R Shiny 验证列号输入文件
R Shiny validate column number input file
我正在复制闪亮文件上传应用程序的示例。如您所见,我为文件类型添加了一个验证函数。我还设置了固定的列名,因为我想让用户最多只能上传5列的日期。
现在,当用户上传的文件的列数超过允许的数量时,将显示一条 R 消息:
more columns than column names
.
我想要一个 validate/require 函数来检查列数并显示更加用户友好的消息。我的想法是将验证函数与 (ncol(input$file1)<=5)==TRUE
一起使用,但不知何故这似乎不起作用。有人知道如何检查输入文件的列数并更改显示的用户消息吗? (如果能用 Shinyalert 完成那就太棒了!)。
最后,我也在努力寻找我如何包装 table 我绕过一个我以后可以回忆起的反应性数据框。
提前致谢!
library(shiny)
library(tools)
ui <- fluidPage(
# App title ----
titlePanel("Uploading Files"),
# Sidebar layout with input and output definitions ----
sidebarLayout(
# Sidebar panel for inputs ----
sidebarPanel(
# Input: Select a file ----
fileInput("file1", "Choose CSV File",
multiple = FALSE,
accept = c("text/csv",
"text/comma-separated-values,
text/plain",
".csv")),
# Horizontal line ----
tags$hr(),
# Input: Select separator ----
radioButtons("sep", "Separator",
choices = c(Comma = ",",
Semicolon = ";",
Tab = "\t"),
selected = ","),
# Input: Select quotes ----
radioButtons("quote", "Quote",
choices = c(None = "",
"Double Quote" = '"',
"Single Quote" = "'"),
selected = '"'),
# Horizontal line ----
tags$hr(),
# Input: Select number of rows to display ----
radioButtons("disp", "Display",
choices = c(Head = "head",
All = "all"),
selected = "head")
),
# Main panel for displaying outputs ----
mainPanel(
# Output: Data file ----
tableOutput("contents")
)
)
)
server <- function(input, output) {
output$contents <- renderTable({
# input$file1 will be NULL initially. After the user selects
# and uploads a file, head of that data file by default,
# or all rows if selected, will be shown.
req(input$file1)
# when reading semicolon separated files,
# having a comma separator causes `read.csv` to error
tryCatch(
{
df <- read.csv(input$file1$datapath,
header = F,
sep = input$sep,
quote = input$quote,
col.names = c("COL1","COL2","COL3","COL4","COL5"),
check.names = F)
},
validate(
need(file_ext(input$file1$datapath) %in% c(
'text/csv',
'text/comma-separated-values',
'text/tab-separated-values',
'text/plain',
'csv'
), "Data was not recognized. Please use a CSV file!")),
error = function(e) {
# return a safeError if a parsing error occurs
stop(safeError(e))
}
)
if(input$disp == "head") {
return(head(df))
}
else {
return(df)
}
})
}
shinyApp(ui,server)
我试图构建一个示例程序,用户只能上传只有 5 列的 csv 数据集。您可以根据您的要求进行更改。
UI.R
library(shiny)
library(shinydashboard)
library(shinyjs)
library(shinyalert)
dashboardPage(
dashboardHeader(title = "Basic dashboard"),
dashboardSidebar(
sidebarMenu(
menuItem("Dashboard", tabName = "dashboard", icon = icon("dashboard"))
)
),
dashboardBody(
useShinyalert(),
tabItems(
tabItem(tabName = "dashboard",
fluidRow(
column(3,
fileInput("file1", "Choose CSV File",
multiple = FALSE,
accept = c("text/csv",
"text/comma-separated-values,
text/plain",
".csv"))
)
),
fluidRow(
tableOutput("contents")
)
)
)
)
)
Server.R
library(shiny)
library(shinydashboard)
shinyServer(function(input,output){
output$contents <- renderTable({
inFile <- input$file1
if (is.null(inFile))
{
returnValue()
}
else
{
data<-read.csv(inFile$datapath)
if(ncol(data)<5)
{
shinyalert("Column Error","Uploaded Data has less than 5 Col",type="error")
returnValue()
}
else if(ncol(data)>5)
{
shinyalert("Column Error","Uploaded Data has more than 5 Col",type = "error")
returnValue()
}
else
{
return(data)
}
}
})
})
我正在复制闪亮文件上传应用程序的示例。如您所见,我为文件类型添加了一个验证函数。我还设置了固定的列名,因为我想让用户最多只能上传5列的日期。
现在,当用户上传的文件的列数超过允许的数量时,将显示一条 R 消息:
more columns than column names
.
