How to make ui.R and server.R to import function and data from other file and plot in ShinyApp

Question

I have a three parts of file that I want to use to make Shiny app.

coolplot.R

This is a code that stores function for plotting.

library(ggplot2)
library(tidyverse)
library(ggrepel)

#-------------------------
# Function 
#-------------------------
plotit <- function (dat, x_thres, y_thres) {
  dat["Significant"] <- ifelse((dat$wt > x_thres | 
                                  dat$mpg > y_thres ), 'NotSignif','Signif')
  p <- ggplot(dat, aes(wt, mpg)) + 
       geom_point(alpha=0.8,size=2.75, aes(color=Significant)) +
       scale_color_manual(values=c("#B94024","#7D8D87")) +
       geom_vline(xintercept= x_thres, colour = '#B94024') + 
       geom_hline(yintercept=y_thres, colour = '#B94024') +
       geom_text_repel(data=subset(dat, wt > x_thres | mpg > y_thres),
                       aes(wt,mpg,label=model),
                       box.padding = unit(0.35, "lines"),
                       point.padding = unit(0.3, "lines") 
                       )  + 
       theme(legend.position="none")  

  return(p)

}

#-------------------------
# Begin main code
#-------------------------
# I literally want to use file as input not 
# default mtcars variable
infile <- "https://gist.githubusercontent.com/seankross/a412dfbd88b3db70b74b/raw/5f23f993cd87c283ce766e7ac6b329ee7cc2e1d1/mtcars.csv"
dat <- read_delim(infile,delim=",", col_types = cols())  
y_thres <- 25
x_thres <- 3
plotit(dat, x_thres, y_thres)

The function basically takes the x-threshold and y-threshold and make the plot like this:

Then I tried to construct the Shiny app that lets the user slide through x-threshold and y-threshold based on the same input data and calling the plotit function. As they slide the vertical, horizontal red lines, and labeling dots will change accordingly.

My Shiny app files are these:

server.R

library(shiny)

# Define server logic for slider examples
function(input, output) {

  # Reactive expression to compose a data frame containing all of
  # the values
  sliderValues <- reactive({

    # Compose data frame
    data.frame(
      Name = c("X-threshold", 
               "Y-threshold"
               ),
      Value = as.character(c(input$integer, 
                             input$integer
                             )), 
      stringsAsFactors=FALSE)
  }) 

  # Show the values using an HTML table
  output$values <- renderTable({
    sliderValues()
  })
}

ui.R

library(shiny)

# Define UI for slider demo application
fluidPage(

  #  Application title
  titlePanel("Sliders"),

  # Sidebar with sliders that demonstrate various available
  # options
  sidebarLayout(
    sidebarPanel(
      # Simple integer interval
      sliderInput("integer", "X-threshold",
                  min=3, max=10, value=1),

      # Simple integer interval
      sliderInput("integer", "Y-threshold",
                  min=10, max=35, value=1)

    ),

    # Show a table summarizing the values entered
    mainPanel(
      tableOutput("values")
      # How can I output the plot from coolplot.R here????
    )
  )
)

My question is how can I make ui.R import function from plot.R and display the plot?

Currently it the Shiny looks like this (minus my comment), in RStudio.

Answer 1

Is what you want? make sure your sliders have unique names please

library(ggplot2)
library(tidyverse)
library(ggrepel)
library(shiny)
#-------------------------
# Function 
#-------------------------
plotit <- function (dat, x_thres, y_thres) {
  dat["Significant"] <- ifelse((dat$wt > x_thres | 
                                  dat$mpg > y_thres ), 'NotSignif','Signif')
  p <- ggplot(dat, aes(wt, mpg)) + 
    geom_point(alpha=0.8,size=2.75, aes(color=Significant)) +
    scale_color_manual(values=c("#B94024","#7D8D87")) +
    geom_vline(xintercept= x_thres, colour = '#B94024') + 
    geom_hline(yintercept=y_thres, colour = '#B94024') +
    geom_text_repel(data=subset(dat, wt > x_thres | mpg > y_thres),
                    aes(wt,mpg,label=model),
                    box.padding = unit(0.35, "lines"),
                    point.padding = unit(0.3, "lines") 
    )  + 
    theme(legend.position="none")  

  return(p)

