trelliscopejs_shiny.R

# need to install dev version of trelliscopejs
# remotes::install_github("hafen/trelliscopejs@dev")

library(shiny)
library(dplyr)
library(tidyr)
library(ggplot2)
library(trelliscopejs)

ui <- fixedPage(
  title = "Test Shiny App with TrelliscopeJS",
  fixedRow(
    column(width = 4,
      tags$br(),
      selectInput("example",
        label = "Choose Example", choices = c("example 1", "example 2")),
      actionButton("make_trelliscope", "Create Trelliscope Display")
    ),
    column(
      width = 8,
      # dimensions for trelliscopeOutput should be in units of "px"
      trelliscopeOutput("trelliscope_out",
        width = "800px", height = "800px")
    )
  )
)

server <- function(input, output, session) {
  output$trelliscope_out <- renderTrelliscope({
    if (input$make_trelliscope == 0) {
      NULL
    } else {
      ex <- isolate(input$example)
      if (ex == "example 1") {
        x <- factor(LETTERS[1:4])
        names(x) <- letters[1:4]
        data_year_date <- data.frame(
          year = structure(seq(1950, 1989, 1), class = "Date"),
          var = rep(x, 10), y = seq(1, 200, 5))
        # trelliscope displays must go in www/...
        # also, can do self_contained = TRUE, but this is not advised
        p <- ggplot(data_year_date, aes(year, y)) + geom_point() +
          facet_trelliscope(~ var, path = "www/tr_example1")
        # if output is from using facet_trelliscope, need to print it
        print(p)
      } else if (ex == "example 2") {
        mpg %>%
          group_by(manufacturer, class) %>%
          nest() %>%
          mutate(
            panel = map_plot(data, ~
              qplot(cty, hwy, data = .) + xlab("cty") + ylab("hwy") +
                xlim(7, 37) + ylim(9, 47) + theme_bw())) %>%
          trelliscope(name = "tidy_gg", path = "www/tr_example2",
            nrow = 2, ncol = 2)
      } else {
        NULL
      }
    }
  })
}

shinyApp(ui = ui, server = server)