Force no default selection in selectInput()

Question

The Shiny documentation mentions that for selectInput():

selected The value (or, if none was supplied, the title) of the naviga

Answer 1

Faced a similar issue. The solution I found is based of @MKa's answer. You do not want to set multiple=T if your code can't handle multiple values. What I suggest is:

selectInput("molecule",
            "Select Molecule:",
            choices = c("",as.character(mtrl_name)),
            selected = NULL,
            multiple = F
           ) 

And to retrieve the value selected:

if(!is.null(input$molecule))
{
  if(nchar(input$molecule)>1)
  {
    #do your thing..
  }
}

Fixed my problem. Let me know if you found a better solution.