I have a published service with links to folders that are for internal network drive use only. For example, the network folder path in windows explorer on my desktop is I:Street TreePermits(permit number). I ran a field calculator on to show the field as file://I:Street TreePermits(permit number). If I open that link in a web browser, it will open the folder.
My goal is to show the hyperlink and open the folder in Flex Viewer or an ArcGIS online web app template, but these applications will not recognize the file://IStreet TreePermits(permit number) as a web URL. I tried specifying in Flex Viewer the field as a hyperlink, and the web browser does not recognize as a link.
I am aware that the link will not work outside the internal network, which is fine for my purposes.
I've never used Flex Viewer, but I just went through a similar situation with ArcGIS Online. Apparently, web browsers don't normally allow local links for security reasons. You could try installing a LocalLinks plugin or add-on depending on the browser you're using:
Firefox - https://addons.mozilla.org/en-us/firefox/addon/locallink/
I did not try this method personally, since I didn't want to install anything on my work computer. Instead, I stored all of the files I needed on my company's file share website, which created a web URL I could copy/paste for each file.
You can do the same thing with a Dropbox account, instructions here: http://blogs.esri.com/esri/arcgis/2013/07/17/using-dropbox-files-in-arcgis-online/
This was the best solution I could find without having to program.