R/irec.R

In questionr: Functions to Make Surveys Processing Easier

#' Interactive recoding
#'
#' This function launches a shiny app in a web browser in order to do
#' interactive recoding of a categorical variable (character or factor).
#'
#' @param obj vector to recode or data frame to operate on
#' @param var_name if obj is a data frame, name of the column to be recoded,
#' as a character string possibly without quotes)
#' @return
#' The function launches a shiny app in the system web browser. The recoding
#' code is returned in the onsole
#' when the app is closed with the "Done" button.
#' @examples
#' \dontrun{
#' data(hdv2003)
#' irec()
#' v <- sample(c("Red", "Green", "Blue"), 50, replace = TRUE)
#' irec(v)
#' irec(hdv2003, "qualif")
#' irec(hdv2003, sexe) ## this also works
#' }
#' @import shiny
#' @import rstudioapi
#' @import miniUI
#' @importFrom highr hi_html
#' @importFrom htmltools htmlEscape
#' @export irec



irec <- function(obj = NULL, var_name = NULL) {

  # Deactivate styler cache to avoid blocking message at
  # first launch
  styler::cache_deactivate(verbose = FALSE)

  recoding_styles <- c(
    "Character - minimal" = "charmin",
    "Character - complete" = "charcomp",
    "fct_recode (forcats)" = "forcats"
  )
  selected_recoding_style <- "charmin"
  ## If forcats is loaded
  if (exists("fct_recode")) {
    selected_recoding_style <- "forcats"
  }

  run_as_addin <- ifunc_run_as_addin()

  if (is.null(obj)) {
    if (ifunc_run_as_addin()) {
      context <- rstudioapi::getActiveDocumentContext()
      obj <- context$selection[[1]]$text
      if (obj == "") obj <- NULL
    }
    obj_name <- NULL
    var_name <- NULL
  }
  if (!is.null(obj)) {
    ## If first arg is a string
    if (is.character(obj) && length(obj) == 1) {
      obj_name <- obj
      try(
        {
          obj <- get(obj_name, envir = .GlobalEnv)
        },
        silent = TRUE
      )
    } else {
      obj_name <- deparse(substitute(obj))
    }
    ## If first arg is of the form d$x
    if (grepl("\\$", obj_name)) {
      s <- strsplit(obj_name, "\\$")
      obj_name <- gsub("^\\s*", "", s[[1]][1])
      var_name <- gsub("\\s*$", "", s[[1]][2])
      var_name <- gsub("`", "", var_name)
      obj <- get(obj_name, envir = .GlobalEnv)
    }
    if (inherits(obj, "tbl_df") || inherits(obj, "data.table")) obj <- as.data.frame(obj)

    ## Check if obj is a data frame or a vector
    if (!is.data.frame(obj) && !is.vector(obj) && !is.factor(obj)) {
      stop(sQuote(paste0(obj_name, " must be a vector, a factor or a data frame.")))
    }

    ## If obj is a data.frame
    if (is.data.frame(obj)) {
      ## If var_name is not a character string, deparse it
      is_char <- FALSE
      is_null <- FALSE
      try(
        {
          if (is.character(var_name)) is_char <- TRUE
          if (is.null(var_name)) is_null <- TRUE
        },
        silent = TRUE
      )
      if (!is_char && !is_null) {
        var_name <- deparse(substitute(var_name))
      }
      ## Check if var_name is a column of robject
      if (!is.null(var_name) && !(var_name %in% names(obj))) {
        stop(sQuote(paste0(var_name, " must be a column of ", obj_name, ".")))
      }
    }
  }


  ## Gadget UI
  ui <- miniUI::miniPage(

    ## Page title
    miniUI::gadgetTitleBar(gettext("Interactive recoding", domain = "R-questionr")),
    ## Custom CSS
    tags$style(ifunc_get_css()),
    miniUI::miniTabstripPanel(
      miniUI::miniTabPanel(
        value = "settings",
        gettext("Variable and settings", domain = "R-questionr"), icon = icon("sliders-h"),
        miniUI::miniContentPanel(
          ifunc_show_alert(run_as_addin),

