如何在四开仪表板值框中显示值（使用闪亮服务器计算）

Question

我正在尝试使用 Quarto 构建一个仪表板。最初的目标是在 Shiny 服务器上调用仪表板时计算数据集中的案例数量（稍后使用 API 检索）。在“服务器”上下文中，我使用 output$n 渲染 n 计数 <- renderText(nrow(data), and then attempt to retrieve it in a valuebox with textOutput("n"). However, I only see code in the boxes, not the count. What am I doing wrong? (I've tried several variations):

  ---
  title: "Count N"
  format: dashboard
  server: shiny
  ---

  ```{r}
  #| context: setup

  data <- tibble::tibble(a = c(1, 2, 3)) # The data should always be retrieved from a server when the dashboard starts later, that's why I need the server context

  ```

  ## Row 

  ```{r}
  #| content: valuebox
  #| title: "n1"

  # renderText() with paste0

  list(
    value = textOutput("n1")
  )
  ```

  ```{r}
  #| content: valuebox
  #| title: "n2"

  # renderText() without paste0

  list(
    value = textOutput("n2")
  )
  ```

  ```{r}
  #| content: valuebox
  #| title: "n3"

  # it works with a blank (but boring) number

  list(
    value = 99
  )
  ```


  ```{r}
  #| context: server

  n <- data |> nrow() |> as.character()

  output$n1 <- renderText(n)

  output$n2 <- renderText(paste0(n))
  ```

我的输出如下所示：

Answer 1

如here所述，您可以使用

value_box

包中的

bslib

来创建动态值框。确保创建一个像这样的

reactive

值：

---
title: "Count N"
format: dashboard
server: shiny
---

```{r}
#| context: setup
library(shiny)
data <- tibble::tibble(a = c(1, 2, 3)) # The data should always be retrieved from a server when the dashboard starts later, that's why I need the server context

```

## Row 

```{r}
library(bslib)
library(bsicons)
value_box(
  id = "card1",
  title = "n1",
  value = textOutput("n1")
)
```

```{r}
#| content: valuebox
#| title: "n3"

# it works with a blank (but boring) number

list(
    value = 99
)
```


```{r}
#| context: server

n <- reactive({
  data |> nrow() |> as.character()
})
output$n1 <- renderText({n()})
```

输出：