Error in reactive environment in Shiny Plot - r

Question

This is my first question, so please be patient with me. I am trying to pass a dataset into an interactive shiny plot. Here is the gist of what I have on the server side.
# Load all necessary packages
load <- c(
"shiny",
"shinythemes",
"ggplot2",
"BH",
"DT",
"rCharts",
"markdown",
"data.table",
"dplyr"
)
loaded <- lapply(load, function(x) {
if (!require(x, character.only = T)) {
install.packages(x)
require(x, character.only = T)
}
})
# Define UI for application that draws a histogram
ui <- navbarPage(
"Testkit",
# Tabpanel for Upload and Overview ----
tabPanel(
"Upload & Overview",
# Sidebar layout with input and output definitions ----
sidebarLayout(
# Sidebar panel for inputs ----
sidebarPanel(
# Input: Select a file ----
fileInput(
"file1",
"Choose CSV File",
multiple = TRUE,
accept = c("text/csv",
"text/comma-separated-values,text/plain",
".csv")
),
# Horizontal line ----
tags$hr(),
# Input: Checkbox if file has header ----
checkboxInput("header", "Header", TRUE),
# Input: Select separator ----
radioButtons(
"sep",
"Separator",
choices = c(
Comma = ",",
Semicolon = ";",
Tab = "\t"
),
selected = ","
),
# Input: Select quotes ----
radioButtons(
"quote",
"Quote",
choices = c(
None = "",
"Double Quote" = '"',
"Single Quote" = "'"
),
selected = '"'
),
# Horizontal line ----
tags$hr(),
# Input: Select number of rows to display ----
radioButtons(
"disp",
"Display",
choices = c(Head = "head",
All = "all"),
selected = "head"
),
# Horizontal line ----
tags$hr(),
# Input: First Variable ----
selectizeInput(
'e1',
'1. Select First Variables',
choices = NULL,
multiple = FALSE
),
# Horizontal line ----
tags$hr(),
# Input: Second Variable ----
selectizeInput(
'e2',
'2. Select Seconed Variables',
choices = NULL,
multiple = FALSE
)
),
# end of sidebarPanel
# Main panel for displaying outputs ----
mainPanel(
# Tabset panels for displaying outputs
tabsetPanel(
tabPanel(p(icon("area-chart"), "Single Graph"),
fluidPage(fluidRow(
column(
width = 12,
plotOutput(
"sPlot",
height = 700,
click = "sPlot_click",
brush = brushOpts(id = "sPlot_brush")
),
actionButton("exclude_toggle", "Toggle points"),
actionButton("exclude_reset", "Reset")
)
)))
# end of Single Graph tab) # end of tabPanel ) # end of mainPanel)))
# Define server logic required to draw a histogram
server <-
function(input, output, session) {
# Function for file upload ----
my_data <- reactive({
# input$file1 will be NULL initially. After the user selects
# and uploads a file, head of that data file by default,
# or all rows if selected, will be shown.
req(input$file1)
df <- read.csv(
input$file1$datapath,
header = input$header,
sep = input$sep,
quote = input$quote
)
if (input$disp == "head") {
return(head(df))
}
else {
return(df)
}
})
# Pass list of variables to selectize ----
observe(updateSelectizeInput(session, 'e1', choices = colnames(select(
my_data(), contains("Var_")
))))
observe(updateSelectizeInput(session, 'e2', choices = colnames(select(
my_data(), contains("Var_")
))))
# Function for sectioning table ----
sliceData <- reactive({
sData <- my_data() %>%
select(one_of(c(input$e1, input$e2)))
return(sData)
})
# Create output for interactive plot tab ----
vals <-
reactiveValues(keeprows = rep(TRUE, nrow(sliceData())))
IA_Plot <- reactive({
# Plot the kept and excluded points as two separate data sets
keep <-
sliceData()[vals$keeprows, , drop = FALSE]
exclude <-
sliceData()[!vals$keeprows, , drop = FALSE]
IAP <-
ggplot(keep, aes(input$e1, input$e1)) + geom_point() +
geom_smooth(method = lm,
fullrange = TRUE,
color = "black") +
geom_point(
data = exclude,
shape = 21,
fill = NA,
color = "black",
alpha = 0.25
) +
coord_cartesian(xlim = c(1.5, 5.5), ylim = c(5, 35))
IAP
})
# Create single graph plot for interaction ----
output$sPlot <- renderPlot({
IA_Plot()
})
# Toggle points that are clicked ----
observeEvent(input$sPlot_click, {
res <- nearPoints(sliceData(), input$sPlot_click, allRows = TRUE)
vals$keeprows <-
xor(vals$keeprows, res$selected_)
})
# Toggle points that are brushed, when button is clicked ----
observeEvent(input$exclude_toggle, {
res <- brushedPoints(sliceData(), input$sPlot_brush, allRows = TRUE)
vals$keeprows <-
xor(vals$keeprows, res$selected_)
})
# Reset all points ----
observeEvent(input$exclude_reset, {
vals$keeprows <- rep(TRUE, nrow(sliceData()))
})
}
# Run the application
shinyApp(ui = ui, server = server
)
Here is the error I got from R Studio:
Warning: Error in .getReactiveEnvironment()$currentContext: Operation not allowed without an active reactive context. (You tried to do something that can only be done from inside a reactive expression or observer.)
Could someone help me with what I am missing?
Thanks!!

Answer 1

The error you are getting is from vals <- reactiveValues(keeprows = rep(TRUE, nrow(sliceData()))). You can read the reactive expressions only inside observe
Try putting that statement inside observe, something like this:
observe({
vals <-reactiveValues(keeprows = rep(TRUE, nrow(sliceData())))
})
Hope it helps!