          ## First panel : new variable name and recoding style
          tags$h4(icon("columns"), gettext("Variable to be recoded", domain = "R-questionr")),
          wellPanel(
            fluidRow(
              column(
                6,
                selectizeInput(
                  "obj_name",
                  gettext("Data frame or vector to recode from", domain = "R-questionr"),
                  choices = Filter(
                    function(x) {
                      inherits(get(x, envir = .GlobalEnv), "data.frame") ||
                        is.vector(get(x, envir = .GlobalEnv)) ||
                        is.factor(get(x, envir = .GlobalEnv))
                    }, ls(.GlobalEnv)
                  ),
                  selected = obj_name, multiple = FALSE
                )
              ),
              column(6, uiOutput("varInput"))
            )
          ),
          uiOutput("nblevelsAlert"),
          tags$h4(icon("sliders-h"), gettext("Recoding settings", domain = "R-questionr")),
          wellPanel(
            fluidRow(
              column(4, uiOutput("newvarInput")),
              column(4, selectInput("recstyle", gettext("Recoding style", domain = "R-questionr"),
                recoding_styles,
                selected = selected_recoding_style
              )),
              column(4, uiOutput("outconvUI"))
            )
          ),
          uiOutput("alreadyexistsAlert"),
          uiOutput("loadedforcatsAlert"),
        )
      ),

      ## Second panel : recoding fields, dynamically generated
      miniUI::miniTabPanel(
        value = "recoding",
        gettext("Recoding"), icon = icon("wrench"),
        miniUI::miniContentPanel(
          wellPanel(uiOutput("levelsInput"))
        )
      ),
      ## Third panel : generated code and results checking
      miniUI::miniTabPanel(
        value = "code",
        gettext("Code and result"), icon = icon("code"),
        miniUI::miniContentPanel(
          tags$h4(icon("code"), gettext("Code", domain = "R-questionr")),
          htmlOutput("recodeOut"),
          tags$h4(icon("table"), gettext("Check", domain = "R-questionr")),
          ## Table check tab
          p(
            class = "header",
            gettext("Old variable as rows, new variable as columns.", domain = "R-questionr")
          ),
          tableOutput("tableOut")
        )
      )
    )
  )


  server <- function(input, output, session) {
    if (!is.null(obj_name)) {
      updateSelectizeInput(session, "obj_name", selected = obj_name)
    }
    if (!is.null(var_name)) {
      updateSelectizeInput(session, "var_name", selected = var_name)
    }

    ## reactive first level object (vector or data frame)
    robj <- reactive({
      obj <- get(req(input$obj_name %||% obj_name), envir = .GlobalEnv)
      if (inherits(obj, "tbl_df") || inherits(obj, "data.table")) obj <- as.data.frame(obj)
      obj
    })

    ## reactive variable object (vector or data frame column)
    rvar <- reactive({
      invisible(input$obj_name)
      if (is.data.frame(robj())) {
        return(robj()[[req(input$var_name %||% var_name)]])
      }
      if (is.vector(robj()) || is.factor(robj())) {
        return(robj())
      }
      return(NULL)
    })

    output$outconvUI <- renderUI({
      choices <- c("Character" = "character", "Factor" = "factor", "Numeric" = "numeric")
      if (input$recstyle == "forcats") {
        choices <- c("Factor" = "factor", "Character" = "character", "Numeric" = "numeric")
      }
      selectInput("outconv", gettext("Output type", domain = "R-questionr"), choices)
    })

    ## Text fileds for levels, dynamically generated
    output$levelsInput <- renderUI({
      out <- "<table><tbody>"
      ## List of levels
      if (is.factor(rvar())) {
        levs <- levels(rvar())
      } else {
        levs <- sort(stats::na.omit(unique(rvar())))
      }
      ## Add NA level if there is any NA value
      if (any(is.na(rvar()))) levs <- c(levs, NA)
      ## Generate fields
      for (l in levs) {
        out <- paste0(out, "<tr>")
        out <- paste0(
          out, '<td class="right vertical-align">', htmltools::htmlEscape(l),
          '&nbsp;<span class="glyphicon glyphicon-arrow-right left-sep" aria-hidden="true"></span> &nbsp;</td>'
        )
        label <- l
        l <- gsub(":", "_", l)
        id <- paste0("ireclev_", l)
        ## If the level is NA
        if (id == "ireclev_NA") {
          label <- "NA"
        }
        ## If the level is an empty string
        if (id == "ireclev_") {
          label <- ""
        }
        out <- paste0(out, '<td class="vertical-align">', textInput(id, "", label), "</td>")
        out <- paste0(out, "</tr>")
      }
      out <- paste0(out, "</tbody></table>")
      HTML(out)
    })

