add an app that reads/writes a private sheet

how did we not have one of these already?

[skip ci]

Author: jennybc

.gitignore

@@ -10,3 +10,4 @@ README.html
 pics
 jenny_token.rds
 rsconnect
+shiny_app_token.rds

inst/shiny-examples/10_read-write-private-sheet/server.R

@@ -0,0 +1,21 @@
+library(shiny)
+library(googlesheets)
+
+shinyServer(function(input, output, session) {
+
+  observeEvent(
+    input$reset,
+    gs_edit_cells(ss, input = filler)
+  )
+  observeEvent(
+    input$submit,
+    gs_edit_cells(ss, input = input$contents,
+                  ## the +1 business is to avoid writing into the header row
+                  anchor = cell_limits(c(input$row + 1, input$column),
+                                       c(input$row + 1, input$column)))
+  )
+  the_data <- eventReactive({input$submit | input$reset},
+                            gs_read(ss), ignoreNULL = FALSE)
+  output$table <- renderTable(the_data())
+
+})

inst/shiny-examples/10_read-write-private-sheet/ui.R

@@ -0,0 +1,31 @@
+library(shiny)
+library(shinythemes)
+
+shinyUI(
+  fluidPage(
+    theme = shinytheme("cosmo"),
+    titlePanel("Read and write a private Google Sheet"),
+    sidebarLayout(
+      sidebarPanel(
+        h6(paste("This app is hard-wired to target a private Google Sheet.")),
+        h6(paste("You can't visit the Sheet in the browser, because it's",
+                 "private. Which is the whole point of this example.")),
+        h6("Fail to browse the Sheet: ",
+           a("HERE", href = ss$browser_url, target="_blank")),
+        h6(a("Click Here to See Code on Github",
+             href="https://github.com/jennybc/googlesheets/tree/master/inst/shiny-examples/10_read-write-private-sheet",
+             target="_blank")),
+        sliderInput("row", "Row", min = 1, max = n, value = 1, step = 1,
+                    ticks = FALSE),
+        selectInput("column", "Column",
+                    choices = setNames(seq_len(n), colnames(filler))),
+        selectInput("contents", "Cell contents",
+                    choices = c("apple", "grape", "banana")),
+        actionButton("submit", "Submit", class = "btn-primary"),
+        actionButton("reset", "Reset", class = "btn-primary")
+      ),
+      mainPanel(
+        tableOutput("table")
+      )
+    )
+  ))

inst/shiny-examples/README.md

@@ -26,12 +26,11 @@ We've built a few simple apps to get you started in some important use cases:
     - [03_craigslist-lost-and-found](03_craigslist-lost-and-found): reads from a public spreadsheet that utilizes the Google Sheet function `IMPORTXML` to read data from Vancouver's Craigslist's Lost and Found listings. See it deployed [here](https://jennybc.shinyapps.io/03_craigslist-lost-and-found).
     - [04_embedded-google-form](04_embedded-google-form): a Google Form is embedded in the app, allowing user to enter data with native Google Form/Sheets functionality. App also displays the underlying Sheet, allowing user to see the just-entered data. See it deployed [here](https://jennybc.shinyapps.io/04_embedded-google-form).
   * Credentials are baked into the app:
-    - *make one of these!*
+    - [10_read-write-private-sheet](10_read-write-private-sheet): app users are allowed to view and edit data in a private Google Sheet via the app. A token stored in a file within the app is used for auth. See it deployed [here](https://jennybc.shinyapps.io/10_read-write-private-sheet).
+    - See [Persistent data storage in Shiny apps](http://deanattali.com/blog/shiny-persistent-data-storage), a blog post by [Dean Attali](http://deanattali.com), for another example of using a Google Sheet as a Shiny data store. He shows how to append new rows to a data table. His app loads the token from the cache in a `.httr-oauth` file.
   * User provides Google credentials via the app:
     - [20_gs-explorer](20_gs-explorer): app requires the user to authenticate with Google and authorize the app to deal on their behalf. After authorization, the user is presented with a listing of their Sheets, the option to view details of each spreadsheet and inspect the worksheets contained in a spreadsheet.
 
-Dean Attali also includes a Google Sheets + `googlesheets` example in his blog post [Persistent data storage in Shiny apps](http://deanattali.com). *not published yet but will be soon*
-
 ## More inspiration for feeding Google Sheets:
 
 Here are examples of using Google Sheets as an online datastore from Amit Argawal's [blog](http://www.labnol.org/tag/guide/):