Implement Document Picker in swift (iOS)
<p>I want to pick a file of any type(.pdf, .docs, .xlsx, .jpeg, .txt, .rtf, etc) functionality in my iOS app. On clicking on <strong>Upload</strong> button, I want my app to open a directory and select files(<code>DocumentsPicker</code>)</p>

<pre><code>@IBAction pickDocument(sender: UIButton) {
    //Open Document Picker
}
</code></pre>

<p>Any approach to do so in <code>Swift</code>?</p>