---
title: "My Google Sheets Explorer"
output: github_document
---

```{r}
library(googlesheets)
```

## Description

This app is currently deployed [here](https://jennybc.shinyapps.io/20_gs-explorer). 

**My Google Sheets Explorer** allows any user to log in using their Google account. After authorization, the user is presented with a listing of all their Google Sheets. The user is allowed to select a Sheet of interest and additional details about the Sheet will be presented in the `Sheet Info` tab. The user is also allowed to quickly inspect the worksheets that live in the selected Sheet by going to the `Sheet Inspection` tab. Simply select a worksheet and a visual representation of the worksheet is displayed.

---

## Running app locally 

`googlesheets` currently has set up web application credentials in Google Developer Console. If you are creating an app locally, default app credentials are built into `googlesheets`, __but remember to run your app using `runApp(port = 4642)`__. Credentials are accessible through:

```{r}
getOption("googlesheets.webapp.client_id")
getOption("googlesheets.webapp.client_secret")
getOption("googlesheets.webapp.redirect_uri")
```

Two functions are used to get authorization working: `gs_webapp_auth_url()` and `gs_webapp_get_token()`.

The general flow is:

1. User clicks a button that will take them to the URL formed by `gs_webapp_auth_url`.  

```{r}
# looks like this
gs_webapp_auth_url()
```

2. User authenticates is redirected back to app. An authorization code also gets returned in the url, which it can be extracted using `parseQueryString(session$clientData$url_search)$code`. 

3. Use `gs_webapp_get_token()` to extract the authorization code, make a POST request to exchange for an access token, and put the token in the internal `googlesheets` environment for use in subsequent API requests.

## Setting up authorization in your own app

You must create your own web application in [Google Developer's Console](https://console.developers.google.com/). Obtain the client ID, client secret and set the redirect URI to some static local url ie. `http://127.0.0.1:4642` (for testing so every time you would run `runApp(port = 4642)` ). Depending on where you will deploy your app, you will later come back and add that destination as another redirect uri. 

After setting up the web application, in your `server.R` set client ID and secret, and redirect uri specific to your project by:

```
options("googlesheets.webapp.client_id" = MY_CLIENT_ID)
options("googlesheets.webapp.client_secret" = MY_CLIENT_SECRET)
options("googlesheets.webapp.redirect_uri" = MY_REDIRECT_URI)
```
