当使用plotlyproxy

Question

我正在努力使下面的代码正常工作。

我记得您可以强制使用plotlyproxy和plotlyProxyInvoke relayout来放大图，并且在某种程度上，我的测试应用程序确实会调整范围，但是由于某种原因，它会重置立即达到全范围，我无法弄清楚如何避免这种情况，或者到底是什么原因造成的。

library(shiny)
library(plotly)



ui <- fluidPage(
           plotlyOutput('PlotPlot'),
           br(),
             checkboxInput(inputId = 'AddAnnot', label = 'trigger rerender', value = F)
    )


server <- function(input, output, session) {

  values <- reactiveValues()

  output$PlotPlot <- renderPlotly({
    ypar <- 'mpg'
    xpar <- 'cyl'

    p <- plot_ly(source = 'PlotMTCARS', 
                 data = mtcars,
                 height = 450,
                 width =  750) %>%
      add_trace(x = mtcars[[xpar]],
                y = mtcars[[ypar]],
                type = 'scatter',
                mode = 'markers') %>%
      layout(
        title = "Plot with zoom",
        margin = list(l = 20, r= 220, b = 20, t = 50),
        showlegend = FALSE,
        xaxis =  list(title = xpar),
        yaxis =  list(title = ypar)
      )

    ## add annotation to simulate changes that cause a rerender of any kind
    if(input$AddAnnot){
      p <- add_annotations(p,
                           x = 1.4,
                           y = 0.70,
                           xref = "paper", yref = "paper", align = 'right',
                           textangle = 0, 
                           font = list(size = 14,
                                       color = '#c0c0c0'),
                           text =  'Just text',
                           showarrow = F
      )
    }

    #this code updates the zoom, but somehow it gets overruled again by something
    isolate({
      if(!is.null(values$PlotZoomXmin)) {
        print('applying')
        print(paste("setting zoom:", values$PlotZoomYmin))
        plotlyProxy('PlotPlot', session) %>%
            plotlyProxyInvoke("relayout", list(yaxis = list(title = 'mpg', 
                                                            showgrid = F, 
                                                            range = list(values$PlotZoomYmin,values$PlotZoomYmax)
                                                            ),
                                               xaxis = list(title = 'cyl', 
                                                            showgrid = F, 
                                                            range = list(values$PlotZoomXmin,values$PlotZoomXmax)
                                                            )
                                               )
                              )

        Sys.sleep(2)
      }
    })


    p

  })




  relayout_zoom <- reactive({
    zoom <- event_data("plotly_relayout", source = "PlotMTCARS")
    zoom 
  })


  observe({
    zoom <- relayout_zoom()
    if(!is.null(zoom$`xaxis.range[0]`)) {
      values$PlotZoomXmin <- zoom$`xaxis.range[0]`
      values$PlotZoomXmax <- zoom$`xaxis.range[1]`
      values$PlotZoomYmin <- zoom$`yaxis.range[0]`
      values$PlotZoomYmax <- zoom$`yaxis.range[1]`
    }
  })

}

shinyApp(ui, server)