insertUI_flexdb.Rmd

---
title: "Untitled"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
runtime: shiny    
---

```{r setup, include=FALSE}
library(flexdashboard)
library(shiny)
library(ggplot2)
library(htmltools)

```


Inputs {.sidebar}
----------------------


```{r}
  
  
      selectInput("dataset", "Pick Dataset", choices = c("mtcars", "iris"), selected = "iris")
      # This will hold column dropdowns and "Add plot" button
      uiOutput("column_ui")

```


Column
------------


```{r}
  # pick the dataset
  dataset <- reactive({
    eval(parse(text = input$dataset))
  })
  
  # Let user choose columns, and add plot.
  output$column_ui <- renderUI({
    choices <- c("Choose one" = "", names(dataset()))
    tagList(
      selectInput("xvar", "X variable", choices),
      selectInput("yvar", "Y variable", choices),
      conditionalPanel("input.xvar && input.yvar",
                       actionButton("addplot", "Add plot")
      )
    )
  })
  
  # One of the very few times you'll see me create a non-reactive
  # session-level variable, and mutate it from within an observer
  plot_count <- 0
  
  # Add a plot when addplot is clicked
  observeEvent(input$addplot, {
    plot_count <<- plot_count + 1
    
    id <- paste0("plot", plot_count)
    # Take a static snapshot of xvar/yvar; the renderPlot we're
    # creating here cares only what their values are now, not in
    # the future.
    xvar <- input$xvar
    yvar <- input$yvar
    
    output[[id]] <- renderPlot({
      df <- brushedPoints(dataset(), input$brush, allRows = TRUE)
      
      ggplot(df, aes_string(xvar, yvar, color = "selected_")) +
        geom_point(alpha = 0.6) +
        scale_color_manual(values = c("black", "green")) +
        guides(color = FALSE) +
        xlab(xvar) + ylab(yvar)
    })
    insertUI("#section-column", where = "afterEnd",
             ui = div(class = 'chart-title', id,
               div(class = 'section level3 chart-wrapper chart-wrapper-flex', style = 'flex: 478 478 0px;',
                      plotOutput(id, brush = "brush", width = 275, height = 275)
             ))
    )
  })
  

```