r - 在 Shiny 中将 DiagrammeR、data.tree 导出为图像 (png)

Question

我正在尝试从 Shiny App 下载图像，该图像由 DiagrammeR 对象生成。

这是代码：

# Load packages
library(shinythemes)
library(DiagrammeR)
library(data.tree)
library(plotly)
library(shiny)

# Load data
data(acme)

# Define UI
ui <- fluidPage(theme = shinytheme("lumen"),
                titlePanel("Paula trying II"),
                sidebarLayout(
                  sidebarPanel(downloadButton(outputId = "dld_diagrama", label = "Download diagram")),
                  mainPanel(
                    grVizOutput("tree_plot", width = "100%", height = "760px")
                  )
                )
)

# Define server function
server <- function(input, output) {

  output$tree_plot <- renderGrViz({

    plot(acme) 

  })  

output$dld_diagrama <- downloadHandler(
    filename = function(){

      paste("diagram", "png", sep = ".")
    },
    content = function(file) {
      plotly::export(tree_plot, file = "diagram.png")
    }

)

}

# Create Shiny object
shinyApp(ui = ui, server = server)

这会下载（有错误）一个.txt，显然是错误的。我正在尝试下载 .png 我也尝试过使用 appshot，但没有成功。

Answer 1

这是使用闪亮的众多解决方案中的一种，您还可以将导出为 png 按钮带回

library(shinythemes)
library(DiagrammeR)
library(data.tree)
library(plotly)
library(shiny)

data(acme)

# Define UI
ui <- fluidPage(theme = shinytheme("lumen"),
                titlePanel("Paula trying II"),
                sidebarLayout(
                  sidebarPanel(downloadButton(outputId = "dld_diagrama", label = "Download diagram")),
                  mainPanel(
                    grVizOutput("tree_plot", width = "100%", height = "760px")
                  )
                )
)

# Define server function
server <- function(input, output) {

  input_plot <- reactive(plot(acme))

  output$tree_plot <- renderGrViz({

    input_plot() 

  })  

  output$dld_diagrama <- downloadHandler(
    filename = function(){

      paste("diagram", "html", sep = ".")
    },
    content = function(file) {
      htmlwidgets::saveWidget(as_widget(input_plot()), file)
    }

  )

}

# Create Shiny object
shinyApp(ui = ui, server = server)

Answer 2

这有效：

# Load packages
library(shinythemes)
library(DiagrammeR)
library(data.tree)
library(plotly)
library(shiny)

# Load data
data(acme)

# Define UI
ui <- fluidPage(theme = shinytheme("lumen"),
                titlePanel("Paula trying II"),
                sidebarLayout(
                  sidebarPanel(downloadButton(outputId = "dld_diagrama", label = "Download diagram")),
                  mainPanel(
                    grVizOutput("tree_plot", width = "100%", height = "760px")
                  )
                )
)

# Define server function
server <- function(input, output) {

input_plot <- reactive(plot(acme))

  output$tree_plot <- renderGrViz({

    plot(acme) 

  })  

output$dld_diagrama <- downloadHandler(
    filename = function(){

      paste("diagram", "png", sep = ".")
    },
    content = function(file) {
       htmlwidgets::saveWidget(as_widget(input_plot()), "www/diagrama.html", selfcontained = FALSE) 
       webshot(url = "diagrama.html", delay = 5, file = file) 
    }

)

}

# Create Shiny object
shinyApp(ui = ui, server = server)