bborgesr

# -------------------------------------------------------------------
# ------------------ PROCESSING DATA MODULARLY----------------------
# -------------------------------------------------------------------

# This app processes some input text through three modules, passing 
# the result of each module down to the next module. We're also 
# displaying to the user the (reactive) result of each module, but
# usually we'd just be interested in the last one... In those cases,
# the modules' ui functions would be empty (except for the last 
# module, of course).

bborgesr

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      tags$a("Go to Panel 1", href = "#panel1"), br(),
      tags$a("Go to Panel 2", href = "#panel2"), br(),
      tags$a("Go to Panel 3", href = "#panel3")
    ),
    mainPanel(

bborgesr

library(shiny)
library(shinyjs) 

ui <- fluidPage(
  useShinyjs(),
  fileInput('inFile', 'Choose file'),
  actionButton('reset', 'Reset'),
  tableOutput('tbl')
)

bborgesr

library(shiny)
library(shinydashboard)

ui <- dashboardPage(
  dashboardHeader(title = "Dropdowns 2.0",
    dropdownMenuOutput("menu")
  ),
  dashboardSidebar(
    helpText("Add another item to the dropdown menu by clicking ",
             "on the button below"),

bborgesr

GROKKING NOTES

I liked the way Grokking the coding interview organized problems into learnable patterns. However, the course is expensive and the majority of the time the problems are copy-pasted from leetcode. As the explanations on leetcode are usually just as good, the course really boils down to being a glorified curated list of leetcode problems.

So below I made a list of leetcode problems that are as close to grokking problems as possible.

Pattern: Sliding Window

• https://leetcode.com/problems/maximum-subarray/ # Close enough
• https://leetcode.com/problems/minimum-size-subarray-sum/

bborgesr

library(shiny)

reactiveTrigger <- function() {
  counter <- reactiveVal( 0)
  list(
    depend = function() {
      counter()
      invisible()
    },
    trigger = function() {

bborgesr

library(shiny)
ui <- fluidPage(
  textInput("divID", "Enter an ID for the custom area:", ""),
  helpText("Leave the text input blank for automatically unique IDs."),
  actionButton("isrt", "Add a datatable"), 
  tags$div(id = "placeholder")
)

server <- function(input, output, session) {
  rv <- reactiveValues()

bborgesr

# -------------------------------------------------------------------
# ------------------ REACTIVES INSIDE FOR LOOPS ---------------------
# -------------------------------------------------------------------

# -------------------------------------------------------------------
# --- EXAMPLE 1: this works fine, because there are no reactives in -
# --- the for lopp --------------------------------------------------
# -------------------------------------------------------------------
library(shiny)