    ## If obj is a data frame, column to recode, dynamically generated
    output$varInput <- renderUI({
      if (is.data.frame(robj())) {
        selectizeInput("var_name",
          gettext("Data frame column to recode", domain = "R-questionr"),
          choices = names(robj()),
          selected = var_name,
          multiple = FALSE
        )
      }
    })

    ## Recoded variable name, dynamically generated
    output$newvarInput <- renderUI({
      new_name <- NULL
      if (is.data.frame(robj())) {
        new_name <- paste0(req(input$var_name), "_rec")
      }
      if (is.vector(robj()) || is.factor(robj())) {
        new_name <- paste0(req(input$obj_name), "_rec")
      }
      if (!is.null(new_name)) {
        textInput(
          "newvar_name",
          gettext("New variable name", domain = "R-questionr"),
          new_name
        )
      }
    })

    output$nblevelsAlert <- renderUI({
      if (length(unique(rvar())) > 50) {
        div(
          class = "alert alert-warning alert-dismissible",
          HTML('<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>'),
          HTML(gettext("<strong>Warning :</strong> The variable to be recoded has more than 50 levels.", domain = "R-questionr"))
        )
      }
    })

    output$loadedforcatsAlert <- renderUI({
      if (input$recstyle == "forcats" && !exists("fct_recode")) {
        div(
          class = "alert alert-warning alert-dismissible",
          HTML('<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>'),
          HTML(gettext("<strong>Warning :</strong> The <tt>forcats</tt> package must be installed and loaded for the generated code to be run.", domain = "R-questionr"))
        )
      }
    })

    output$alreadyexistsAlert <- renderUI({
      exists <- FALSE
      if (is.data.frame(robj()) && req(input$newvar_name) %in% names(robj())) {
        exists <- TRUE
      }
      if (is.vector(robj()) && exists(req(input$newvar_name), envir = .GlobalEnv)) {
        exists <- TRUE
      }
      if (exists) {
        div(
          class = "alert alert-warning alert-dismissible",
          HTML('<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>'),
          HTML(gettext("<strong>Warning :</strong> This new variable already exists.", domain = "R-questionr"))
        )
      }
    })

    ## Reactive source variable name
    src_var <- reactive({
      if (is.data.frame(robj())) {
        ## Formatted source variable name
        var_name <- req(input$var_name)
        if (make.names(var_name) != var_name) {
          var_name <- paste0('`', var_name, '`')
        }
        result <- sprintf("%s$%s", req(input$obj_name), var_name)
      }
      if (is.vector(robj()) || is.factor(robj())) {
        result <- req(input$obj_name)
      }
      return(result)
    })

    ## Format a value from a text input to code
    get_value <- function(val) {
      if (is.null(val)) {
        return()
      }
      if (val %in% c("NA", "TRUE", "FALSE")) {
        return(val)
      }
      val <- gsub("^\\s+|\\s+$", "", val)
      ## Encoding conversion for Windows
      Encoding(val) <- "UTF-8"
      val <- enc2native(val)
      val <- utils::capture.output(dput(val))
      val
    }

