lapply with 2 vectors? A Shiny example

0
votes

I'm sorry if this is a little redundant with posts pertaining to lapply with multiple arguments but I'm still struggling to apply those concepts within my nested functions. I also appoligize if the title doesn't quite get to the crux of my question and am open to suggestions!

I'd like to create a series of lists in Shiny from a series of data frames, where each list is given a title corresponding to the name of the data frame:

Desired Output

test

  • A
  • B
  • C

test2

  • D
  • E
  • F

test3

  • G
  • H
  • I

I first created all_tests, a list containing all the dataframes, with names corresponding to the dataframes.

I want to use this within a series of functions:

  • rowBlock creates the li element (A, B, C, D, E, F) etc
  • rowPallete creates the ul element of all the rowBlocks for each dataframe, along with the title of the dataframe
  • rowArea combines all the rowPalletes given the user specified list of dataframes (all_tests). This is the function I'd like to use within App.R
library(shiny)

# This is a repex where really I'm going to be importing x # of data frames
# I want to use their column names within each list
# And title each list the name of the dataframe
test <- data.frame("A" = NA, "B" = NA, "C" = NA)
test2 <- data.frame("D" = NA, "E" = NA, "F" = NA)
test3 <- data.frame("G" = NA, "H" = NA, "I" = NA)

all_tests <- list(colnames(test), colnames(test2), colnames(test3))
names(all_tests) <- c("test", "test2", "test3")

# each column name should be a li
rowBlock <- function(name) {
  tags$li(
    class = "block", id = name,
    div(name)
  )
}

# each dataframe should be its own list
# and titled with the name of the df
rowPallete <- function(data) {
  div(
    lapply(names(data), h5),
    tags$ul(
      class="all_blocks",
      lapply(data, rowBlock)
    ))
}

# combine the different dataframes into a series of lists
# to be used within app.R
rowArea <- function(bins) {
  column(1, offset = 0, style='padding:0px;',
         lapply(bins, rowPallete)
  )
}

I can get the code to work when I don't include ul titles, but I'm struggling to apply two vectors to the same lapply function. I've been playing around with using column names, names(all_tests) but seem to still be missing something. Any help appreciated!

1
rlapply
Map is the multiple-input equivalent of lapply. Example: Map(paste, 1:10, 11:20) (yes the example is dumb since paste is vectorized already, but it illustrates the way Map works) - IceCreamToucan
Would you mind helping me a little more concretely as this applies to the RowPallete function? I'm using lapply twice in the same function on the same vector, but it's not working when trying to generate the titles for each list (h5) - MayaGans

1 Answers

1
votes

This seems to be what you're after (rowBlock is unchanged)

# each dataframe should be its own list
# and titled with the name of the df
rowPallete <- function(data) {
  Map(function(x, y) 
        div(h5(x), tags$ul(class = 'all_blocks', lapply(colnames(y), rowBlock))),
      names(data),
      data)
}

rowArea <- function(bins) {
  column(1, offset = 0, style='padding:0px;',
         rowPallete(bins)
  )
}

ui <- rowArea(all_tests)
server <- function(input, output) {
}

shinyApp(ui = ui, server = server)