Interactivity with shiny, Part II

class: center, middle

### More `shiny`

### Kelly McConville

.large[Math 241 | Week 11 | Spring 2021]

---

## Announcements/Reminders

* Don't forget [to sign-up for your final project group](https://docs.google.com/spreadsheets/d/1lA4KYLbkxBBA57OoiuZgOL2cnYdTvb1JR7lzxy5xKUA/edit#gid=0).

* Lab 8 due in two weeks.
    + Don't submit on Gradescope.
    + Upload to your Math 241 repo and put on either the Reed Shiny Server or [https://www.shinyapps.io/](https://www.shinyapps.io/).
    + Can work with another Math 241 student.

---

## Goals

* Recap `shiny`
* Uploading to the Reed Shiny Server
* Updating `leaflet` maps
* Displaying the code in your app
* Modifying the layout and adding HTML components
* More practice

---

### But First:  [Another Take on Spatial Data](https://www.nytimes.com/interactive/2021/04/06/us/variants-cases-spread.html)

---

### [Isostat Lucy McGowan for the win!](https://livefreeordichotomize.com/2021/04/07/nytimes-map-how-to/)

```r
library(tidycensus)
library(tidyverse)
library(geofacet)
library(zoo)
```

```r
api_key <- "insert your key"
```

```r
pop <- get_acs(geography = "state", variables = "B01003_001",
               year = 2019, key = api_key,
               cache_table = TRUE)
cases <- read_csv("https://github.com/nytimes/covid-19-data/raw/master/us-states.csv")
```

---

```r
d <- cases %>%
  group_by(state) %>%
  mutate(case = c(cases[1], diff(cases))) %>%
  ungroup() %>%
  filter(!(date == as.Date("2021-03-08") &
             state == "Missouri")) %>% 
  left_join(pop, by = c("fips" = "GEOID")) %>%
  group_by(state) %>%
  arrange(date) %>%
  mutate(
    case_7 = rollmean(case, k = 7, fill = NA),
    case_per_100 = (case_7 / estimate) * 100000) %>%
  ungroup() %>%
  filter(date > as.Date("2021-01-31"),
         date < as.Date("2021-04-05"))

states <- tibble(state = state.name,
                 state_ = state.abb) %>%
   add_row(state = "District of Columbia", state_ = "DC")

d <- left_join(d, states, by = "state") %>%
  filter(!is.na(state_))

d <- d %>% 
  group_by(state) %>%
  slice_min(case_per_100) %>%
  slice(1) %>%
  mutate(min_date = date) %>%
  select(min_date, state) %>%
  left_join(d, by = "state") %>%
  mutate(col = ifelse(date >= min_date, "yes", "no"))
```

---

```r
ggplot(d, aes(x = date, y = case_per_100)) + 
  geom_line(color = "#BE2D22") + 
  geom_area(aes(fill = col), alpha = 0.75) +
  scale_fill_manual(values = c("white", "#BE2D22")) +
  facet_geo(~state_) + 
  theme_minimal() +
  labs(x = "", y = "",
       title = "Cases per 100,000",
       subtitle = "Feb 1 - Apr 4, Red area indicates rise since lowest point of 2021",
       caption = "Note: Shows seven-day average") +
  theme(axis.text = element_blank(),
        axis.ticks = element_blank(),
        panel.grid.minor = element_blank(),
        panel.grid.major.x = element_blank(),
        legend.position = "none")
```

---

### The Key: [`facetgeo`](https://cran.r-project.org/web/packages/geofacet/vignettes/geofacet.html)

---

## `shiny` Recap -- Main Components

* **Inputs**: What user manipulates
    + Text
    + Sliders
    + Dropdown menus
    + Action buttons

* **Output**: What changes based on user's selections
    + Graphs
    + Maps
    + Tables
    + Text

* Use **reactive programming**
    + Update outputs when inputs change
    
---

## `shiny` Recap -- Main Components

* **UI**: User interface
    + Defines how your app **looks**

* **Server function**
    + Defines how your app **works**

```r
library(shiny)

# User interface
ui <- fluidPage()

# Server function
server <- function(input, output){}

# Creates app
shinyApp(ui = ui, server = server)
```

---

## Let's Practice.

* Grab the "appPractice.Rmd" file in the `ShinyApps` folder in our shared folder on the RStudio Server.

* I am going to put you in Breakout Rooms.
    + If you have any questions, try to help each other but also use the "Ask For Help" feature and Simon or I will hop in.

* If you finish before we come back together, start dressing up your app, adding more interactivity, or helping the others in your Breakout Room.

* Then we will come back together and go through the answers.

---

## More Reactivity: `observe()`

* Let's look at another app in the shared folder.
    + Within the ShinyApps folder, it is in "app_biketown".

* Features `leaflet` functions and `observe()`.

* Need to use `leafletProxy()` so that the entire map isn't redrawn with each update to the inputs.

---

## Uploading to Shiny Server

* [Let's go through the process together](https://www.reed.edu/data-at-reed/resources/R/archive/shiny-server.html).

---

## Including your code on your app

```r
runApp("/home/mcconville/ShinyApps/math241_names/app.r", 
       display.mode = "showcase")
```

---

## So Much More:

* Consider using a [different theme](https://rstudio.github.io/shinythemes/) than the default theme:

```r
library(shinythemes)
```

```r
ui <-  fluidPage(theme = shinytheme("superhero"),
  ...
)
```

* [Add HTML Elements](https://shiny.rstudio.com/articles/tag-glossary.html) 
    + Let's look at the app in the "app_HTML" folder.

* [Layout Options](https://shiny.rstudio.com/articles/layout-guide.html)
    + Let's look at the app in the "app_tabs" folder.

---

## Dashboards

* Dashboards are a way to make your `shiny` web application even shinier

* Examples:
    + [GREGORY](https://shiny.reed.edu/s/users/wojciko/stats_greg/)
    + [Fires](https://shiny.reed.edu/s/users/aflowers/fires/)
    
--

* Two `R` Packages:
    + [`flexdashboard`](https://rmarkdown.rstudio.com/flexdashboard/)
    + [`shinydashboard`](https://rstudio.github.io/shinydashboard/)