Using observer to hold the resulted data subset in a vector - r

Question

I am new to Shiny R.Can anyone help me solve the issue below.
I am trying to plot the data using a dataset, and with a user defined option "All" added to the "selectlist" of "region" provided in UI.
When "All" option is selected from "selectlist", how can I use the below observer to store information about all the regions into vector "l", so that the same can be used to query based on other user inputs
observe({
if("All" %in% input$region) {
selected <- setdiff(allchoice, "All")
updateSelectInput(session, "region", selected = selected)
}
})
Ref: How to add a user defined value to the select list of values from dataset
UI.R
library(shiny)
library("RMySQL")
library(ggplot2)
library(plotly)
library(DT)
library(dplyr)
dataset <- read.csv("dataset.csv", header=TRUE)
dataset$X <- NULL
allchoice <- c("All", levels(dataset$region))
fluidPage(
title = "ABC XYZ",
hr(),
fluidRow(
titlePanel("ABC XYZ"),
sidebarPanel(
dateRangeInput('dateRange',
label = 'Date Input',
start = as.Date("1967-01-01"), end = Sys.Date()),
selectInput("region", label = "Region",
choices = allchoice,
selected = 1),
selectInput("gender", label = "Gender",
choices = unique(dataset$gender), multiple = TRUE,
selected = unique(dataset$gender)),
selectInput('x', 'X', names(dataset), names(dataset)[[2]]),
selectInput('y', 'Y', names(dataset), names(dataset)[[8]]),
hr()
),
mainPanel(
column(12, plotlyOutput("plot1")),
hr(),
column(12, plotlyOutput("plot2"))
)
)
)
Server.r
library(ggplot2)
library("RMySQL")
library("mgcv")
library(plotly)
function(input, output, session) {
dataset <- read.csv("dataset.csv", header=TRUE)
dataset$X <- NULL
dataset$date <- as.Date(dataset$date)
if(input$region == "All"){
l <- observe({
if("All" %in% input$region) {
selected <- setdiff(allchoice, "All")
updateSelectInput(session, "region", selected = selected)
}
})
}
else{
l <- reactive(subset(dataset, region %in% input$region))
}
k <- reactive({subset(l(), date >= as.Date(input$dateRange[1]) & date <= as.Date(input$dateRange[2]))})
n <- reactive(subset(k(), gender %in% input$gender))
#output plots
output$plot1 <- renderPlotly({
p <- ggplot(n(), aes_string(x=input$x, y=input$y)) + geom_point(alpha=0.4)
ggplotly(p)
})
output$plot2 <- renderPlotly({
q <- ggplot(n(), aes_string(x=input$x, y=input$y)) + geom_smooth()
ggplotly(q)
})
}
Error I am facing -
Warning: Error in .getReactiveEnvironment()$currentContext: Operation not allowed without an active reactive context. (You tried to do something that can only be done from inside a reactive expression or observer.)
Stack trace (innermost first):
46: .getReactiveEnvironment()$currentContext
45: .subset2(x, "impl")$get
44: $.reactivevalues
43: $ [D:\Demo\server.R#36]
42: server $ [D:\Demo\server.R#36]
1: runApp
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.)
Note: My vocabulary above may be off, so please correct me if I'm wrong, I am totally new to the world of R.
Thanks in advance.
EDIT 1:
Listening on http://127.0.0.1:5128
We recommend that you use the dev version of ggplot2 with `ggplotly()`
Install it with: `devtools::install_github('hadley/ggplot2')`
Warning in origRenderFunc() :
Ignoring explicitly provided widget ID "2988253b22c1"; Shiny doesn't use them
We recommend that you use the dev version of ggplot2 with `ggplotly()`
Install it with: `devtools::install_github('hadley/ggplot2')`
`geom_smooth()` using method = 'gam'
Warning in origRenderFunc() : Ignoring explicitly provided widget ID "29885be33e8"; Shiny doesn't use them
and even when i do that, I am getting many exceptions and sometimes the same exceptions as above again. Just worried if the same will affect the application in the long run, can you suggest anything about that?
Thanks again.

Answer 1

You have not provided an example data so i can only guess and via looking at your error which says clearly whats the problem: no active reactive context, i assume that it is exactly in this part:
if(input$region == "All"){
l <- observe({
if("All" %in% input$region) {
selected <- setdiff(allchoice, "All")
updateSelectInput(session, "region", selected = selected)
}
})
}
else{
l <- reactive(subset(dataset, region %in% input$region))
}
[!] but actually i do not understand what for you need the observer...i think it should work totally fine if you just use if...else... statement.
[!] And additionally i have no idea why at first you say you wanna get the vector of choices (except "All") and you use it as selected choice in selectInput, may i ask what for?
and else statement should give you subset of the data based on input$region.
So shortly saying: if gives you updatedSelectInput and else gives you dataset --> It actually does not make sense at all..
and should be as simple as that, if "All" is selected then there is no need to subset the dataset, if any other choice then "All" is selected then the subset of the dataset should happen:
l <- reactive({
if(input$region == "All"){
dataset
}else{
dataset <- subset(dataset, region %in% input$region)
}})