Any chance using input$radio button as argument in group_by - shiny

Question

I have tried to use radio button as an argument in group_by. Since I'm new to Shiny with no JS script background so quite being blind in render/output. and how to adapt with normal R-code.
Please show me some useful document/example in applying input to normal R-code
(not as simple as what's shown in shiny- widget gallery)
dat <- read_csv("VN_MAT as of 202001.csv")
datasetInput <- reactive({
switch(input$radio3,
"A" = "PROD_MANUFACTURER, PROD_BRAND, MKT_SDESC",
"B" = "PROD_MANUFACTURER, PROD_LDESC, MKT_SDESC" )
})
dat_brand <- reactive({
dat %>%
data.frame() %>%
group_by(datasetInput()) %>%
summarise(PER_MAT.TY = round(sum(PER_MAT.TY),digit = 2), PER_MAT.YA = round(sum(PER_MAT.YA), digit
=2)) %>%
arrange(MKT_SDESC) %>%
data.frame() %>%
add_count(MKT_SDESC, wt = PER_MAT.TY) %>%
mutate("VALUE_SHARE_TY" = round(PER_MAT.TY/n, digit = 4)) %>%
select(-n) %>%
add_count(MKT_SDESC, wt = PER_MAT.YA) %>%
mutate("VALUE_SHARE_LY" = round(PER_MAT.YA/n, digit = 4)) %>%
select(-n) %>%
mutate("DIFF_SHARE_YA" = round(VALUE_SHARE_TY - VALUE_SHARE_LY, digit = 4)) %>%
mutate("VALUE_GROWTH" = round(PER_MAT.TY/PER_MAT.YA - 1, digit =4))
})

Answer 1

After trial & error, I can figure out the answer as following code
I have overcome it with using if + choice of code
server <- function(input, output, session){
library(shiny)
library(ggplot2)
library(tidyverse)
Principal <- c("a","a","a","a","b","b","b","b","c","c")
Value <- as.numeric(c(4,1,1,3,4,2,2,3,2,1))
g <- c("t1","t1","t1","t1","t1","t2","t2","t2","t2","t2")
b <- as.numeric(c(4,1,1,3,4,2,2,3,2,1))
df <- data.frame(Principal,Value,g,b)
output$plot <- renderPlot({
if(input$radio1 == 1){
df%>%
group_by(g,b) %>%
summarize(total = sum(Value)) %>%
ggplot(aes(x = total, y = b))+
geom_point()
}else{
df%>%
group_by(Principal,b) %>%
summarize(total = sum(Value)) %>%
ggplot(aes(x = total, y = b))+
geom_point()}
})
}
ui <- basicPage(
radioButtons(
inputId = "radio1",
label = "Radio1",
choices = c(1, 2)
),
plotOutput("plot")
)
shinyApp(ui = ui, server = server)