Preserve row order of rhandsontable in shiny app - r

Question

I am running an example from here.
library(rhandsontable)
library(shiny)
runApp(shinyApp(
ui = fluidPage(rHandsontableOutput("hot")),
server = function(input, output, session) {
fname <- "mtcars2.csv"
values <- reactiveValues()
setHot <- function(x) values[["hot"]] = x
observe({
if(!is.null(values[["hot"]])) write.csv(values[["hot"]], fname)
})
output$hot <- renderRHandsontable({
if (!is.null(input$hot)) {
DF <- hot_to_r(input$hot)
} else {
DF <- read.csv("mtcars.csv", stringsAsFactors = FALSE)
}
setHot(DF)
rhandsontable(DF) %>%
hot_table(highlightCol = TRUE, highlightRow = TRUE) %>%
hot_cols(columnSorting = TRUE)
})
}
))
I want changes made to table be saved in file mtcars2.csv. I also want to preserve row order. In project home page it says "sorting only impacts the widget and will not reorder the original data set". Can I somehow get current view of a table and save it?

Answer 1

The best way to answer this question will be to file an issue at https://github.com/jrowen/rhandsontable. Currently, these lines define only a partial list of handsontable events. This list does not include afterColumnSort which would be what you need. Here is a quick hack to partially answer your question.
library(rhandsontable)
library(shiny)
library(htmlwidgets)
runApp(shinyApp(
ui = fluidPage(
rHandsontableOutput("hot"),
tags$script(
'
setTimeout(
function() {
HTMLWidgets.find("#hot").hot.addHook(
"afterColumnSort",
function(){
console.log("sort",this);
Shiny.onInputChange(
"hot_sort",
{
data: this.getData()
}
)
}
)
},
1000
)
'
)
),
server = function(input, output, session) {
observeEvent(
input$hot_sort
,{
print(input$hot_sort$data)
}
)
output$hot <- renderRHandsontable({
if (!is.null(input$hot)) {
DF <- hot_to_r(input$hot)
} else {
DF <- mtcars
}
rhandsontable(DF) %>%
hot_table(highlightCol = TRUE, highlightRow = TRUE) %>%
hot_cols(columnSorting = TRUE)
})
}
))

Answer 2

I don't think there is a way to preserve the sorted columns in DataTables for shiny, Sad!
With the below code I'm able to save changes made in shiny app to the file mtcars2.csv. Interestingly! post sorting by desired column, clicking on any data cell and pressing enter key saves the row order to the mtcars2.csv. Agree with timelyportolio's point on filing an issue on git.
R Code:
library(shiny)
library(rhandsontable)
runApp(shinyApp(
ui = fluidPage(titlePanel("Edit Data File"),
helpText("Changes to the table will be automatically saved to the source file."),
# actionButton("saveBtn", "Save"),
rHandsontableOutput("hot")),
shinyServer(function(input, output, session) {
values = reactiveValues()
data = reactive({
if (is.null(input$hot)) {
hot = read.csv("mtcars.csv", stringsAsFactors = FALSE)
} else {
hot = hot_to_r(input$hot)
}
# this would be used as a function input
values[["hot"]] = hot
hot
})
observe({
# input$saveBtn
if (!is.null(values[["hot"]])) {
write.csv(values[["hot"]], "mtcars.csv", row.names = FALSE)
}
})
output$hot <- renderRHandsontable({
hot = data()
if (!is.null(hot)) {
hot = rhandsontable(hot) %>%
hot_table(highlightCol = TRUE, highlightRow = TRUE) %>%
hot_cols(columnSorting = TRUE)
hot
}
})
})
))