Question

在下面的代码中，我有两个反应函数，比如A和B（我想通过一个隔离函数和两个动作按钮来控制），但只有A可以工作。如果我改变了函数的顺序（我的意思是，我先写B然后再写A），那么B是唯一有效的函数。

该程序正在读取和编辑postgreSQL数据库。功能B在表格中插入一个新行。功能A删除同一个表的一行。

    shinyServer(

    function(input, output) {

        pool <- dbPool(
          drv = dbDriver("PostgreSQL", max.con = 100),
          dbname = "postgres",
          host = "localhost",
          user = "postgres",
          password = "123",
          idleTimeout = 36000
        )

        # Show table in the ui #
        output$view <- renderDataTable({

          dbTable<-dbGetQuery(pool, "SELECT * FROM Table")
          dbTable <- select(dbTable, name, lastname)
          names(dbTable)<-c('Name', 'Lastname')
          dbTable

        }) 

        # show droplist in the ui #
        output$selector <- renderUI({

          droplist  <- dbGetQuery(pool, "SELECT name FROM Table")
          selectInput("paria",  "Delete row", droplist$name) 

        }) 

        # Delete Row # Function A #
        output$val1 <- renderText({

          delete <- sprintf(
            "DELETE FROM %s WHERE %s = '%s'",
            "Table",
            "name",
            input$paria
          )

          if (input$action1 == 0)
            return()
          isolate({
            dbGetQuery(pool, delete) 
            print("Deletion Successful")
          })

        }) 

        # Insert row # Function B #
        output$val1 <- renderText({

          query <- sprintf(
            "INSERT INTO %s (%s, %s) VALUES ('%s', '%s')",
            "Table", 
            "name",
            "lastname",
            input$name,
            input$lastname
          )

          if (input$action2 == 0)
            return()
          isolate({
            dbGetQuery(pool, query) 
            print("Update Successful")
          })

        }) 


    })

ui如下：

    shinyUI(pageWithSidebar(

      headerPanel("Little Program"),

      sidebarPanel(
        conditionalPanel(condition="input.conditionedPanels==1",
                         textInput("name", "Name"),
                         textInput("lastname", "Lastname"),
                         actionButton("action", "Save new person"),
                         br(),br(),
                         uiOutput("selector"),
                         actionButton("action2", "Delete existing person")
        ),
        conditionalPanel(condition="input.conditionedPanels==2",
                         helpText("Content Panel 2")
        ) 
      ),
      mainPanel(
        tabsetPanel(
          tabPanel("Table", value=1, verbatimTextOutput("val1"), dataTableOutput('view')), 
          tabPanel("Panel 2", value=2)
          , id = "conditionedPanels"
        )
      )
    ))

非常感谢您的帮助。

Answer 1

output 显示插入和删除更像是副作用。然后你应该使用observeEvent

以下我创建了2个函数insert和delete，并根据observeEvent从actionButton调用它们。

server.R

shinyServer(

function(input, output) {

    pool <- dbPool(
      drv = dbDriver("PostgreSQL", max.con = 100),
      dbname = "postgres",
      host = "localhost",
      user = "postgres",
      password = "123",
      idleTimeout = 36000
    )

    # Show table in the ui #
    output$view <- renderDataTable({

      dbTable<-dbGetQuery(pool, "SELECT * FROM Table")
      dbTable <- select(dbTable, name, lastname)
      names(dbTable)<-c('Name', 'Lastname')
      dbTable

    }) 

    # show droplist in the ui #
    output$selector <- renderUI({

      droplist  <- dbGetQuery(pool, "SELECT name FROM Table")
      selectInput("paria",  "Delete row", droplist$name) 

    }) 

    # Delete function
    delete <- function(paria) {
        queryDelete <- sprintf(
            "DELETE FROM %s WHERE %s = '%s'",
            "Table",
            "name",
            paria
        )
        dbGetQuery(pool, queryDelete) 
        print("Deletion Successful")
    }

    # Insert function
    insert <- function(name, lastname) {
        queryInsert <- sprintf(
            "INSERT INTO %s (%s, %s) VALUES ('%s', '%s')",
            "Table", 
            "name",
            "lastname",
            name,
            lastname
        )
        dbGetQuery(pool, queryInsert) 
        print("Insert Successful")
    }

    # when delete
    observeEvent(input$delete, {
        delete(paria = input$paria)
    })

    # When insert 
    observeEvent(input$insert, {
        insert(name = input$name, lastname = input$lastname)
    })


})

ui.R

shinyUI(pageWithSidebar(

  headerPanel("Little Program"),

  sidebarPanel(
    conditionalPanel(condition="input.conditionedPanels==1",
                     textInput("name", "Name"),
                     textInput("lastname", "Lastname"),
                     actionButton("action", "Save new person"),
                     actionButton("delete", "DELETE !"),
                     actionButton("insert", "INSERT !")
                     br(),br(),
                     uiOutput("selector")
    ),
    conditionalPanel(condition="input.conditionedPanels==2",
                     helpText("Content Panel 2")
    ) 
  ),
  mainPanel(
    tabsetPanel(
      tabPanel("Table"
        ,dataTableOutput('view')
      ), 
      tabPanel("Panel 2", value=2)
      , id = "conditionedPanels"
    )
  )
))

在服务器文件中写入的两个操作按钮，但只有第一个按钮有效吗？

1 个答案: