Get Node and Edge data from visNetwork graph

问题:

I am trying to get the nodes/edges data from my visNetwork graph. I am using the example code, but it is not working. I am trying to do this with Shiny. My goal is to get the nodes and edges data from the network and then display it in a table. I will greatly appreciate any help that I can get. Thanks,

Here is my code:

require(shiny)
require(visNetwork)

server <- function(input, output) {

  output$network_proxy_nodes <- renderVisNetwork({
    nodes <- data.frame(id = 1:3)
    edges <- data.frame(from = c(1,2), to = c(1,3))

    visNetwork(nodes, edges) %>% visNodes(color = "green")
  })


  output$edges_data_from_shiny <- renderPrint({
    if(!is.null(input$network_proxy_get_edges)){
      input$network_proxy_get_edges
    }
  })

  observe({
    input$getEdges
    visNetworkProxy("network_proxy_get") %>%
      visGetEdges()
  })

  output$nodes_data_from_shiny <- renderPrint({
    if(!is.null(input$network_proxy_get_nodes)){
      input$network_proxy_get_nodes
    }
  })

  observe({
    input$getNodes
    visNetworkProxy("network_proxy_get") %>%
      visGetNodes()
  })
}

ui <- fluidPage(
     visNetworkOutput("network_proxy_nodes", height = "100%"),
           verbatimTextOutput("edges_data_from_shiny "),
           verbatimTextOutput("nodes_data_from_shiny"),
           actionButton("getNodes", "Nodes"),
           actionButton("getEdges", "Edges")
  )

shinyApp(ui = ui, server = server)

回答1:

The main problem with the code is that the name of the network output$network_proxy_nodes was not the same everywhere.

This is a working piece of code to get edge information and display it in plain text, and to get node information and display it as a DataTable:

require(shiny)
require(visNetwork)

server <- function(input, output, session) {
  nodes <- data.frame(id = 1:3, 
                      name = c("first", "second", "third"), 
                      extra = c("info1", "info2", "info3"))
  edges <- data.frame(from = c(1,2), to = c(1,3), id= 1:2)

  output$network_proxy <- renderVisNetwork({
    visNetwork(nodes, edges)
  })


  output$nodes_data_from_shiny <- renderDataTable({
    if(!is.null(input$network_proxy_nodes)){
      info <- data.frame(matrix(unlist(input$network_proxy_nodes), ncol = dim(nodes)[1],
                        byrow=T),stringsAsFactors=FALSE)
      colnames(info) <- colnames(nodes)
      info
    }
  })
  output$edges_data_from_shiny <- renderPrint({
    if(!is.null(input$network_proxy_edges)){
      input$network_proxy_edges
    }
  })

  observeEvent(input$getNodes,{
    visNetworkProxy("network_proxy") %>%
      visGetNodes() 
  })

  observeEvent(input$getEdges, {
    visNetworkProxy("network_proxy") %>%
      visGetEdges()
  })
}

ui <- fluidPage(
  visNetworkOutput("network_proxy", height = "400px"),
  verbatimTextOutput("edges_data_from_shiny"),
  dataTableOutput("nodes_data_from_shiny"),
  actionButton("getEdges", "Edges"),
  actionButton("getNodes", "Nodes")
)

shinyApp(ui = ui, server = server)