    ## Generate character style recoding code
    generate_code_character <- function(dest_var, style) {
      out <- ""
      ## List levels
      if (is.factor(rvar())) {
        levs <- levels(rvar())
      } else {
        levs <- sort(stats::na.omit(unique(rvar())))
        levs <- as.character(levs)
      }
      if (any(is.na(rvar()))) levs <- c(levs, NA)
      for (l in levs) {
        l_clean <- gsub(":", "_", l)
        value <- get_value(input[[paste0("ireclev_", l_clean)]])
        ## If minimal style, values unchanged are omitted
        if (style == "min" && !is.null(input[[paste0("ireclev_", l_clean)]])) {
          if (is.na(l) && value == "NA") next
          if (!is.na(l)) {
            if (l == input[[paste0("ireclev_", l_clean)]]) next
            if (l == "" && value == "\"\"") next
          }
        }
        ## NA values
        if (is.na(l)) {
          out <- paste0(out, sprintf("%s[is.na(%s)] <- %s\n", dest_var, src_var(), value))
        }
        ## Empty strings
        if (!is.na(l) && l == "") {
          out <- paste0(out, sprintf('%s[%s == ""] <- %s\n', dest_var, src_var(), value))
        }
        ## Normal values
        if (!is.na(l) && l != "") {
          out <- paste0(out, sprintf(
            "%s[%s == %s] <- %s\n",
            dest_var, src_var(),
            utils::capture.output(dput(l)),
            value
          ))
        }
      }
      ## Optional output conversion
      if (input$outconv == "factor") out <- paste0(out, sprintf("%s <- factor(%s)\n", dest_var, dest_var))
      if (input$outconv == "numeric") out <- paste0(out, sprintf("%s <- as.numeric(%s)\n", dest_var, dest_var))
      ## If any recoding has been done
      if (out != "") {
        ## Create new variable
        if (!is.character(rvar())) {
          out <- paste0(sprintf("%s <- as.character(%s)\n", dest_var, src_var()), out)
        } else if (dest_var != src_var()) {
          out <- paste0(sprintf("%s <- %s\n", dest_var, src_var()), out)
        }
        ## Initial comment
        if (dest_var != src_var()) {
          out <- paste0(gettextf("## Recoding %s into %s\n", src_var(), dest_var, domain = "R-questionr"), out)
        } else {
          out <- paste0(gettextf("## Recoding %s\n", src_var(), domain = "R-questionr"), out)
        }
      }
      out
    }

    ## Generate recoding code for forcats
    generate_code_forcats <- function(dest_var) {
      out <- ""
      ## List levels
      if (is.factor(rvar())) {
        levs <- levels(rvar())
      } else {
        levs <- sort(stats::na.omit(unique(rvar())))
        levs <- as.character(levs)
      }
      if (any(is.na(rvar()))) levs <- c(levs, NA)
      out <- ""
      na_recode <- ""
      has_recode_to_na <- FALSE
      for (l in levs) {
        l_clean <- gsub(":", "_", l)
        value <- get_value(input[[paste0("ireclev_", l_clean)]])
        ## Values unchanged are omitted
        if (is.na(l) && value == "NA") next
        if (!is.na(l)) {
          if (l == input[[paste0("ireclev_", l_clean)]]) next
          if (l == "" && value == "\"\"") next
        }
        ## We can't recode to empty string
        if (value == '""') {
          value <- '"-"'
        }
        ## NA values
        if (is.na(l)) {
          na_recode <- value
        }
        ## Recode to NA
        if (value == "NA") {
          value <- "NULL"
          has_recode_to_na <- TRUE
        }
        ## Normal values
        if (!is.na(l)) {
          if (out != "") out <- paste0(out, ",\n")
          out <- paste0(out, sprintf(
            "%s = %s",
            value,
            utils::capture.output(dput(l))
          ))
        }
      }

      ## fct_recode
      if (out != "") {
        source <- src_var()
        if (na_recode != "" && has_recode_to_na) {
          source <- dest_var
        }
        ## Input conversion if numeric
        if (is.numeric(rvar())) {
          out <- paste0(sprintf("%s <- %s %%>%%\n  as.character() %%>%%\n fct_recode(\n", dest_var, source), out)
        } else {
          out <- paste0(sprintf("%s <- %s %%>%%\n  fct_recode(\n", dest_var, source), out)
        }
        out <- paste0(out, ")")
      }

      ## fct_explicit_na
      if (na_recode != "") {
        if (out != "" && !has_recode_to_na) {
          out <- paste0(out, sprintf(" %%>%%\n  fct_explicit_na(%s)", na_recode))
        } else {
          out <- paste0(sprintf("%s <- %s %%>%%\n  fct_explicit_na(%s)\n", dest_var, src_var(), na_recode), out)
        }
      }

