R Shiny : Write looped reactive inputs to textfile - r

Question

I am currently working on a project in which a user, inputs into the app a set of editrules for an uploaded data set. The user inputs the rule through a textbox input in the UI. I planned to create a text file which contains the editrules set by the user.
Now, my problem is creating a code which creates a list or a vector that contains these editrules since I cant think of a way to insert the user's input into the code. Here is what I have done:
textprepGen <- function(x,y,z){
for(i in 1:x){
z[[i]] <- paste(y[1], paste("input",
paste("input",i, sep = "_"), sep = "$"), sep = " ")
}
return(z)
}
The reason it does not work is because the paste function automatically sets the code into character so it does not read the input, input$input_1, input$input_2, ...
Any suggestions?
Here is the UI and the Server:
shinyUI(fluidPage(theme="bootstrap.css",
titlePanel("Edit Rules"),
sidebarPanel(
fileInput('file_upload', 'Upload CSV File',
accept=c('text/csv',
'text/comma-separated-values,text/plain',
'.csv')),
uiOutput("editrulePanel")
),
mainPanel(
h4("Data Summary")
)
)
)
shinyServer(function(input, output, session) {
# Text input list assignment in order for the data to show up in UI
textinpList <-vector("list", 20)
# Textfile preparation for the lines to be written on the textfile
textprepList <- vector(20)
# Function to generate text inputs
## A for loop is used to generate only the columns that are in the data file
textinpGeneration <- function(x,y,z){
for(i in 1:x){
z[[i]] <- list(textInput(paste("text", i, sep = "_"),
label = h5(y[i]),
value = ">= 0"
)
)
}
return(z)
}
textprepGen <- function(x,y,z){
for(i in 1:x){
z[[i]] <- paste(y[1], paste("input",
paste("input",i, sep = "_"), sep = "$"), sep = " ")
}
return(z)
}
# Dynamic UI
output$editrulePanel <- renderUI ({
# Assigns the input of the uploaded data to a variable
inFile <- input$file_upload
# If no file is uploaded, no table will be displayed in the main panel
if (is.null(inFile))
return(NULL)
# Read csv file uploaded
dataFile <- read.csv(inFile$datapath)
# Count the number of columns of the data file and assign to a variable
## This is used to know the number of options
## to show in the editrule panel
dataCol <- as.numeric(ncol(dataFile))
# Read the column names and assign to a variable
datacolName <- colnames(dataFile)
textprepGen(dataCol, datacolName, textprepList)
# Conditional panel for editrules show if a file has been uploaded
conditionalPanel(condition = "is.null(inFile) == FALSE",
h4("Please input edit rule"),
textinpGeneration(dataCol,datacolName,textinpList)
)
})
# Preparation for writing a textfile
editruleFile <- file("editrules.txt")
writeLines(c(textprepList), editruleFile)
close(editruleFile)
})
The result textfile I wanted to achieve:
# numerical rules
RECOV <= 0
PAID >= 0
CASE >= 0
INC >= 0
Only the logical symbols and the number is the user input.

Answer 1

Anyway, thank you so much Eugene Choe. Just got my code working. Also figured it out to write it in the textfile properly.
Here is the final code for the inputs:
for(i in 1:addruleNumber){
textprepList[i+1+dataCol] <- list(paste(
eval(parse(text = paste("input",
paste("lhand",i,sep="_"),
sep = "$"))),
eval(parse(text = paste("input",
paste("logexp",i,sep="_"),
sep = "$"))),
eval(parse(text = paste("input",
paste("rhand",i,sep="_"),
sep = "$"))),
sep = " "))
}
And here is how I fixed the textfile output:
textprepList[1] <- "# numerical rules"
for(i in 1:dataCol){
textprepList[i+1] <- list(paste(datacolName[i],
eval(parse(text = paste("input",
paste("text",i,sep="_"),
sep = "$"))), sep = " "))
}