Running JS Commands on a Shiny Markdown Document - r

Question

I am trying to implement Stephane Laurent's solution to requiring a minimum number of selections for a picker input in a Shiny Markdown document but cannot figure out how to run the java script component. Can anyone tell me where I place the js and tags$head... objects to make this run correctly?
Solution Using a Traditional Shiny App
library(shiny)
library(shinyWidgets)
js <- "
$(document).ready(function(){
$('#somevalue').on('show.bs.select', function(){
$('a[role=option]').on('click', function(e){
var selections = $('#somevalue').val();
if(selections.length === 1 && $(this).hasClass('selected')){
e.stopImmediatePropagation();
};
});
}).on('hide.bs.select', function(){
$('a[role=option]').off('click');
});
});"
ui <- fluidPage(
tags$head(tags$script(HTML(js))),
pickerInput(
inputId = "somevalue",
label = "A label",
choices = c("a", "b"),
selected = "a",
multiple = TRUE
),
verbatimTextOutput("value")
)
server <- function(input, output) {
output$value <- renderPrint(input$somevalue)
}
shinyApp(ui, server)
Shiny Markdown Document Wrapper Doesn't Work
---
runtime: shiny
output:
html_document
---
```{r echo = F, message = F, warning = F, error = F}
library(shiny)
library(shinyWidgets)
js <- "
$(document).ready(function(){
$('#somevalue').on('show.bs.select', function(){
$('a[role=option]').on('click', function(e){
var selections = $('#somevalue').val();
if(selections.length === 1 && $(this).hasClass('selected')){
e.stopImmediatePropagation();
};
});
}).on('hide.bs.select', function(){
$('a[role=option]').off('click');
});
});"
tags$head(tags$script(HTML(js)))
pickerInput(
inputId = "somevalue",
label = "A label",
choices = c("a", "b"),
selected = "a",
multiple = TRUE
)
```

Answer 1

I have not tried, but I think you can include a JavaScript chunk:
```{js}
$(document).ready(function(){
$('#somevalue').on('show.bs.select', function(){
$('a[role=option]').on('click', function(e){
var selections = $('#somevalue').val();
if(selections.length === 1 && $(this).hasClass('selected')){
e.stopImmediatePropagation();
};
});
}).on('hide.bs.select', function(){
$('a[role=option]').off('click');
});
});
```