forms - HTML multiple file upload from different folders

Question

I have a form with an upload field that allows users to select multiple files. However, I need to be able to allow the user to select file 1 from folder 1, then go and select file 2 from folder 2, and so on.

Currently, when the user selects file 1 from folder 1 then hits "Open", the selection window closes (leaving the user on my form). Then if the user goes and select file 2 from folder 2 and hits the "Open" button, file 1 is removed, leaving only file 2.

Basically, the user is unable to select multiple files unless they're all in the same location. Is there a way to make file 1 stay selected after file 2 is chosen?

Answer 1

How about this?

The solution uses HTML, jQuery/Javascript, and PHP (for server-side handling of this data). The idea is: 1.) HTML Form: Includes one "browse" button that allows the user to select multiple files (within one directory). 2.) jQuery: The option to create a new button in the form that allows users to select multiple files (within a different directory -- or even the same one actually!), with the ability to create new buttons "infinitely". 3.) PHP: As a bonus, I put some thought into packaging the data nicely for server-side handling.

Here is what the HTML form could look like (I used a found-icon for the clickable object, but you can easily replace it with a graphic of your choosing).

<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>" enctype='multipart/form-data'>
    Select files: <br/>
    <input type='file' name='files0[]' id="files0" multiple><br/><br/><br/>
    <span style="font-size: 10pt;">Click "+" for more files
    <i id="more_files" class="general foundicon-plus" style="color: blue;cursor: pointer;"></i></span>
    <br/><br/><br/>
    <input type="submit" name="submit" value="Submit">
</form>

Here is the jQuery/Javascript to create a new "browse" button once the event is triggered (this even places it after the LAST "browse" button!):

<script type="text/javascript">
//jQuery
$(document).ready(function() {
    $(document).on('click','#more_files', function() {
        var numOfInputs = 1;
        while($('#files'+numOfInputs).length) { numOfInputs++; }//once this loop breaks, numOfInputs is greater than the # of browse buttons

        $("<input type='file' multiple/>")
            .attr("id", "files"+numOfInputs)
            .attr("name", "files"+numOfInputs+"[]")
            .insertAfter("#files"+(numOfInputs-1));

        $("<br/>").insertBefore("#files"+numOfInputs);
    });
});
</script>
<script>
    //vanilla javascript version
    var location = document.getElementById("fileBrowsers");
    var br = document.createElement("BR");
    location.appendChild(br);
    var input = document.createElement("input");
    input.type = "file";
    input.name = "files"+numOfInputs+"[]";
            input.id = "files"+numOfInputs;
            input.multiple = true;

            location.appendChild(input);
</script>

Finally, and possibly most important, how to wrap up the data on the server in a familiar format:

<?php
if(isset($_POST['submit']) && !empty($_FILES)) {
    $files = array();
    $files = $_FILES['files0'];
    //var_dump($files);//this array will match the structure of $_FILES['browser']
    //Iterate through each browser button
    $browserIterator = 1;
    while(isset($_FILES['files'.$browserIterator])) {
        //Files have same attribute structure, so grab each attribute and append data for each attribute from each file
        foreach($_FILES['files'.$browserIterator] as $attr => $values) {//get each attribute
            foreach($_FILES['files'.$browserIterator][$attr] as $fileValue) {//get each value from attribute
                $files[$attr][] = $fileValue;//append value
            }
        }
        $browserIterator++;
    }
    //Use $files like you would use $_FILES['browser'] -- It is as though all files came from one browser button!
    $fileIterator = 0;
    while($fileIterator < count($files['name'])) {
        echo $files['name'][$fileIterator]."<br/>";
        $fileIterator++;
    }
}
?>

Update Note: jQuery script and vanilla Javascript accomplish the same goal. I ran into an issue that required the vanilla version. You only need one of them.