HTML File Upload - why use IFrame

Question

I have been trying to get file uploads working in IE8. To only solution I have seen is posting to an IFrame. Why is this done? Is it not possible to have a simple form e.g.

<form action="test.php" method="post" enctype="multipart/form-data">
    Select image to upload:
    <input type="file" name="fileToUpload" id="fileToUpload">
    <input type="submit" value="Upload Image" name="submit">
</form>

Which submits directly to PHP

if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}

Why would an IFrame be needed?

Thanks

Answer 1

You don't need an iframe to upload a file.

You need an iframe to upload a file without leaving the current page (i.e. for Ajax). Modern browsers support FormData which allows you to upload files with XMLHttpRequest.