> alert('yang anda upload terlalu besar ukurannya!')</script>";
  }
  //lolos pengecekan, gambar siap diupload
  //generate nama gambar baru
  $namaFileBaru = uniqid();
  $namaFileBaru .= '.';
  $namaFileBaru .= $ekstensiGambar;

  move_uploaded_file($tmpName, '../img/' . $namaFileBaru);
  return $namaFileBaru;
}

function hapus($id) {
  global $conn;
  mysqli_query($conn, "DELETE FROM tabel WHERE id = $id");

  return mysqli_affected_rows($conn);
}

function ubah($data) {
  global $conn;
  $id = $data["id"];
  $judul= htmlspecialchars($data["judul"]);
  $penulis= htmlspecialchars($data["penulis"]);
  $kategori= htmlspecialchars($data["kategori"]);
  $deskripsi= htmlspecialchars($data["deskripsi"]);
  $detail= htmlspecialchars($data["detail"]);
  $gambarLama= htmlspecialchars($data["gambarLama"]);
  $status= htmlspecialchars($data["status"]);
  //cek apakah user pilih gambar baru atu tidak
  if ( $_FILES['gambar'] ['error'] === 4) {
    $gambar = $gambarLama;
  } else {
    $gambar = upload;
  }



  $query= "UPDATE tabel SET
          judul = '$judul',
          penulis = '$penulis',
          kategori = '$kategori',
          deskripsi = '$deskripsi',
          detail = '$detail',
          gambar = '$gambar',
          status = '$status'
          WHERE id = '$id'
          ";
  mysqli_query($conn, $query);

  return mysqli_affected_rows($conn);
}

function cari($keyword) {
  $query = "SELECT * FROM tabel WHERE
            judul LIKE '%$keyword%' OR
            penulis LIKE '%$keyword%' ORd
            kategori LIKE '%$keyword%' OR
            deskripsi LIKE '%$keyword%' OR
            detail LIKE '%$keyword%'

            ";
            return query($query);
}

function registrasi($data) {
  global $conn;
  $nama= $data["nama"];
  $kelas = $data["kelas"];
  $username = strtolower(stripslashes($data["username"]));
  $password= mysqli_real_escape_string($conn, $data["password"]);
  $password2= mysqli_real_escape_string($conn, $data["password2"]);

  //cek username sudah ada atau belum
  $result= mysqli_query($conn, "SELECT username FROM user WHERE
  username = '$username'");
  //
  if ( mysqli_fetch_assoc($result)) {
    echo "<script> alert('username sudah ada yang punya!')</script>";
    return false;
  }
  //cek konfirmsi password2
  if ($password !== $password2) {
    echo "<script> alert('ups! konfirmasi password tidak sesuai >_<') </script>)";
    return false;
  }
    //enksripsi password
  $password = password_hash($password, PASSWORD_DEFAULT);


  //tambahkan user dulu ke database
  mysqli_query($conn, "INSERT INTO user VALUES('', '$nama', '$kelas', '$username', '$password')");
  return mysqli_affected_rows($conn);
}

 ?>