purge_shiny_code: Remove shiny-specific code from callstack

In dgkf/scriptgloss: Functionality for creating static scripts from shiny apps

Description

walk an expression, call or list, replacing canonical shiny server functions with R script equivalent code.

Usage

purge_shiny_code(x)

Arguments

x	a call, or expression to strip of shiny-specific functions

Value

the same call or expression, with shiny runtime-specific functionality stripped and replaced with code that will evaluate within an R script.

Note

specifically, a few shiny functions built around a reactive javascript context are reconstructed as base R functions:

• my_reactive_value <- reactive({ ... }) will become my_reactive_value <- function() { ... }

• All shiny render functions (output$my_output <- render*({ ... })) will become output$my_output <- function() { ... }

• calls to observeEvent() becomes NULL

• calls to observe() becomes NULL

Examples

library(shiny)

code <- quote({
  output$plot <- renderPlot({
    plot(x = mtcars[[input$x]],
         y = mtcars[[input$y]])
  })
  observeEvent(input$give_me_a_happy_message, {
    "you're a great person!"
  })
  output$code <- renderPrint({
    generate_static_code(srv, 'plot')
  })
})

scriptgloss:::purge_shiny_code(code)

dgkf/scriptgloss documentation built on June 8, 2019, 8:43 p.m.