I am trying to make a webpage for uploading image file and storing the uploaded file on server. There are several features in this implementation:

  1. There is a drag & drop zone on the webpage. You can drag the file to be uploaded to this zone and drop. Also, you can click this zone and select the file to be uploaded.

  2. After selecting file, you can check the selected filename on the webpage.

  3. Finally, you can click "Upload To Server" button to perform the upload process.

  4. There is a progress bar for displaying the upload progress.

  5. On server side, the uploaded files are placed in folder /var/www/html/uploads/ and filenames are updated with $date_time prefix.

The experimental implementation

  • index.html: main page for selecting and uploading file

    <!DOCTYPE html>
            html {
                font-family: sans-serif;
            div#drop_zone {
                height: 400px;
                width: 400px;
                border: 2px dotted black;
                display: flex;
                justify-content: center;
                flex-direction: column;
                align-items: center;
                font-family: monospace;
        <h2>Upload File Page</h2>
        <!╌ https://stackoverflow.com/a/14806776/6667035 ╌>
        <input type="file" name="file_to_upload" id="file_to_upload" accept=".bmp, .jpg, .png" style="display: none;" multiples>
        <h3>Drag & Drop a File</h3>
        <div id="drop_zone">
            DROP HERE
        Selected filename: 
        <p id="file_name"></p>
        <progress id="progress_bar" value="0" max="100" style="width:400px;"></progress>
        <p id="progress_status"></p>
        <input type="button" value="Upload To Server" id="upload_file_button">
        <script type="text/javascript">
            document.getElementById('file_to_upload').addEventListener('change', (event) => {
                window.selectedFile = event.target.files[0];
                document.getElementById('file_name').innerHTML = window.selectedFile.name;
            document.getElementById('upload_file_button').addEventListener('click', (event) => {
                //  Reference: https://stackoverflow.com/a/154068/6667035
                if (document.getElementById('file_name').innerHTML === "") {
                    //  Reference: https://stackoverflow.com/a/10462885/6667035
                    var check = confirm("Please select a file!");
                    if (check == true) {
                        return true;
                    else {
                        return false;
                } else {
            const dropZone = document.getElementById('drop_zone'); //Getting our drop zone by ID
            dropZone.addEventListener("click", drop_zone_on_click); //  Regist on click event
            if (window.FileList && window.File) {
                dropZone.addEventListener('dragover', event => {
                    event.dataTransfer.dropEffect = 'copy'; //Adding a visual hint that the file is being copied to the window
                dropZone.addEventListener('drop', event => {
                    const files = event.dataTransfer.files; //Accessing the files that are being dropped to the window
                    window.selectedFile = files[0]; //Getting the file from uploaded files list (only one file in our case)
                    document.getElementById('file_name').innerHTML = window.selectedFile.name; //Assigning the name of file to our "file_name" element
            // ---- function definition ----
            async function drop_zone_on_click(){
                let files = await selectFile("image/*", true);
                window.selectedFile = files[0];
                document.getElementById('file_name').innerHTML = files[0].name;
            //  Reference: https://stackoverflow.com/a/52757538/6667035
            function selectFile (contentType, multiple){
                return new Promise(resolve => {
                    let input = document.createElement('input');
                    input.type = 'file';
                    input.multiple = multiple;
                    input.accept = contentType;
                    input.onchange = _ => {
                        let files = Array.from(input.files);
                        if (multiple)
            function uploadFile(file) {
                var formData = new FormData();
                formData.append('file_to_upload', file);
                var ajax = new XMLHttpRequest();
                ajax.upload.addEventListener("progress", progressHandler, false);
                ajax.open('POST', 'uploader.php', true);
            function progressHandler(event) {
                var percent = (event.loaded / event.total) * 100;
                document.getElementById("progress_bar").value = Math.round(percent);
                document.getElementById("progress_status").innerHTML = Math.round(percent) + "% uploaded";
  • uploader.php: performing the storing files in the back-end.

    $file_name = $_FILES["file_to_upload"]["name"];
    $uploaddir = '/var/www/html/uploads/';
    //  Reference: https://stackoverflow.com/a/8320892/6667035
    //  Reference: https://stackoverflow.com/a/18929210/6667035
    //  Reference: https://stackoverflow.com/a/27961373
    $time = date("Y-m-d_H-i-s_");
    $file_name_on_server = $uploaddir . $time . basename($file_name);
    $file_temp_location = $_FILES["file_to_upload"]["tmp_name"]; 
    if (!$file_temp_location) { 
        echo "ERROR: No file has been selected";
    if ($_FILES["file"]["error"] > 0) 
        echo "Return Code: " . $_FILES["file"]["error"] . "<br />";
    if(move_uploaded_file($file_temp_location, $file_name_on_server)){
        echo "$file_name upload is complete";
        //  Reference: https://www.php.net/manual/en/function.system.php
        $last_line = system('ls', $retval);
    } else {
        echo 'Error code' . $_FILES['file_to_upload']['error'] . '<br/>';
        echo "A server was unable to move the file";
    return NoContent();

The webpage screenshot


All suggestions are welcome.

  • 1
    \$\begingroup\$ You forgot to mention that it has a progress bar. Code looks fine to me. You could consider putting the Javascript in a separate file and make it reusable. Next up: Do something with the uploaded file. \$\endgroup\$ Feb 27, 2022 at 9:40
  • \$\begingroup\$ @KIKOSoftware Thank you for the suggestion. \$\endgroup\$
    – JimmyHu
    Mar 1, 2022 at 0:00
  • \$\begingroup\$ Does function NoContent() reference $last_line or $retval? \$\endgroup\$ Mar 1, 2022 at 5:09


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