Is there a way to use the result of last run in the current run in Shiny? - shiny-reactivity

Question

I am using Shiny to build a dynamic dashboard for the user. I used if statement to divide my code into two main parts. There is an input called "New Line" that user needs to enter "Yes" or "No" as the value for this parameter. If user selects "Yes" the first part of the code will be ran and if he selects "No", it means that the first part is ran before and just the second part of the code needs to be ran. In the second part, there are some parameters from the first part. I want for Shiny to save the results and parameters calculate from ("New Line"==Yes) and use it for the next runs("New Line"==No) until the user change the answer for "New Line" to "Yes" again.
I used observeEvent function and an action button in Shiny. But the problem is that the results of ("New Line"==Yes) can not be used for the next runs.
shinyserver(function(input,output)){
observeEvent(input$click,{
if(input$'New Line' == 'Yes'){}
if(input$'New Line' == 'No'){}
})
}
I expect whenever user enters No for the New Line and hits the action button, the code can use the variables that are calculated when the New Line was Yes. But now whenever I set New Line as No and hit the action button , R just runs the second if. I can copy and paste all the lines from first if to tell R to run all of them again but those line takes about 30 minutes and I do not want to repeat them.

Answer 1

You need to serialise your values somewhere.
One example:
shinyserver(function(input,output)){
observeEvent(input$click,{
if(input$'New Line' == 'Yes'){
data <- result_of_some_function()
some_other_things()
write.csv(data, "file.csv") # saving the data somewhere on disk
}
if(input$'New Line' == 'No'){
mypreviousdata = read.csv("file.csv")
something <- somefunction(mypreviousdata)
}
})
}
Other than saving to CSV, you might prefer a database or the user's cookies, or whatever.