shiny.Rmd

# Interactive apps with `shiny`

We will need

```{r, message = FALSE}
library("shiny")
```

## The architecture of a `shiny` app

The overview figure below is based and makes reference to
[*the written tutorial*](http://shiny.rstudio.com/tutorial/lesson1/).

![shiny app overview](./figs/shiny-overview.jpg)

### Running the apps

```{r, eval = FALSE}
## in ui.R
shinyUI(fluidPage(...))
```

```{r, eval = FALSE}
## in server.R
shinyServer(function(input, ouput) {
    ...
})
```

```{r, eval = FALSE}
runApp("app-dir")
```

### Example apps

* [`shiny-app1`](./shiny-app1)

![shiny-app1](./figs/app1.png)

* [`shiny-app2`](./shiny-app1)

![shiny-app2](./figs/app2.png)

### Single-file app

```{r, eval = FALSE}
ui <- fluidPage(...)
server <- function(input, output) { ... }

app <- list(ui = ui, server = server)
runApp(app)
```

### Sharing

* Share the code file(s) and `runApp`
* `runUrl`
* `runGitHub`
* `runGist`
* [shinyapps](http://wwwshinyapps.io)
* Shiny server

### Exercise

Read and understand the code of the apps above and run them
locally. Then, try to update them to replace of add some widgets.

### More interactivity

```{r, eval = FALSE}
 plotOutput("pca",
            hover = "hover",
            click = "click",
            dblclick = "dblClick",
            brush = brushOpts(
                id = "brush",
                resetOnNew = TRUE))
```

Example [here](http://shiny.rstudio.com/gallery/plot-interaction-advanced.html).

## Shiny apps

Push your shiny apps online with [shinyapps](http://www.shinyapps.io/).


## References

* [`shiny` page](http://shiny.rstudio.com/)
* [`shiny` cheat sheet](https://www.rstudio.com/wp-content/uploads/2016/01/shiny-cheatsheet.pdf)