How to remove a property from a File-API object in JavaScript?
<p>I'm using the JavaScript "file" api to read information about images that will be uploaded, in order to generate a preview thumbnail before the actual upload occurs, based on a demo found here (<a href="http://www.html5rocks.com/en/tutorials/file/dndfiles/" rel="nofollow">JavaScript file api</a>).</p>

<p>Using an file input with a "multiple" attribute, one or more files can be selected at the same time, like so: <code>&lt;input type="file" id="imageFiles" name="userfile[]" multiple /&gt;</code>   </p>

<p>Once the image(s) have been selected by the user, I inspect the element with firebug and I can see in the DOM that the "files" object contains information about each image selected.</p>

<p>The "file" object will contain as many properties as files were selected and each property has information about each image. I could only describe the "file" object as an associative array in the sense that each property is an object in itself.   </p>

<p>What I want to do is be able to remove from the "file" object a given proprety, thus removing one of the images that will be uploaded, without having to select the images again.   </p>

<p>So far this is what I've tried and it does not work:   </p>

<pre><code>var getAllFiles = document.getElementById('imageFiles');
var allImages = getAllFiles.files; // returns an object with X properties
delete allImages[X]; // "X" is whatever property key I'm passing in
</code></pre>

<p>I've tried the "splice()" method but it does not work either.</p>

<p>Thank you very much.</p>
