r shiny add element dynamically to reactive value - r

Question

I'm trying to learn how to use shiny modules to simplify a messy shiny app I have. The app currently reads in several data sets using a list of names like this:
dataSetsToLoad <- c("set1name", "set2name", "etc")
for (i in 1:length(dataSetsToLoad) {
dt <- readRDS(paste0(dataSetsToLoad[i], ".RDS")
assign(dataSetsToLoad[i], dt)
}
These end up in the global environment and are accessible to all my non-modularized code.
Following a code pattern from here, I'd like to modify the above to something like the following
stash = reactiveValues()
for (i in 1:length(dataSetsToLoad) {
stashVar <- paste0("stash$", dataSetsToLoad[i])
dt <- readRDS(paste0(dataSetsToLoad[i], ".RDS")
assign(stashVar, dt)
}
The summary question is how do I put the dt into the stash reactive with the dynamically created name in stashVar. A second question is whether there is any way to test this without actually running it in a shiny app.

Answer 1

You can do something like this. Store the dataframes in a list and then assign them in a loop to the reactiveValues().
dflist <- list(mtcars, airquality, mtcars)
library(shiny)
# Define UI for application that draws a histogram
ui <- fluidPage(
# Application title
titlePanel("Old Faithful Geyser Data"),
# Sidebar with a slider input for number of bins
sidebarLayout(
sidebarPanel(
sliderInput("bins",
"Number of bins:",
min = 1,
max = 3,
value = 3)
),
# Show a plot of the generated distribution
mainPanel(
plotOutput("distPlot")
)
)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
values <- reactiveValues()
for(i in 1:length(dflist)) {
values[[paste0("df_", i)]] <- dflist[[i]]
}
observeEvent(input$bins, {
print(values$df_1)
print(values$df_2)
print(values$df_3)
})
}
# Run the application
shinyApp(ui = ui, server = server)