如何调整Shiny应用中tabPanel的绘图逻辑避免代码冗余

核心思路 #

• 无需新增f2函数导致代码冗余，只需要给现有f1函数新增一个模式控制参数，通过参数切换两类图表的差异配置，公共逻辑完全复用

具体修改点 #

• 为f1函数新增graph_type参数，默认值为"graph1"，不影响原有Graph1的调用逻辑
• 针对两类图表的差异点（列命名、切片变量、plot参数、拟合公式、新数据集构造）做动态适配
• 服务端渲染Graph2时，调用f1传入graph_type = "graph2"即可

修改后的完整代码 #

library(shiny)
library(shinythemes)
library(dplyr)
library(tidyverse)
library(lubridate)

Test <- structure(
    list(date1= c("2021-06-28","2021-06-28"),
         date2 = c("2021-07-01","2021-07-01"),
         Category = c("FDE","ABC"),
         Week= c("Friday","Monday"),
         DR1 = c(14,11),
         DR01 = c(14,12), DR02= c(14,12),DR03= c(19,15),
         DR04 = c(15,14),DR05 = c(15,14),
         DR06 = c(12,14)),
    class = "data.frame", row.names = c(NA, -2L))
  

f1 <- function(df1, dmda, CategoryChosse, graph_type = "graph1") {
  
  x<-df1 %>% select(starts_with("DR0"))
  
  x<-cbind(df1, setNames(df1$DR1 - x, paste0(names(x), "_PV")))
  PV<-select(x, date2,Week, Category, DR1, ends_with("PV"))
  
  med<-PV %>%
    group_by(Category,Week) %>%
    summarize(across(ends_with("PV"), median))
  
  SPV<-df1%>%
    inner_join(med, by = c('Category', 'Week')) %>%
    mutate(across(matches("^DR0\\d+$"), ~.x + 
                    get(paste0(cur_column(), '_PV')),
                  .names = '{col}_{col}_PV')) %>%
    select(date1:Category, DR01_DR01_PV:last_col())
  
  SPV<-data.frame(SPV)
  
  mat1 <- df1 %>%
    filter(date2 == dmda, Category == CategoryChosse) %>%
    select(starts_with("DR0")) %>%
    pivot_longer(cols = everything()) %>%
    arrange(desc(row_number())) %>%
    mutate(cs = cumsum(value)) %>%
    filter(cs == 0) %>%
    pull(name)
  
  (dropnames <- paste0(mat1,"_",mat1, "_PV"))

  datas<-SPV %>%
    filter(date2 == ymd(dmda)) %>%
    group_by(Category) %>%
    summarize(across(starts_with("DR0"), sum)) %>%
    pivot_longer(cols= -Category, names_pattern = "DR0(.+)", values_to = "val") %>%
    mutate(name = readr::parse_number(name))
  
  # 动态配置差异参数
  if (graph_type == "graph1") {
    x_col <- "Days"
    y_col <- "Numbers"
    x_lim <- c(0,45)
    y_lim <- c(0,30)
  } else {
    x_col <- "Reserv"
    y_col <- "Weekdays"
    x_lim <- c(0,80)
    y_lim <- c(0,50)
  }
  colnames(datas)[-1]<-c(x_col, y_col)
  max_x_val <- max(datas[[x_col]])
  
  if(as.Date(dmda) < min(as.Date(df1$date1))){
    datas <- datas %>% 
      group_by(Category) %>% 
      slice(1:max_x_val+1) %>%
      ungroup
  }else{
    datas <- datas %>% 
      group_by(Category) %>% 
      slice((as.Date(dmda) - min(as.Date(df1$date1) [
        df1$Category == first(Category)])):max_x_val+1) %>%
      ungroup
  }
  
  # 动态生成绘图公式
  plot_formula <- reformulate(x_col, y_col)
  plot(plot_formula,  xlim= x_lim, ylim= y_lim,
       xaxs='i',data = datas,main = paste0(dmda, "-", CategoryChosse))
  
  # 动态生成拟合公式
  fit_formula <- as.formula(paste0(y_col, " ~ b1*", x_col, "^2+b2"))
  model <- nls(fit_formula,start = list(b1 = 0,b2 = 0),data = datas, algorithm = "port")
  
  new.data <- data.frame(x = with(datas, seq(min(.data[[x_col]]),max(.data[[x_col]]),len = 45)))
  colnames(new.data) <- x_col
  new.data <- rbind(0, new.data)
  lines(new.data[[x_col]],predict(model,newdata = new.data),lwd=2)
  coef_val<-coef(model)[2]
  points(0, coef_val, col="red",pch=19,cex = 2,xpd=TRUE)
}

ui <- fluidPage(
  
  ui <- shiny::navbarPage(theme = shinytheme("flatly"), collapsible = TRUE,
                          br(),
                          
                          tabPanel("",
                                   sidebarLayout(
                                     sidebarPanel(
                                       
                                       uiOutput("date"),
                                       uiOutput("mycode"),
                                     ),
                                     
                                     mainPanel(
                                       tabsetPanel(
                                         tabPanel("Graph1", plotOutput("graph",width = "100%", height = "600")),
                                         tabPanel("Graph2", plotOutput("graph2",width = "100%", height = "600"))
                                         )
                                       )
                                     ))
                          ))


server <- function(input, output,session) {
  
  data <- reactive(Test)
  
  output$date <- renderUI({
    req(data())
    all_dates <- seq(as.Date('2021-01-01'), as.Date('2021-01-15'), by = "day")
    disabled <- as.Date(setdiff(all_dates, as.Date(data()$date2)), origin = "1970-01-01")
    dateInput(input = "date2", 
              label = h4("Data"),
              min = min(data()$date2),
              max = max(data()$date2),
              value = min(data()$date2))
  })

  output$mycode <- renderUI({
    req(input$date2)
    df1 <- data()
    df2 <- df1[as.Date(df1$date2) %in% input$date2,]
    selectInput("code", label = h4("Category"),choices=unique(df2$Category))
  })
  
  output$graph <- renderPlot({
    req(input$date2,input$code)
    f1(data(),as.character(input$date2),as.character(input$code), graph_type = "graph1")
  })
  
  output$graph2 <- renderPlot({
    req(input$date2,input$code)
    f1(data(),as.character(input$date2),as.character(input$code), graph_type = "graph2")
  })
  
}

shinyApp(ui = ui, server = server)

内容的提问来源于stack exchange，提问作者Antonio