Programming Tutorials

Multiple File Upload in PHP using IFRAME

By: Tom @ nono . be in PHP Tutorials on 2012-12-05  

Handling multiple uploads can be a lot more user friendly with a little help of javascript and form posting to iFrame... To make it all a little bit more edible, you can use AJAX and divs to provide loader gifs etc...

Work with separate forms; note the target of each form = csr. It is the ID of an iFrame somewhere on the page. I call it CSR as short for Client-Server-Request.

Also note the hidden input formId that we will use in the php upload handler.

disable submitting the form using onsubmit="return false"...

Finally a button outside the form structure starting a javascript function onclick="upload(document.form_0, document.loader_0)"

<form onsubmit="return false" id="file_0" name="file_0" action="upload.php" target="csr" enctype="multipart/form-data" method="post" style="margin:px; padding:0px"> 
 <table width="100%" border="0" cellspacing="0" cellpadding="0"> 
 <tr> 
 <td>File 1:</td> 
 <td> 
 <input type="hidden" id="formId" name="formId" value="0" /> 
 <input type="hidden" id="MAX_FILE_SIZE" name="MAX_FILE_SIZE" value="1000000" /> 
 <input type="file" id="userFile" name="userFile" class="invulveld100pct" /> 
 </td> 
 <td> 
 <div id="loader_0"></div> 
 </td> 
 </tr> 
 </table> 
</form> 
<form onsubmit="return false" id="file_1" name="file_1" action="upload.php" target="csr" enctype="multipart/form-data" method="post" style="margin:px; padding:0px"> 
 <table width="100%" border="0" cellspacing="0" cellpadding="0"> 
 <tr> 
 <td>File 2:</td> 
 <td> 
 <input type="hidden" id="formId" name="formId" value="1" /> 
 <input type="hidden" id="MAX_FILE_SIZE" name="MAX_FILE_SIZE" value="1000000" /> 
 <input type="file" id="userFile" name="userFile" class="invulveld100pct" /> 
 </td> 
 <td> 
 <div id="loader_0"></div> 
 </td> 
 </tr> 
 </table> 
</form> 
<input type="button" onclick="upload(document.form_0, document.loader_0)" /> 
<iframe id="csr" name="csr" height="1" width="1" style="border:0px none"></iframe>
 
<!--//The javascript://-->

 <script type="javascript"> 
function upload(form, loader){ 
 //only do this if the form exists 
 if(form){ 
 //display a loadbar 
 loader.innerHTML = 'loading.gif'; 
 form.submit(); 
 } 
} 
</script>

The php upload handler upload.php Remember, your page will not refresh because the post is sent to your CSR iFrame.

<?php 
//there are enough examples around to handle the upload... 
//the only important difference is the error reporting and the starting of the next form upload... 
//presume $uploadOk is a boolean that is true if the upload succeeds; false if it fails... 
//note the use of "parent" in the outputted javascript... the script is outputted into the CSR iFrame... therefor it needs parent to acces dom objects and javascript of the main page. 

$currentFormId = $_POST['formId']; 
$nextFormId = $_POST['formId'] + 1; 

 echo "<script type=\"javascript\">"; 

 //change the content of your loader div to a desired image 
if($uploadOk){ 
 echo "parent.loader_{$currentFormId}.innerHTML = 'uploadOk.gif';"; 
} else { 
 echo "parent.loader_{$currentFormId}.innerHTML = 'uploadNotOk.gif';"; 
} 

 //submit the next form... the javascript function will only perform it if the form exists. 
echo "parent.upload(document.form_{$nextFormId}, document.loader_{$nextFormId});"; 

 echo "</script>"; 

 ?> 

This is just a quick draft of how to handle multiple files this way and I'm sure you would need to optimize the workflow to fit your needs, but the benefit of working this way is although your user still chooses multiple files, they are in fact posted one by one... This means your MAX_FILE_SIZE is determined for each file separately as opposed to the combined size of all files in one post.