Apologies for the delayed response here. File Inputs to Parameterized R Markdown reports are not very customizable today, and unfortunately there is no way to set the option in question for the selector made available in the Connect UI. I have opened an issue internally for tracking. At present the only workarounds I can come up with are:
- use a Shiny application or Shiny document (R Markdown document with a Shiny runtime).
- save the files onto an internal webserver or share drive, and have a text input for a filepath or URL. R code would then be required to "go get" the file and pull it into Connect when rendering.