      ## Optional output conversion
      if (input$outconv == "character") out <- paste0(out, " %>%\n  as.character()\n")
      if (input$outconv == "numeric") out <- paste0(out, " %>%\n  as.character() %>%\n  as.numeric()\n")

      ## Initial comment
      comment <- ""
      if (out != "" || na_recode != "") {
        if (dest_var != src_var()) {
          comment <- gettextf("## Recoding %s into %s\n", src_var(), dest_var, domain = "R-questionr")
        } else {
          comment <- gettextf("## Recoding %s\n", src_var(), domain = "R-questionr")
        }
      }
      out <- paste0(comment, out)
      out
    }


    ## Call recoding code generation function based on style
    generate_code <- function(check = FALSE) {
      if (is.data.frame(robj())) {
        dest_var <- req(input$newvar_name)
        if (make.names(dest_var) != dest_var) {
          dest_var <- paste0('`', dest_var, '`')
        }
        dest_var <- sprintf("%s$%s", req(input$obj_name), dest_var)
      }
      if (is.vector(robj()) || is.factor(robj())) {
        dest_var <- req(input$newvar_name)
      }
      ## if check, create temporary variable for check table
      if (check) dest_var <- ".irec_tmp"

      ## Invoke recoding code generation function
      recstyle <- input$recstyle
      if (recstyle == "charcomp") {
        return(generate_code_character(dest_var, style = "comp"))
      }
      if (recstyle == "charmin") {
        return(generate_code_character(dest_var, style = "min"))
      }
      if (recstyle == "forcats") {
        return(generate_code_forcats(dest_var))
      }
    }

    ## Generate the code in the interface
    output$recodeOut <- renderText({
      ## Header
      if (is.data.frame(robj())) {
        header <- HTML(gettextf("<p class='header'>Recoding <tt>%s</tt> from <tt>%s</tt> of class <tt>%s</tt>.</p>",
          req(input$var_name), req(input$obj_name), class(rvar()),
          domain = "R-questionr"
        ))
      }
      if (is.vector(robj()) || is.factor(robj())) {
        header <- HTML(gettextf("<p class='header'>Recoding <tt>%s</tt> of class <tt>%s</tt>.</p>",
          req(input$obj_name), class(rvar()),
          domain = "R-questionr"
        ))
      }
      ## Generate code
      out <- generate_code()
      out <- styler::style_text(out)
      ## Generated code syntax highlighting
      out <- paste(highr::hi_html(out), collapse = "\n")
      ## Final paste
      out <- paste0(header, "<pre class='r'><code class='r' id='codeout'>", out, "</code></pre>")
      out
    })


    # Handle the Done button being pressed.
    observeEvent(input$done, {
      ## Generate code
      out <- generate_code()
      out <- styler::style_text(out)
      out <- paste(out, collapse = "\n")
      if (run_as_addin) {
        rstudioapi::insertText(text = out)
      }
      out <- paste0(
        gettext("\n-------- Start recoding code --------\n\n", domain = "R-questionr"),
        out,
        gettext("\n--------- End recoding code ---------\n", domain = "R-questionr")
      )
      cat(out)
      stopApp()
    })

    # Handle the Cancel button being pressed.
    observeEvent(input$cancel, {
      invisible(stopApp())
    })

    ## Generate the check table
    output$tableOut <- renderTable(
      {
        ## Generate the recoding code with a temporary variable
        code <- generate_code(check = TRUE)
        if (!exists("fct_recode") && input$recstyle == "forcats") {
          return(NULL)
        }
        if (code != "") {
          ## Eval generated code
          eval(parse(text = code), envir = .GlobalEnv)
          ## Display table
          tab <- table(rvar(), get(".irec_tmp"), useNA = "always")
          rownames(tab)[is.na(rownames(tab))] <- "NA"
          colnames(tab)[is.na(colnames(tab))] <- "NA"
        } else {
          ## Abort, return nothing
          req(FALSE)
        }
        as.data.frame.matrix(tab)
      },
      rownames = TRUE
    )
  }


  runGadget(ui, server, viewer = dialogViewer("irec", width = 800, height = 700))
}