如何基于四级层级树形输入实现DataFrame的四级代码筛选

需求：使用包含四级层级（All product -> category -> HS2 -> HS4 -> HS6）的树形输入对DataTable进行筛选，选中任意父级节点时，DataTable始终基于第四级HS4代码进行筛选。

实现思路 #

1. 捕获树形组件选中节点的完整路径
2. 解析路径前缀，匹配数据中所有属于该前缀下的HS4代码
3. 用HS4代码集合筛选DataTable数据

修改后的完整代码 #

library(shiny)
library(jsTreeR)
library(DT)

ui <- fluidPage(
  dropdownButton(
    inputId = "mydropdown",
    label = "Select products",
    icon = "",
    status = "primary",
    circle = FALSE,
    jstreeOutput("mytree")
  ),
  
  DTOutput("table")
  
)

server <- function(input, output, session) {
  
  df <- data.frame(
    all = c("All product","All product","All product","All product","All product","All product","All product","All product",
            "All product","All product","All product","All product","All product","All product","All product","All product"),
    category = c("Agriculture","Agriculture","Agriculture","Agriculture", "Agriculture","Agriculture","Agriculture","Agriculture",
                 "Non Agriculture", "Non Agriculture", "Non Agriculture", "Non Agriculture","Non Agriculture", "Non Agriculture", "Non Agriculture", "Non Agriculture"),
    HS2 = c("01","01","01","01","02","02","02","02","03","03","03","03","04","04","04","04"),
    HS4 = c("0101","0101","0102","0102","0201","0201","0202","0202","0301","0301","0302","0302","0401","0401","0402","0402"),
    HS6 = c("010101","010102", "010201","010202","020101","020102","020201","020202","030101","030102", "030201","030202","040101","040102","040201","040202")
  )
  
  output$mytree <- renderJstree({
    
    makeNodes <- function(leaves){
      dfs <- lapply(strsplit(leaves, "/"), function(s){
        item <- 
          Reduce(function(a,b) paste0(a,"/",b), s[-1], s[1], accumulate = TRUE)
        data.frame(
          item = item,
          parent = c("root", item[-length(item)]),
          stringsAsFactors = FALSE
        )
      })
      dat <- dfs[[1]]
      for(i in 2:length(dfs)){
        dat <- merge(dat, dfs[[i]], all = TRUE)
      }
      f <- function(parent){
        i <- match(parent, dat$item)
        item <- dat$item[i]
        children <- dat$item[dat$parent==item]
        label <- tail(strsplit(item, "/")[[1]], 1)
        if(length(children)){
          list(
            text = label,
            children = lapply(children, f),
            icon =FALSE,
            state = list(selected = TRUE, opened = FALSE )
          )
        }else{
          list(text = label, type = "child",icon = FALSE,
               state = list(selected = TRUE,opened = FALSE ))
        }
      }
      lapply(dat$item[dat$parent == "root"], f)
    }
    
    # 转换为路径向量
    paths <- apply(df, 1, function(x) paste0(x, collapse = "/"))
    
    # 生成节点列表
    nodes <- makeNodes(paths)
    
    jstree(
      nodes,
      checkboxes = TRUE,
      theme = "proton",
      checkCallback = JS("$.jstree.defaults.core.expand_selected_onload = false;"),
      plugins = c("checkbox")
    )
    
  })
  
  # 处理选中节点，提取对应的HS4代码
  selected_HS4 <- reactive({
    req(input$mytree_get_selected)
    selected_paths <- input$mytree_get_selected
    
    # 解析每个选中路径，提取前缀，匹配对应的HS4
    hs4_list <- lapply(selected_paths, function(path) {
      path_parts <- strsplit(path, "/")[[1]]
      # 根据路径长度判断层级，生成匹配条件
      if(length(path_parts) == 1){ # 选中All product
        unique(df$HS4)
      } else if(length(path_parts) == 2){ # 选中category
        unique(df$HS4[df$category == path_parts[2]])
      } else if(length(path_parts) == 3){ # 选中HS2
        unique(df$HS4[df$HS2 == path_parts[3]])
      } else if(length(path_parts) == 4){ # 选中HS4
        path_parts[4]
      } else { # 选中HS6，取对应的HS4
        unique(df$HS4[df$HS6 == path_parts[5]])
      }
    })
    
    # 去重合并所有HS4
    unique(unlist(hs4_list))
  })
  
  output$table <- renderDT({
    datatable(df[df$HS4 %in% selected_HS4(), ])
  })
  
}

shinyApp(ui, server)

关键说明 #

• selected_HS4 反应式变量：负责解析选中节点的路径，根据不同层级提取对应的HS4代码集合。比如选中"Agriculture"时，会返回该分类下所有的HS4代码；选中HS2的"01"时，返回该HS2下的HS4代码。
• 树形组件配置：保留checkbox插件，确保选中父节点时子节点自动选中，同时通过input$mytree_get_selected获取完整选中路径。
• DataTable筛选：直接根据提取的HS4集合过滤数据，确保始终基于第四级HS4进行筛选。

内容的提问来源于stack exchange，提问作者akshay bholee