Better way of scaling a dgr_graph within a shiny app

Question

I'm building a shiny app that is supposed to show a bupaR process_map, which is kind of working.

Sadly the process_map()-function returns a dgr_graph-object, which can't be rendered with the DiagrammeR::renderGrViz() or DiagrammeR::renderDiagrammeR() functions. I found a way to convert it to a grViz / htmlwidget-object with render_graph(), but this way the graph is not nicely scaled. This is especially bad since I'm dealing with very long linear graphs.

Here is a MWE:

# server.R
library(DiagrammeR)
library(bupaR)

shinyServer(
  function(input, output) {

    plot <- patients %>%
      process_map(rankdir = "TB",
                  render = FALSE)

    output$diagram <- renderGrViz({
      render_graph(plot)
    })

  }
)

# ui.R
library(DiagrammeR)

shinyUI(fluidPage(
  titlePanel("DiagrammeR + shiny"),
  grVizOutput(outputId = "diagram")
))

Is there a better way of displaying a dgr_graph-object in shiny, that fills out the whole width of the app and not just a post-stamp size in the middle? Ideal would be something adaptive, without the need for a fixed width in pixels.

Answer 1

As it turns out the problem is not the render_graph-function on the Server, but rather the default setting of the renderGrViz-function in the UI. When you set it to grVizOutput(outputId = "diagram", height = "100%") it works just fine.