Dynamically choose inputs based on reactive subset data in shiny - r

Question

Setup: I already have build a shiny-app with two plots. I used the flexdashboard-package to create two plots in two tabs. In addition I programmed the whole shiny-app in R-markdown.
Now I want to create an interface where the user can subset the data. That part itself works. However I also need to perform some calculations with the subsetted data, before I do my two plots.
Is there any way I can transform some subsetted object like mydata to a dataframe? My problem is that I need to use this subsetted object also in the UI part of the other plots.
EDIT: I specifically need some way to transport my selection from checkboxGroupInput to selectInput("cat_1"," category 1:",choices = levels(mydata()$mycat).
### 1. Create some sample data
myrows<-sample(letters,12)
exdata<- data.frame(mycat=rep(myrows,2),yr=rep(1:2,each=12),KPI_1=rnorm(24),
KPI_2=round(runif(24,1,20)),KPI_3=rbinom(24,6,0.5))
### 2. UI part
fluidPage(fluidRow(
checkboxGroupInput("comp", "Categories",myrows,myrows,inline=TRUE),
actionButton("go", "Update"),
textOutput("txt"),
tableOutput("head"))
)
### 3. Server part
mydata<-eventReactive(input$go,{
res<-subset(exdata,mycat%in%input$comp)
return(res)
})
output$txt <- renderText({
paste("You chose", paste(input$comp, collapse = ", "))
})
output$head <- renderTable({
mydata()
})
In the next chunk I do this:
library(plotly)
library(shiny)
### 4. UI part of my plot
fluidRow(sidebarLayout(sidebarPanel(
selectInput("cat_1",
" category 1:",
choices = levels(mydata()$mycat),
selected = levels(mydata()$mycat)[1]),
selectInput("cat_2",
" category 2:",
choices = levels(mydata()$mycat),
selected = levels(mydata()$mycat)[2])),
mainPanel(plotlyOutput("plot3", height = 300, width = 700))))
### 5. Server part of my plot
output$plot3 <- renderPlotly({
## 5.1 Create plot data
cat1<-input$cat_1
cat2<-input$cat_2
y1<-as.numeric(mydata()[mydata()$mycat==cat1])
y2<-as.numeric(mydata()[mydata()$mycat==cat2])
x0<-c(1,2)
## 5.2 Do plot
plot_ly(x = x0,y = y1, type="scatter",mode='lines+markers',name=Firm1) %>%
add_trace(y = y2, name = Firm2, mode = 'lines+markers') %>%
layout(dragmode = "select")

Answer 1

It took me a while to figure out your code. So:
1) Make use of renderUI which will allow you to dynamically create controls
2) Stick with one ui
3) Make sure you understand the renderPlotly and what you're trying to plot
library(shiny)
library(plotly)
### 1. Create some sample data
myrows<-sample(letters,12)
exdata<- data.frame(mycat=rep(myrows,2),yr=rep(1:2,each=12),KPI_1=rnorm(24),
KPI_2=round(runif(24,1,20)),KPI_3=rbinom(24,6,0.5))
ui <- fluidPage(
sidebarPanel(
uiOutput("c1"),uiOutput("c2")),
mainPanel(
column(6,
checkboxGroupInput("comp", "Categories",myrows,myrows,inline=TRUE),
actionButton("go", "Update"),
textOutput("txt"),
tableOutput("head")),
column(6,
plotlyOutput("plot3", height = 300, width = 700)))
)
server <- function(input, output) {
### 3. Server part
mydata <- eventReactive(input$go,{
res<-subset(exdata,mycat%in%input$comp)
return(res)
})
output$txt <- renderText({
paste("You chose", paste(input$comp, collapse = ", "))
})
output$head <- renderTable({
mydata()
})
conrolsdata <- reactive({
unique(as.character(mydata()$mycat))
})
output$c1 <- renderUI({
selectInput("cat_1", "Variable:",conrolsdata())
})
output$c2 <- renderUI({
selectInput("cat_2", "Variable:",conrolsdata())
})
output$plot3 <- renderPlotly({
if(is.null(input$cat_1)){
return()
}
y1<- mydata()$KPI_1[as.character(mydata()$mycat) %in% input$cat_1]
y2<- mydata()$KPI_2[as.character(mydata()$mycat) %in% input$cat_2]
x0<-c(1,2)
#use the key aesthetic/argument to help uniquely identify selected observations
plot_ly(x = x0,y = y1, type="scatter",mode='lines+markers',name="Firm1") %>%
add_trace(y = y2, name = "Firm2", mode = 'lines+markers') %>%
layout(dragmode = "select")
})
}
shinyApp(ui, server)