KoBo Data Viewer (Shiny)

server.R

# server.R

library(shiny)

shinyServer(function(input, output) {
  
  ## Start by creating a reactive version of the dataset listing. This
  ##   will then let us access the data for use in dynamically creating
  ##   the listing of the available datasets. We only need the "id"
  ##   and "title" datasets.
  
  my_data <- reactive({
    input$listDatasets
    isolate({
     user_name <- if (input$username == "NULL") NULL else input$username
      password <- if (input$password == "NULL") NULL else input$password
    })
    isolate({
      out <- kobo_datasets(
        user = c(user_name, password), 
        api = input$api)[, c("id", "title"), with = FALSE]
    })
  })
  
  ## This is for the datatable output
  
  output$datasetsAvailable <- renderDataTable({
    datatable(my_data())
  })
  
  ## This creates the dropdown UI for the sidebar. The values are 
  ##   automatically populated with the "id" and "title" values from
  ##   the my_data dataset, which must be accessed using my_data()
  
  output$select_dataset <- renderUI({
    dat <- my_data()
    selectInput("select", label = "Select Dataset", 
                choices = setNames(dat$id, dat$title), 
                selected = 1, selectize = TRUE)
  })
  
  ## This downloads the requested dataset to your global environment,
  ##   and displays it in the "Requested Dataset" tab in the UI.
  
  output$datasetRequested <- renderDataTable({
    input$loadDataset
    isolate({
      user_name <- if (input$username == "") NULL else input$username
      password <- if (input$password == "") NULL else input$password
      out <- kobo_data_downloader(
        input$select, c(user_name, password), input$api)
    })
    datatable(out, filter = "top")
  })
})

ui.R

# ui.R

## Required packages
library(shiny)
library(DT)
library(koboloadeR)

## Create the user interface
## One row across the top for logging in and retrieving the datasets
##   available via those login credentials.
## A sidebar panel that lets you select a dataset to load.
## A main panel that has two tabs, one that shows the ID and names of
##   the datasets available, one that will show the contents of the
##   requested dataset.

x <- TRUE

shinyUI(fluidPage(
  headerPanel("KoBo Data Viewer"),
  fluidRow(
    column(3, textInput("username", label = "Username", value = "")),
    column(3, passwordInput("password", label = "Password", value = "")),
    column(4, textInput("api", label = "API", value = "kobo")),
    column(2, actionButton("listDatasets", "List Available Datasets"))),
  hr(),
  conditionalPanel(
    condition = "input.listDatasets == 0",
    fluidRow(
      column(6, 
        h3("Usage"),
        p("Enter your", em("username"), ", ", em("password"), ", ", 
          "and the ", em("API"), " that you want to use and click",
          code("List Available Datasets"), ". This will load a 
          table of the IDs and titles of the datasets available, as well 
          as a drop-down select menu with which you can select the 
          dataset that you want to load."),
        p("To view a list of publicly available datasets, use ", 
          code("NULL"), " for both the username and password fields. 
          It may briefly display an error while the dataset is 
          downloading."),
        h3("API"),
        p("API URLs are made available for KoBo Toolbox (", 
          code('"kobo"'), "),", 
          a(href = "https://kc.kobotoolbox.org/api/v1/",
            "https://kc.kobotoolbox.org/api/v1/"), 
          ", KoBo Humanitarian Response (", 
          code('"kobohr"'), "),",
          a(href = "https://kc.humanitarianresponse.info/api/v1/", 
            "https://kc.humanitarianresponse.info/api/v1/"),
          ", and Ona (", 
          code('"ona"'), "),",
          a(href = "https://ona.io/api/v1/", 
            "https://ona.io/api/v1/"),
          ". For your own installation, or other installations using 
          the same API but accessed at a different URL, enter the", 
          em("full URL.")))
      )
    ),
  conditionalPanel(
    condition = "input.listDatasets != 0",
    fluidRow(
      ## `uiOutput` is dynamically created in `server.R`
      column(2, uiOutput("select_dataset"), 
             actionButton("loadDataset", "Load Requested Dataset"),
             br(),
             helpText("NOTE: The requested dataset would be downloaded 
                      to your Global Environment. You may save it for 
                      further offline use."),
             helpText("The object would be named in the form of:"),
             helpText("'data_formid'")),
      column(10,
             tabsetPanel(
               tabPanel(
                 "Available Datasets", dataTableOutput("datasetsAvailable")), 
               tabPanel(
                 "Requested Dataset", dataTableOutput("datasetRequested"))
             ))
      )),
  ## This is to fix the alignment of the "listDatasets" button with
  ##   the rest of the login details.
  tags$style(type='text/css', 
             "#listDatasets { width:100%; margin-top: 25px;}")
  )
)