}

#-------------------------
# Begin main code
#-------------------------
# I literally want to use file as input not 
# default mtcars variable
infile <- "https://gist.githubusercontent.com/seankross/a412dfbd88b3db70b74b/raw/5f23f993cd87c283ce766e7ac6b329ee7cc2e1d1/mtcars.csv"
dat <- read_delim(infile,delim=",", col_types = cols())  
y_thres <- 25
x_thres <- 3
plotit(dat, x_thres, y_thres)



ui <- shinyUI(
  fluidPage(

    #  Application title
    titlePanel("Sliders"),

    # Sidebar with sliders that demonstrate various available
    # options
    sidebarLayout(
      sidebarPanel(
        # Simple integer interval
        sliderInput("integer", "X-threshold",
                    min=3, max=10, value=1),

        # Simple integer interval
        sliderInput("integer2", "Y-threshold",
                    min=10, max=35, value=1)

      ),

      # Show a table summarizing the values entered
      mainPanel(
        tableOutput("values"),
        plotOutput("myplot")
        # How can I output the plot from coolplot.R here????
      )
    )
  )
)

server <- shinyServer(function(input, output, session) {
  # Reactive expression to compose a data frame containing all of
  # the values

  sliderValues <- reactive({

    # Compose data frame
    data.frame(Name = c("X-threshold", "Y-threshold"),
      Value = as.character(c(input$integer, input$integer2)), 
      stringsAsFactors=FALSE)
  }) 

  # Show the values using an HTML table
  output$values <- renderTable({
    sliderValues()
  })

  output$myplot <- renderPlot({

    plotit(dat, input$integer, input$integer2)
  })

})

shinyApp(ui = ui, server = server)

Edit: load the plot function from a file

coolplot.R

library(ggplot2)
library(tidyverse)
library(ggrepel)

#-------------------------
# Function 
#-------------------------
#-------------------------
# Begin main code
#-------------------------
# I literally want to use file as input not 
# default mtcars variable
infile <- "https://gist.githubusercontent.com/seankross/a412dfbd88b3db70b74b/raw/5f23f993cd87c283ce766e7ac6b329ee7cc2e1d1/mtcars.csv"
dat <- read_delim(infile,delim=",", col_types = cols())  

plotit <- function (dat, x_thres, y_thres) {
  dat["Significant"] <- ifelse((dat$wt > x_thres | 
                                  dat$mpg > y_thres ), 'NotSignif','Signif')
  p <- ggplot(dat, aes(wt, mpg)) + 
    geom_point(alpha=0.8,size=2.75, aes(color=Significant)) +
    scale_color_manual(values=c("#B94024","#7D8D87")) +
    geom_vline(xintercept= x_thres, colour = '#B94024') + 
    geom_hline(yintercept=y_thres, colour = '#B94024') +
    geom_text_repel(data=subset(dat, wt > x_thres | mpg > y_thres),
                    aes(wt,mpg,label=model),
                    box.padding = unit(0.35, "lines"),
                    point.padding = unit(0.3, "lines") 
    )  + 
    theme(legend.position="none")  

  return(p)
}

Shiny Part

   library(shiny)
    source("coolplot.R",local = TRUE)$value

    ui <- shinyUI(
      fluidPage(

        #  Application title
        titlePanel("Sliders"),

        # Sidebar with sliders that demonstrate various available
        # options
        sidebarLayout(
          sidebarPanel(
            # Simple integer interval
            sliderInput("integer", "X-threshold",
                        min=3, max=10, value=1),

            # Simple integer interval
            sliderInput("integer2", "Y-threshold",
                        min=10, max=35, value=1)

          ),

          # Show a table summarizing the values entered
          mainPanel(
            tableOutput("values"),
            plotOutput("myplot")
            # How can I output the plot from coolplot.R here????
          )
        )
      )
    )

    server <- shinyServer(function(input, output, session) {
      # Reactive expression to compose a data frame containing all of
      # the values

      # Add the source file of the plot if necessary

      sliderValues <- reactive({

        # Compose data frame
        data.frame(Name = c("X-threshold", "Y-threshold"),
          Value = as.character(c(input$integer, input$integer2)), 
          stringsAsFactors=FALSE)
      }) 

      # Show the values using an HTML table
      output$values <- renderTable({
        sliderValues()
      })

      output$myplot <- renderPlot({

        plotit(dat, input$integer, input$integer2)
      })

    })

    shinyApp(ui = ui, server = server)