Mutually reactive Shiny Flexdashboard filters

Question

Just trying to recreate the "Only Relevant Values" feature that some of you may know from Tableau filters... but trying to do this in an RShiny flexdashboard.

Basically, I have a table of chocolates and their companies... When I select a company I only want to see the options for the chocolates of that company. (I already know how to do this one way filtering)...

More importantly I also want the company options to react if I was to select a specific chocolate before a company... for their options to reduce accordingly.

Here is my code:

---
title: "reactive test"
output: 
 flexdashboard::flex_dashboard
runtime: shiny
---

```{r}
library(tidyverse)
```



```{r}

candyData <- read.table(
    text = "Brand       Candy
    Nestle      100Grand
    Nestle      Butterfinger
    Nestle      Crunch
    Hershey's   KitKat
    Hershey's   Reeses
    Hershey's   Mounds
    Mars        Snickers
    Mars        Twix
    Mars        M&Ms",
    header = TRUE,
    stringsAsFactors = FALSE)

```


Sidebar {.sidebar}
---

```{r}

radioButtons("brand",
            "brand:",
            choices = c("All", unique(candyData$Brand)),
            selected = "All")


radioButtons("candy_name",
            "candy_name:",
            choices = c("All", unique(candyData$Candy)),
            selected = "All")

```

Very appreciative of any help with this... or even advice on whether it's even possible.

A. Suliman A. Suliman · Accepted Answer · 2019-03-27T07:17:07

Here is one way using shiny::updateRadioButtons. Please note in order to get the full list of brands after I selected a brand, I add an All to candyData.

```{r}

candyData <- read.table(
  text = "Brand       Candy
All All
    Nestle      100Grand
    Nestle      Butterfinger
    Nestle      Crunch
    Hershey's   KitKat
    Hershey's   Reeses
    Hershey's   Mounds
    Mars        Snickers
    Mars        Twix
    Mars        M&Ms
",
  header = TRUE,
  stringsAsFactors = FALSE)

```

```{r}

  radioButtons("brand",
               "brand:",
               #choices = c("All", unique(candyData$Brand)),
               choices = unique(candyData$Brand),
               selected = "All")


  radioButtons("candy_name",
               "candy_name:",
               choices = unique(candyData$Candy),
               #choices = c("All", unique(candyData$Candy)),
               selected = "All")

   observe({
      req(input$brand)
      x <- input$brand
      if(x=='All'){
        cho1 <- candyData %>% pull(Candy) %>% unique()
      } else{
        cho1 <- filter(candyData, Brand==x) %>% pull(Candy)
      }

      # Can also set the label and select items
      updateRadioButtons(session, "candy_name",
        label = paste("Options for", x,":"),
        choices = cho1,
        selected = cho1[1]
      )
    })

  observe({
      req(input$candy_name)
      y <- input$candy_name
      if(y=='All'){
        cho2 <- unique(candyData$Brand) %>% unique()
      } else{
        cho2 <- filter(candyData, Candy==y) %>% pull(Brand) 
        cho2 <- c(cho2,'All')
      }

      # Can also set the label and select items
      updateRadioButtons(session, "brand",
        choices = cho2,
        selected = cho2[1]
      )
    })



 ```

Mutually reactive Shiny Flexdashboard filters

2 Answers