app.R

library(DT)
library(rvest)
library(dplyr)
library(shiny)
library(purrr)
library(tidytext)
library(echarts4r)

response <- httr::GET(
  "https://api.weforum.org/v1/articles?page%5Bnumber%5D=2&page%5Bsize%5D=100"
)

content <- httr::content(response)

titles <- content$data %>% 
  map("attributes") %>% 
  map("title") %>% 
  unlist() 

link <- content$data %>% 
  map("attributes") %>% 
  map("website_endpoint") %>% 
  unlist()

data <- data.frame(
  title = titles,
  link = link
)

ui <- fluidPage(
  theme = shinythemes::shinytheme("paper"),
  div(
    class = "container",
    h3("WEF Programming test"),
    p("Select an article to see a wordcloud of its content"),
    hr(),
    fluidRow(
      column(
        3, DTOutput("table")
      ),
      column(
        9, echarts4rOutput("cloud", height = "80vh")
      )
    )
  )
)

server <- function(input, output, session) {
  
  output$table <- renderDT({
    data %>% 
      mutate(
        title = paste0("<a href='", link, "' target='_blank'>", title, "</a>")
      ) %>% 
      select(title) %>% 
      datatable(options = list(dom = "p"), escape = FALSE, selection = "single")
  })
  
  output$cloud <- renderEcharts4r({
    
    req(input$table_rows_selected)
    
    data %>% 
      slice(input$table_rows_selected) %>% 
      pull(link) %>% 
      as.character() %>% 
      read_html() %>% 
      html_nodes(".article-body") %>% 
      html_text() %>% 
      gsub("\n", "", .) %>% 
      tibble(
        text = .
      ) %>% 
      unnest_tokens(word, text) %>% 
      anti_join(stop_words, by = "word") %>% 
      count(word, sort = T) %>% 
      slice(1:150) %>% 
      e_color_range(n, color, colors = rev(c("#bf444c", "#d88273", "#f6efa6"))) %>% 
      as.data.frame() %>% 
      e_charts() %>% 
      e_cloud(word, n, color) 
  })
  
}

shinyApp(ui, server)