Custom HTML links in Shiny

This application makes use of data downloaded from a website I use a lot in my daily work, Patient Opinion (patientopinion.org.uk/). Patient Opinion lets users of health services tell their stories, and my organization makes extensive use of it to gather feedback about our services and improve them. This application uses data downloaded from the site and allows users to see the rate at which stories are posted that relate to different parts of the organization. A custom HTML button will take them straight from the application and onto the search page on Patient Opinion for that service area.

ui.R

Let's take a look at the ui.R file first:

#################################
### custom HTML output - ui.R ###
#################################

library(shiny)
shinyUI(fluidPage(
  tags$head(HTML("<link href='http://fonts.googleapis.com/css?family=Jura' rel='stylesheet' type='text/css'>")),

  h2("Custom HTML", style = "font-family: 'Jura'; color: green; font-size:...