absolute newbie request-- how do I include math/greek/special chacters in shiny labels?

[ma...@humboldt.edu]

Hi all--

I'm building my first shiny application and need to replace words like "alpha" in my slider labels with Greek characters, and use italic fonts and subscripts/superscripts as well.  Can someone point me in the right direction?

Best regards,
--Mike C.

[Yihui Xie]

With the current development version
(https://github.com/rstudio/shiny), you can use MathJax in ui.R if you
understand LaTeX, e.g.

basicPage(
withMathJax(),
sliderInput('foo', label = '\\( \\alpha^2 \\)')
)


Regards,
Yihui

[Patrick Toche]

@ Yihui,

This sounds great, do you have a minimum working example?

The OP stated "absolute newbie"  ;-)

Here is my experience: argument "metaHandler" is missing, with no default

Not sure what that is referring to. 

Another question: is there a way to install the development version of shiny alongside the stable version? Can I just rename it shiny-dev and call library("shiny-dev"), would that work? Thanks.

runApp("shiny-latex")

Listening on port 4903

Error in tag("div", list(...)) : could not find function "withMathJax"

This is to install the development version:

if (!require("devtools"))

  install.packages("devtools")

devtools::install_github("shiny", "rstudio")

runApp("shiny-latex")

Listening on http://127.0.0.1:6091

Error in handler(req) : 

  argument "metaHandler" is missing, with no default

Here is an attempt at a MWE:

# ui.R

basicPage( 

  withMathJax(), 

  sliderInput(inputId = 'foo', label = '\\( \\alpha^2 \\)', value = 0, min = -1, max = 1) 

) 

# server.R 

shinyServer(

  function(input, output) { # adding a session argument didn't help

     ##

  }

)

[Stéphane Laurent]

@Patrick: devtools::install_github("shiny", "rstudio", ref="dev") for the development version.

[Patrick Toche]

Thanks Stéphane, I think I got the dev version working. The code I used to install the dev version is taken from the page that Yihui links to in his message, namely this:

if (!require("devtools"))

  install.packages("devtools")

devtools::install_github("shiny", "rstudio")

worked ok.

I'm guessing that it amounts to the same as your suggestion.  Does the ui.R and server.R code I posted work for you?

 devtools::install_github("shiny", "rstudio", ref="dev")

Installing github repo shiny/dev from rstudio

Downloading shiny.zip from https://github.com/rstudio/shiny/archive/dev.zip

Error: client error: (404) Not Found

[Yihui Xie]

devtools::install_github("shiny", "rstudio") just installs the
development version -- there is no branch named "dev", so ref="dev"
does not make sense.

Regards,
Yihui

[Patrick Toche]

@ Yihui,

I'm getting: 

argument "metaHandler" is missing, with no default

any ideas?

Thanks. 

[Yihui Xie]

In ui.R, you have to call shinyUI(), e.g.

# ui.R
shinyUI(basicPage(

withMathJax(),
sliderInput(inputId = 'foo', label = '\\( \\alpha^2 \\)', value = 0,
min = -1, max = 1)

))


Regards,
Yihui

[Patrick Toche]

That was so silly!

I had my eyes focusing on detail and missed the big picture.

Thanks a lot Yihui!

Patrick.