fileInput(inputId, label, multiple = FALSE, accept = NULL, width = NULL)input slot that will be used to access the value.NULL for no label.'400px', or '100%';
see validateCssUnit.actionButton,
actionLink; animationOptions,
sliderInput;
checkboxGroupInput;
checkboxInput; dateInput;
dateRangeInput; numericInput;
passwordInput; radioButtons;
selectInput, selectizeInput;
submitButton; textInput