In-line MathJax equations not rendering on Shiny app hosted at shinyapps.io

Question

I have a shiny app that includes MathJax equations and some script to allow for in-line equations. It works fine the RStudio IDE but not when hosted on shinyapps.io.

I have narrowed down interference to a shinymanager::secure_app() function. It may have something to do with the head_auth argument within secure_app(), but I cannot figure it out.

For example:

library(shiny)
library(shinymanager)

# credentials <- data.frame(
#   user = c(""),
#   password = c(""),
#   stringsAsFactors = FALSE
# )


ui <- 
  # secure_app( 
    fluidPage(

    sidebarLayout(
        sidebarPanel(),

        mainPanel(
          tags$div(HTML(
            "<script type='text/x-mathjax-config' >
            MathJax.Hub.Config({
            tex2jax: {inlineMath: [['$','$']]}
                              });
            </script >
            ")),
          p(withMathJax("$$n_{\\sf larvae_0} \\sim {\\sf binomial}(n_{\\sf egg}, \\pi_{\\sf egg})$$"), style="text-align: center; font-size:20px;"),
          
          
          p(withMathJax("where $n_{\\sf larvae_0}$ is the number of age-0 larvae, 
                          $\\pi_{\\sf egg}$ is the Beverton-Holt estimated egg to larva survival probability... ")),
        )
    )
)
# )


server <- function(input, output) {
  secure_server(check_credentials = check_credentials(credentials))
}

shinyApp(ui = ui, server = server)

returns text that includes in-line equations in both RStudio and when hosted (published) to shinyapps.io:

When I activate the secure_app() part, the in-line text still renders properly up in RStudio IDE viewer, but DOES NOT render as an equation in the hosted app on shinyapps.io:

library(shiny)
library(shinymanager)

credentials <- data.frame(
  user = c(""),
  password = c(""),
  stringsAsFactors = FALSE
)


ui <- 
  secure_app(
    fluidPage(

    sidebarLayout(
        sidebarPanel(),

        mainPanel(
          tags$div(HTML(
            "<script type='text/x-mathjax-config' >
            MathJax.Hub.Config({
            tex2jax: {inlineMath: [['$','$']]}
                              });
            </script >
            ")),
          p(withMathJax("$$n_{\\sf larvae_0} \\sim {\\sf binomial}(n_{\\sf egg}, \\pi_{\\sf egg})$$"), style="text-align: center; font-size:20px;"),
          
          
          p(withMathJax("where $n_{\\sf larvae_0}$ is the number of age-0 larvae, 
                          $\\pi_{\\sf egg}$ is the Beverton-Holt estimated egg to larva survival probability... ")),
        )
    )
)
)


server <- function(input, output) {
  secure_server(check_credentials = check_credentials(credentials))
}

shinyApp(ui = ui, server = server)

Answer 1

Changing the in-line math delimiters to something other than $ resolves the issue, although it is not clear what the conflict is with using $. Following this answer, we can add \\( \\) as a delimiter:

  tags$div(HTML("<script type='text/x-mathjax-config' >
        MathJax.Hub.Config({
        tex2jax: {inlineMath: [['$','$'], ['\\\\(','\\\\)']]}
        });
        </script >
        ")),

Now

p(withMathJax("where \\(n_{\\sf larvae_0}\\) is the number of age-0 larvae, 
              \\(\\pi_{\\sf egg}\\) is the Beverton-Holt estimated egg to larva survival probability... ")),

p(withMathJax("where $n_{\\sf larvae_0}$ is the number of age-0 larvae, 
              $\\pi_{\\sf egg}$ is the Beverton-Holt estimated egg to larva survival probability... ")),

Results in them both working in the RStudio IDE:

But only the \\( \\) delimiter works once the app is published (hosted) on shinyapps.io: