inst/server.R

In reinholdsson/ColdbirHelpServer: Coldbir Help Server

shinyServer(function(input, output) {

  data <- reactive({
    dims <- .VARIABLES[id == as.integer(input$dimension)]$dims[[1]]
    data <- .CDB[input$variable, dims]
    return(data)
  })
  
  summaryData <- reactive({
    x <- data()
    if (is.factor(x)) {
      x <- summary(x)
      x <- data.frame("Variable" = names(x), "N" = x)
      x <- x[order(-x$N), ]
    } else {
      stats <- c(
        "N" = length(x),
        "Min" = min(x, na.rm = TRUE),
        "Median" = median(x, na.rm = TRUE),
        "Mean" = mean(x, na.rm = TRUE),
        "Max" = max(x, na.rm = TRUE),
        "Sd" = sd(x, na.rm = TRUE),
        "NA's" = length(x[is.na(x)])
      )
      x <- data.frame("Measure" = names(stats), "Value" = stats)
    }
    return(x)
  })
  
  output$dimension <- renderUI({
    x <- .VARIABLES[variable == input$variable]
    dims <- x$id
    names(dims) <- x$dims_label
    
    selectInput("dimension", "", sort(dims, decreasing = T), selected = max(names(dims)))
  })
  
  output$charts <- renderPlot({
    
    x <- data()
    
    if (is.factor(x)) {
      x <- table(x)
      x <- as.data.frame(x)
      p <- ggplot(x) + geom_point(aes(x = x, y = Freq)) + coord_flip() + labs(title = "Frequency")
    } else {
      
      # Sample for large vectors
      if (length(x) > 100000) {
        x <- sample(x, 100000)
      }
      
      x <- data.table(x = x)
      p <- ggplot(x) + geom_density(aes(x = x), fill = "lightblue") + labs(title = "Density")
    }
    
    p <- p + xlab(NULL) + ylab(NULL) + theme_tufte() + theme(legend.position="none")
    print(p)
  })
  
  output$docs <- renderText({
    tryCatch(
      markdown::markdownToHTML(text = list_to_md(get_doc(.CDB, input$variable)), fragment.only = TRUE),
      error = function(e) "Documentation is missing!")
  })
  
  output$downloadData <- downloadHandler(
    filename = function() {
      paste('data-', Sys.Date(), '.csv', sep='')
    },
    content = function(file) {
      write.csv2(summaryData(), file, row.names = F)
    }
  )
  
  output$table <- renderTable({
    head(summaryData(), 10)
  }, include.rownames = F)

  output$db_stats <- renderTable({
      
      info <- file.info(get_path(.CDB))
      data.frame(
        key = c(
            "path",
            "size",
            "mode",
            "mtime",
            "ctime",
            "atime",
            "variables", 
            "variables (all files)",
            "unique dimensions"
        ),
        value = c(
            get_path(.CDB),
            info$size,
            info$mode,
            as.character(info$mtime),
            as.character(info$ctime),
            as.character(info$atime),
            length(.UNIQUE_VARIABLES), 
            nrow(.VARIABLES),
            length(unique(.VARIABLES$dims_label))
        )
      )
  }, include.rownames = F, include.colnames = F)
  
})