shiny using selectizeInput to build dynamic data output

Question

The inputs are displayed in "iris$Petal.Width - iris$Species" format.Upon selected inputs, data to be split and iris$Petal.Width alone to be used to filter entire data. Example: selected values are as in the image.

Try to get data like dplyr::filter(iris,iris$Petal.Width %in% c('0.2','0.3','0.1','0.6','1.4')) How to form the c('0.2','0.3','0.1','0.6','1.4') dynamically.

Taken this example for easy understanding, actually the inputs are in A001 - Description1, A002 - Description2 format. Need to take A001, A002 to form c('A001','A002').

Tried with below code:

## run in interactive R sessions
if (interactive()) {

  ui <- fluidPage(

    selectizeInput('ipdesc', label='Selector', 
                   choices = as.list(c(unique(paste(iris$Petal.Width,iris$Species,sep = " - ")))),
                   multiple = TRUE,
                   options = list(maxItems = 5)
    ),
    p("Select Codes (Max 5), then press 'Go'"),
    actionButton("go", label = "Go"),
    tableOutput("selected")
  )

  server <- function(input, output) {
    #
    output$selected <- renderTable({
      filterdata()
    })

    filterdata <- eventReactive(input$go,{
      x=c()
      cnt = length(input$ipdesc)
      for (i in 1:cnt){
        if (i != cnt) {
          x[i] = cat(sapply(strsplit(input$ipdesc[i], " - "), "[", 1),",")
        }
        else
        {x[i] = cat(x[1],sapply(strsplit(input$ipdesc[i], " - "), "[", 1))}

      } })


    #

  }

  shinyApp(ui, server)

}

score 0 · Answer 1 · answered Jan 13 '17 at 14:47

This isn't really a shinyapps or shinyjs question, all you need to know is how to match split a string to match part of it to a data frame. Because you're working with data frames, strsplit() may not be the most elegant solution.

As you mention dplyr, I will give you a tidyverse option:

Try using separate() from the tidyr package. convert = TRUE means that the resulting columns should be automatically converted to numeric/integer/logical if possible.

library(dplyr)
library(tidyr)

input <- "1.8 - versicolor"

temp <- data.frame(input = input) %>%
          tidyr::separate(input, c("Petal.Width", "Species"), 
                          sep = " - ", convert = TRUE)
filtered <- dplyr::filter(iris, iris$Petal.Width %in% temp$Petal.Width)

filtered output:

#    Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
# 1           5.9         3.2          4.8         1.8 versicolor
# 2           6.3         2.9          5.6         1.8  virginica
# 3           7.3         2.9          6.3         1.8  virginica
# 4           6.7         2.5          5.8         1.8  virginica
# 5           6.5         3.0          5.5         1.8  virginica
# ...

Note that this matches both versicolor and virginica.

Combined with your shiny script:

library(shiny)
if (interactive()) {

  ui <- fluidPage(
    selectizeInput('ipdesc', label='Selector', 
                   choices = as.list(c(unique(paste(iris$Petal.Width,iris$Species,sep = " - ")))),
                   multiple = TRUE,
                   options = list(maxItems = 5)
    ),
    p("Select Codes (Max 5), then press 'Go'"),
    actionButton("go", label = "Go"),
    tableOutput("selected")
  )

  server <- function(input, output) {

    output$selected <- renderTable({
      filterdata()
    })

    filterdata <- eventReactive(input$go, {
      temp <- data.frame(input = input$ipdesc) %>%
        tidyr::separate(input, c("Petal.Width", "Species"), sep = " - ", convert = TRUE)

       iris %>%
         dplyr::filter(iris$Petal.Width %in% temp$Petal.Width)

    })    
  }

  shinyApp(ui, server)

}

Thanks Steffi LaZerte, your approach comes very close to solving my problem. The inputs are in "A00 - Description" format. Hence when I run it gives error message as "Error: operations are possible only for numeric, logical or complex types". Any suggestion please. — SPS, Jan 16 '17 at 10:38
You will want to omit the `convert = TRUE` argument. That argument tells `separate()` to convert the result to numeric (in the above case). But in your case, you will end up with 'A00' and 'Description', neither of which are numeric (nor logical nor complex), which I suspect is why you are receiving this error. — Steffi LaZerte, Jan 16 '17 at 13:47

shiny using selectizeInput to build dynamic data output

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