创建反应式 selectInput - 带有 Shiny 的 flexdashboard [英] Create reactive selectInput - flexdashboard with Shiny

问题描述

我正在尝试在 flexdashboard 文档中使用 Shiny 进行响应式 selectInput.

I'm trying to make a reactive selectInput using Shiny in a flexdashboard document.

1. 我的第一个 selectInput 选择海洋公园的区域类型.

1. My first selectInput selects the type of Zone in a Marine Park.

selectInput("Zone", label = "Marine Park Zoning:",
          choices = c("All", levels(EoTR$MarineParkZone)), selected = "All")

然后我使用此输入创建一个反应数据框，其中仅包含在步骤 1 中选择的区域.

Then I use this input to create a reactive data frame with only the Zones selected in step 1.

zone.choices = reactive({
  if (input$Zone=="All"){
  select(EoTR, ReefName, MarineParkZone, MarineParkMgmtSection)
  }else{
  select(EoTR, ReefName, MarineParkZone, MarineParkMgmtSection)%>%
  filter(MarineParkZone==input$Zone)}
})

然后我尝试使用这个反应数据框来定义我对下一个 selectInput

reactive({
selectInput("Reef", label = "Priority Reef:",
        choices = zone.choices()$ReefName, selected = "Arlington Reef (16-064)")
})

当我运行文档时，我的第二个输入显示了一堆代码而不是选择菜单，因此基于该选择器的所有进程都失败了.

When I run the document my second input displays a bunch of code instead of the select menu and therefore all the processes based from that selector fail.

下面是一些可以重现问题的代码

Below is some code that will reproduce the problem

---
title: "Untitled"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
runtime: shiny 
---
```{r}
library(flexdashboard)
library(dplyr)

EoTR = data.frame(ReefName=c("Reef1", "Reef2", "Reef3", "Reef4"), 
              MarineParkZone=c("Fished", "Fished", "Un-Fished", "Un-Fished"))

selectInput("Zone", label = "Marine Park Zoning:",
          choices = c("All", levels(EoTR$MarineParkZone)), selected = "All")

zone.choices = reactive({
  if (input$Zone=="All"){
  select(EoTR, ReefName, MarineParkZone)
  }else{
  select(EoTR, ReefName, MarineParkZone)%>%
  filter(MarineParkZone==input$Zone)}
})

reactive({
selectInput("Reef", label = "Priority Reef:",
        choices = zone.choices()$ReefName, selected = "Reef1")
})
```

我知道我定义响应式输入的方式可能有些愚蠢，但我非常感谢您对此的任何帮助.

I know it's probably something silly with how I'm defining my reactive input but I'd really appreciate any help on this.

干杯，

山姆

推荐答案

这是适合您的解决方案:

Here is the solution for you:

---
title: "Untitled"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
runtime: shiny 
---
```{r}
library(flexdashboard)
library(dplyr)

EoTR = data.frame(ReefName=c("Reef1", "Reef2", "Reef3", "Reef4"), 
              MarineParkZone=c("Fished", "Fished", "Un-Fished", "Un-Fished"))

selectInput("Zone", label = "Marine Park Zoning:",
          choices = c("All", levels(EoTR$MarineParkZone)), selected = "All")

zone.choices = reactive({
  if (input$Zone=="All"){
  EoTR
  }else{
  EoTR %>%
  filter(MarineParkZone==input$Zone)}
})


renderUI({selectInput("Reef", label = "Priority Reef:",
        choices = zone.choices()$ReefName, selected = "Reef1")})

```

问题在于您的 selectInput("Reef"...)，您已将其设置为响应式(这是不正确的)-->您应该宁愿将其渲染为 UI 对象 (renderUI).

The problem was with your selectInput("Reef"...), you have set it to be reactive (which is inccorect) --> you should rather render it as UI object (renderUI).

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