Prevent Class from filling with empty values - php

Question

I wrote a upload script on my site where users can upload a predefined number of items (12 in my case). A user can edit his project (of course...).
So I also wrote an update-script. Project are read from the database and a user can reupload or delete certain files. But what I have write know is, when a users doesn't upload a new file, the original file is overwritten by an empty value (makes sense, since the <input> is empty.
But I want to prevent that. How do I do this?
Form:
$activities = Project::getProjectById($_DB, $projectnumber);
if(!empty($activities)) {
foreach($activities as $k => $v) {
echo "<input type='text' value='".$v['name']."' name = 'newproject_name' />";
$i = 1;
while ($i <= 12) {
if(!empty($v["photo$i"])) {
echo "<img src='../files/".$v["photo$i"]."' width='200' height='200' />";
echo "<input type='file' name='images[]' />";
}
$i++;
}
}
echo "<input type=submit value='Update' name='submitted'>";
echo "</form>";
}
PHP:
$project = new Project();
$project->name = $_POST['newproject_name'];
$project->photo1 = $_FILES['images']['name'][0];
$project->photo2 = $_FILES['images']['name'][1];
$project->photo3 = $_FILES['images']['name'][2];
$project->photo4 = $_FILES['images']['name'][3];
$project->photo5 = $_FILES['images']['name'][4];
$project->photo6 = $_FILES['images']['name'][5];
$project->photo7 = $_FILES['images']['name'][6];
$project->photo8 = $_FILES['images']['name'][7];
$project->photo9 = $_FILES['images']['name'][8];
$project->photo10 = $_FILES['images']['name'][9];
$project->photo11 = $_FILES['images']['name'][10];
$project->photo12 = $_FILES['images']['name'][11];
if($project->updateProject($_DB, $projectnummer)) {
$feedback = "<div class='feedback good'>ok!!</div>";
} else {
$feedback = "<div class='feedback bad'>NOT ok!</div>";
}
You don't have to worry about the getProjectById and updateProject-function, they work just fine. But as you can see, the script will upload all the empty values and overwrite them in the database...
I would like to prevent that! Any advice?
EDIT:
if (!empty($_FILES['images']['name'][0])) {
$project->photo1 = $_FILES['images']['name'][0];
}
if (!empty($_FILES['images']['name'][1])) {
$project->photo2 = $_FILES['images']['name'][1];
}
if (!empty($_FILES['images']['name'][2])) {
$project->photo3 = $_FILES['images']['name'][2];
}
if (!empty($_FILES['images']['name'][3])) {
$project->photo4 = $_FILES['images']['name'][3];
}
if (!empty($_FILES['images']['name'][4])) {
$project->photo5 = $_FILES['images']['name'][4];
}
if (!empty($_FILES['images']['name'][5])) {
$project->photo6 = $_FILES['images']['name'][5];
}
if (!empty($_FILES['images']['name'][6])) {
$project->photo7 = $_FILES['images']['name'][6];
}
if (!empty($_FILES['images']['name'][7])) {
$project->photo8 = $_FILES['images']['name'][7];
}
if (!empty($_FILES['images']['name'][8])) {
$project->photo9 = $_FILES['images']['name'][8];
}
if (!empty($_FILES['images']['name'][9])) {
$project->photo10 = $_FILES['images']['name'][9];
}
if (!empty($_FILES['images']['name'][10])) {
$project->photo11 = $_FILES['images']['name'][10];
}
if (!empty($_FILES['images']['name'][11])) {
$project->photo12 = $_FILES['images']['name'][11];
}

Answer 1

$project->photo1 = $_FILES['images']['name'][0];
$project->photo2 = $_FILES['images']['name'][1];
$project->photo3 = $_FILES['images']['name'][2];
$project->photo4 = $_FILES['images']['name'][3];
$project->photo5 = $_FILES['images']['name'][4];
$project->photo6 = $_FILES['images']['name'][5];
$project->photo7 = $_FILES['images']['name'][6];
$project->photo8 = $_FILES['images']['name'][7];
$project->photo9 = $_FILES['images']['name'][8];
$project->photo10 = $_FILES['images']['name'][9];
$project->photo11 = $_FILES['images']['name'][10];
$project->photo12 = $_FILES['images']['name'][11];
can be rewriten as
for ($i = 0; $i <=11; $i++) {
$photo = 'photo' . ($i + 1);
$project->$photo = $_FILES['images']['name'][$i];
}
And you can resume all your edit with:
for ($i = 0; $i <=11; $i++) {
$photo = 'photo' . ($i + 1);
if ( ! empty($_FILES['images']['name'][$i])) {
$project->$photo = $_FILES['images']['name'][$1];
}
}

Answer 2

Maybe You should use is_uploaded_file() function (LINK)?
EDIT:
for($i = 0; $i <= 11; $i++) {
if(!is_uploaded_file($_FILES['images']['name'][$i]))
$project->photo[$i] = $_FILES['images']['name'][$i];
}