Access data created from reactive function to define reactiveValues in Shiny - r

Question

I'm exploring the possibilities with interactive ggplot2 in shiny. Inspired by this I created a shiny app that exclude points from a dataset and plots the data where the excluded points are of a different color.
app.R
library(shiny)
library(ggplot2)
server<-function(input, output) {
data <- reactive({
set.seed(10)
df=data.frame(x=rnorm(100),y=rnorm(100))
df
})
vals<-reactiveValues(keeprows=rep(TRUE, 100))
output$plot1 <- renderPlot({
df=data()
keep=df[vals$keeprows, ,drop=FALSE]
exclude=df[!vals$keeprows, ,drop=FALSE]
plot=ggplot(data=keep,aes(x,y))+geom_point()+theme_bw()+
geom_point(data=exclude,fill=NA,col="black",alpha=0.75,shape=21)
plot
})
observeEvent(input$plot1_click,{
df=data()
res <- nearPoints(df, input$plot1_click, allRows = TRUE,threshold=5)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
}
ui <- fluidPage(
titlePanel("Reactive test"),
mainPanel(
plotOutput("plot1",click="plot1_click")
)
)
shinyApp(ui = ui, server = server)
This works perfectly, but now I want to be able to define vals with:
vals<-reactiveValues(keeprows=rep(TRUE,nrow(CustomDataInput))
In the case of my example, I tried accessing number of rows from the data created in data():
vals<-reactiveValues(keeprows=rep(TRUE,nrow(data()))
This gives me an error because I tried to access a reactive variable in a non-reactive environment. Is there a way to access the data created in a reactive function to define reactiveValues?
Thank you for your time!

Answer 1

The error pretty much addresses the problem. The correct way to do this is as follows.
library(shiny)
library(ggplot2)
server<-function(input, output) {
vals <- reactiveValues()
data <- reactive({
set.seed(10)
df=data.frame(x=rnorm(100),y=rnorm(100))
vals$keeprows = rep(TRUE,nrow(df))
df
})
#vals<-reactiveValues(keeprows=rep(TRUE,100))
output$plot1 <- renderPlot({
df=data()
keep=df[vals$keeprows, ,drop=FALSE]
exclude=df[!vals$keeprows, ,drop=FALSE]
plot=ggplot(data=keep,aes(x,y))+geom_point()+theme_bw()+
geom_point(data=exclude,fill=NA,col="black",alpha=0.75,shape=21)
plot
})
observeEvent(input$plot1_click,{
df=data()
res <- nearPoints(df, input$plot1_click, allRows = TRUE,threshold=5)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
}
ui <- fluidPage(
titlePanel("Reactive test"),
mainPanel(
plotOutput("plot1",click="plot1_click")
)
)
shinyApp(ui = ui, server = server)
Declare the vals variable before hand and use that in reactive() function to send variables to vals as shown above. You should be fine.