我想要一个 validate/require 函数来检查列数并显示更加用户友好的消息。我的想法是将验证函数与 (ncol(input$file1)<=5)==TRUE
一起使用,但不知何故这似乎不起作用。有人知道如何检查输入文件的列数并更改显示的用户消息吗? (如果能用 Shinyalert 完成那就太棒了!)。
最后,我也在努力寻找我如何包装 table 我绕过一个我以后可以回忆起的反应性数据框。
提前致谢!
library(shiny)
library(tools)
ui <- fluidPage(
# App title ----
titlePanel("Uploading Files"),
# Sidebar layout with input and output definitions ----
sidebarLayout(
# Sidebar panel for inputs ----
sidebarPanel(
# Input: Select a file ----
fileInput("file1", "Choose CSV File",
multiple = FALSE,
accept = c("text/csv",
"text/comma-separated-values,
text/plain",
".csv")),
# Horizontal line ----
tags$hr(),
# Input: Select separator ----
radioButtons("sep", "Separator",
choices = c(Comma = ",",
Semicolon = ";",
Tab = "\t"),
selected = ","),
# Input: Select quotes ----
radioButtons("quote", "Quote",
choices = c(None = "",
"Double Quote" = '"',
"Single Quote" = "'"),
selected = '"'),
# Horizontal line ----
tags$hr(),
# Input: Select number of rows to display ----
radioButtons("disp", "Display",
choices = c(Head = "head",
All = "all"),
selected = "head")
),
# Main panel for displaying outputs ----
mainPanel(
# Output: Data file ----
tableOutput("contents")
)
)
)
server <- function(input, output) {
output$contents <- renderTable({
# input$file1 will be NULL initially. After the user selects
# and uploads a file, head of that data file by default,
# or all rows if selected, will be shown.
req(input$file1)
# when reading semicolon separated files,
# having a comma separator causes `read.csv` to error
tryCatch(
{
df <- read.csv(input$file1$datapath,
header = F,
sep = input$sep,
quote = input$quote,
col.names = c("COL1","COL2","COL3","COL4","COL5"),
check.names = F)
},
validate(
need(file_ext(input$file1$datapath) %in% c(
'text/csv',
'text/comma-separated-values',
'text/tab-separated-values',
'text/plain',
'csv'
), "Data was not recognized. Please use a CSV file!")),
error = function(e) {
# return a safeError if a parsing error occurs
stop(safeError(e))
}
)
if(input$disp == "head") {
return(head(df))
}
else {
return(df)
}
})
}
shinyApp(ui,server)
我试图构建一个示例程序,用户只能上传只有 5 列的 csv 数据集。您可以根据您的要求进行更改。
UI.R
library(shiny)
library(shinydashboard)
library(shinyjs)
library(shinyalert)
dashboardPage(
dashboardHeader(title = "Basic dashboard"),
dashboardSidebar(
sidebarMenu(
menuItem("Dashboard", tabName = "dashboard", icon = icon("dashboard"))
)
),
dashboardBody(
useShinyalert(),
tabItems(
tabItem(tabName = "dashboard",
fluidRow(
column(3,
fileInput("file1", "Choose CSV File",
multiple = FALSE,
accept = c("text/csv",
"text/comma-separated-values,
text/plain",
".csv"))
)
),
fluidRow(
tableOutput("contents")
)
)
)
)
)
Server.R
library(shiny)
library(shinydashboard)
shinyServer(function(input,output){
output$contents <- renderTable({
inFile <- input$file1
if (is.null(inFile))
{
returnValue()
}
else
{
data<-read.csv(inFile$datapath)
if(ncol(data)<5)
{
shinyalert("Column Error","Uploaded Data has less than 5 Col",type="error")
returnValue()
}
else if(ncol(data)>5)
{
shinyalert("Column Error","Uploaded Data has more than 5 Col",type = "error")
returnValue()
}
else
{
return(data)
}
}
})
})