app.R

# Load libraries ----------------------------------------------------------

list_of_packages <- c("shiny", "dplyr", "stringr", "DT")
new_packages <- list_of_packages[!(list_of_packages %in% installed.packages()[,"Package"])]
if(length(new_packages)) install.packages(new_packages)

library(shiny)
library(dplyr)
library(stringr)
library(DT)


# Import data -------------------------------------------------------------


df_thoughts_long <- readRDS("df_thoughts_long")
labels <- readRDS("labels")


# App ---------------------------------------------------------------------


# Client-side

ui <- fluidPage(
  # Application title
  titlePanel("Topic explorer"),

  # Sidebar with a topic selector
  sidebarLayout(
    sidebarPanel(
      selectInput("topic_number",
        "Select topic number",
        choices = seq(1:90)
      ),
      textOutput("heading")
    ),

    # Show table with sample texts
    mainPanel(
      tableOutput("topic_table")
    )
  )
)

# Server-side

server <- function(input, output) {

  # define table
  output$topic_table <- renderTable({
    # get the right column based on input
    df_thoughts_long %>%
      # filter topic number
      filter(topic == input$topic_number) %>%
      # discard topic column
      select(-topic) %>%
      # add row number
      mutate(id = row_number()) %>%
      # move it to the front
      relocate(id, .before = title)
  })

  # get heading with topic frex terms
  output$heading <- renderText({
    paste0("Topic ", input$topic_number, ": ", str_c(labels$frex[eval(parse(text = input$topic_number)), 1:10], collapse = ", "))
  })
}

# Run the application
shinyApp(ui = ui, server = server)