Interactive directory input in Shiny app (R)
<p>I am building a shiny app that requires a user to select a folder on the local machine, which contains the files to be processed by the app. </p>

<p>I am using a solution proposed <a href="https://github.com/wleepang/shiny-directory-input" rel="noreferrer">here</a>. This works fine on a local machine, but does not work if the app is deployed to a shinyapps server. 
The author of this solution confirmed that it was only designed to work with local Shiny apps, since it makes OS shell calls to display a directory dialog.</p>

<p>I am wondering if there is a different solution for directory dialog, which will work on the deployed Shiny apps (I am deploying to shinyapps.io). </p>

<p>Edited: Notice that I cannot use <a href="http://shiny.rstudio.com/reference/shiny/latest/fileInput.html" rel="noreferrer">fileInput</a> interface for two reasons:</p>

<ol>
<li>The users of the app are not technical people and they do not know which files inside the folder are used by the app. </li>
<li>The selected folder may contain other folders within which the needed files reside, such that it is impossible to select all files at once, even if the fileInput interface has the <code>multiple</code> option enabled. </li>
</ol>

<p>The folder/files structure is not something I can change, it is downloaded AS IS from a medical device and therefore the only thing I can expect from the users is to specify the parent folder and the rest should be done inside the R code. </p>