如何在闪亮的服务器功能中复制无功值 [英] how to make a copy of a reactive value in shiny server function
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问题描述
I am building a Shiny app and using the code from this question as an example: How to download editable data table in shiny. However, in my code the df <- reactiveVal(dat)
does not work, because the dat
itself is already a reactive value that comes from an eventReactive({})
function. This is the code I am working with, it works if I define the dat
outside of the server, but not when it is created inside the server function of shiny. How do I make a copy of it so that I can show it in a new table (and potentially process further and download in later steps in the app)?
library(shiny)
library(DT)
library(shinyWidgets)
# if the data frame is just an object, it works
#dat <- iris[1:3, ]
ui <- fluidPage( actionBttn(
inputId = "btnProcess",
label = "Process",
size = "sm",
color = "success"
),
DTOutput("my_table"),
DTOutput("table2")
)
server <- function(input, output){
# if the dataframe is a reactive variable, this doesnt work.
dat <- eventReactive(input$btnProcess, {
iris[1:3, ]
})
output[["my_table"]] <- renderDT({
datatable(dat(), editable = "cell")
})
#############################
#### none of these work #####
#############################
#df <- reactiveVal(dat)
#df <- reactiveVal(dat())
#df <- dat()
#df <- dat
observeEvent(input[["my_table_cell_edit"]], {
cell <- input[["my_table_cell_edit"]]
newdf <- df()
newdf[cell$row, cell$col] <- cell$value
df(newdf)
})
output[["table2"]] <- renderDT({
datatable(df())
})
}
shinyApp(ui, server)
推荐答案
尝试一下
ui <- fluidPage( actionBttn(
inputId = "btnProcess",
label = "Process",
size = "sm",
color = "success"
),
actionBttn(inputId = "reset", label = "Reset", size="sm", color="warning"),
DTOutput("mytable"),
DTOutput("table2")
)
server <- function(input, output){
# if the dataframe is a reactive variable, this doesnt work.
dat <- eventReactive(input$btnProcess, {
iris[1:3, ]
})
mydf <- reactiveValues(data=NULL)
observe({
mydf$data <- dat()
})
output$mytable <- renderDT({
datatable(mydf$data, editable = "cell")
})
observeEvent(input$mytable_cell_edit, {
info = input$mytable_cell_edit
str(info)
i = info$row
j = info$col
v = info$value
mydf$data[i, j] <<- DT::coerceValue(v, mydf$data[i, j])
})
output[["table2"]] <- renderDT({
datatable(mydf$data)
})
observeEvent(input$reset, {
mydf$data <- dat() ## reset it to original data
})
}
shinyApp(ui, server)
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