R shiny教程-3：添加小部件到Shiny App

2020-10-01 本文已影响0人 JeremyL

Shiny app的许多功能都是通过一个小的部件进行充实和调控的。

Basic widgets

Shiny 有一套自定义的小工具，都是通过R函数实现。
例如，Shiny提供了一个名为actionButton的函数来创建一个动作按钮，以及一个名为sliderInput的函数来创建一个滑条。

#标准的Shiny小部件

function	widget
`actionButton`	Action Button
`checkboxGroupInput`	A group of check boxes
`checkboxInput`	A single check box
`dateInput`	A calendar to aid date selection
`dateRangeInput`	A pair of calendars for selecting a date range
`fileInput`	A file upload control wizard
`helpText`	Help text that can be added to an input form
`numericInput`	A field to enter numbers
`radioButtons`	A set of radio buttons
`selectInput`	A box with choices to select from
`sliderInput`	A slider bar
`submitButton`	A submit button
`textInput`	A field to enter text

更多信息可以参看 Twitter Bootstrap。

#添加工具

添加工具，就是将这些工具对应的函数添加到in sidebarPanel 或mainPanel。添加工具与添加HTML 内容类似，直接在ui.R中的面板插入就可以了。

每一个工具函数的前两个参数都是一致的：

a name for the widget: 用户看不到这个名称，开发者需要使用它来访问这个小工具的值；一个字符串。
a label: 会展示在你的App页面；可以为空。
举个例子，名称为“action”，标签为“action”:actionButton("action", label = "Action")

library(shiny)

# Define UI ----
ui <- fluidPage(
  titlePanel("Basic widgets"),
  
  fluidRow(
    
    column(3,
           h3("Buttons"),
           actionButton("action", "Action"),
           br(),
           br(), 
           submitButton("Submit")),
    
    column(3,
           h3("Single checkbox"),
           checkboxInput("checkbox", "Choice A", value = TRUE)),
    
    column(3, 
           checkboxGroupInput("checkGroup", 
                              h3("Checkbox group"), 
                              choices = list("Choice 1" = 1, 
                                             "Choice 2" = 2, 
                                             "Choice 3" = 3),
                              selected = 1)),
    
    column(3, 
           dateInput("date", 
                     h3("Date input"), 
                     value = "2014-01-01"))   
  ),
  
  fluidRow(
    
    column(3,
           dateRangeInput("dates", h3("Date range"))),
    
    column(3,
           fileInput("file", h3("File input"))),
    
    column(3, 
           h3("Help text"),
           helpText("Note: help text isn't a true widget,", 
                    "but it provides an easy way to add text to",
                    "accompany other widgets.")),
    
    column(3, 
           numericInput("num", 
                        h3("Numeric input"), 
                        value = 1))   
  ),
  
  fluidRow(
    
    column(3,
           radioButtons("radio", h3("Radio buttons"),
                        choices = list("Choice 1" = 1, "Choice 2" = 2,
                                       "Choice 3" = 3),selected = 1)),
    
    column(3,
           selectInput("select", h3("Select box"), 
                       choices = list("Choice 1" = 1, "Choice 2" = 2,
                                      "Choice 3" = 3), selected = 1)),
    
    column(3, 
           sliderInput("slider1", h3("Sliders"),
                       min = 0, max = 100, value = 50),
           sliderInput("slider2", "",
                       min = 0, max = 100, value = c(25, 75))
    ),
    
    column(3, 
           textInput("text", h3("Text input"), 
                     value = "Enter text..."))   
  )
  
)

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

# Run the app ----
shinyApp(ui = ui, server = server)