我在此link上找到了登录示例，但是我有一个问题：如何访问已登录的用户？我意识到此信息存储在名为auth的对象中，但是如何在不给出错误的情况下访问它？
# NOT RUN {
if (interactive()) {
library(shiny)
library(shinymanager)
# data.frame with credentials info
credentials <- data.frame(
user = c("1","fanny", "victor"),
password = c("1","azerty", "12345"),
comment = c("1","alsace", "auvergne"),
stringsAsFactors = FALSE
)
# app
ui <- fluidPage(
# authentication module
auth_ui(
id = "auth",
# add image on top ?
tags_top =
tags$div(
tags$h4("Demo", style = "align:center"),
tags$img(
src = "https://www.r-project.org/logo/Rlogo.png", width = 100
)
),
# add information on bottom ?
tags_bottom = tags$div(
tags$p(
"For any question, please contact ",
tags$a(
href = "mailto:someone@example.com?Subject=Shiny%20aManager",
target="_top", "administrator"
)
)
),
# change auth ui background ?
background = "linear-gradient(rgba(0, 0, 255, 0.5),
rgba(255, 255, 0, 0.5)),
url('https://www.r-project.org/logo/Rlogo.png');"
),
# result of authentication
verbatimTextOutput(outputId = "res_auth"),
# classic app
headerPanel('Iris k-means clustering'),
sidebarPanel(
selectInput('xcol', 'X Variable', names(iris)),
selectInput('ycol', 'Y Variable', names(iris),
selected=names(iris)[[2]]),
numericInput('clusters', 'Cluster count', 3,
min = 1, max = 9)
),
mainPanel(
plotOutput('plot1')
)
)
server <- function(input, output, session) {
# authentication module
auth <- callModule(
module = auth_server,
id = "auth",
check_credentials = check_credentials(credentials)
)
output$res_auth <- renderPrint({
reactiveValuesToList(auth) ## <---- this line print which user is logged in
})
# classic app
selectedData <- reactive({
req(auth$result) # <---- dependency on authentication result
iris[, c(input$xcol, input$ycol)]
})
clusters <- reactive({
kmeans(selectedData(), input$clusters)
})
output$plot1 <- renderPlot({
palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
"#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"))
par(mar = c(5.1, 4.1, 0, 1))
plot(selectedData(),
col = clusters()$cluster,
pch = 20, cex = 3)
points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
})
}
shinyApp(ui, server)
}
如何访问auth $ user？下标越界错误正在发生，我想访问在应用程序内标记为“ <------”的行上正在打印的“ auth”对象中的用户，该行将打印已登录的用户”。在我看来，如何使用反应式对象是一个错误。
我的个人情况：我正在尝试向MySQL数据库发送查询，如下所示：
user_data <- reactive({
req(auth$result)
auth$user
})
connection<-reactivePoll( intervalMillis = 300,session,checkFunc = function(){
storiesDb <- dbConnect(RMariaDB::MariaDB(), user='USER', password=localuserpassword, dbname='USER', host='localhost')
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",user_data(),"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs) },
valueFunc = function(){
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",user_data(),"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
}
)
我尝试使用user_data（），并给出错误：“无法为签名”“ MariaDBConnection”，“ reactiveExpr””'”找到函数'dbSendQuery'的继承方法
connection<-reactivePoll( intervalMillis = 300,session,checkFunc = function(){
storiesDb <- dbConnect(RMariaDB::MariaDB(), user='USER', password=localuserpassword, dbname='USER', host='localhost')
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs) },
valueFunc = function(){
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
}
)
我尝试使用auth $ user，并给出错误：“ as.vector（x，“ character”）错误：无法将类型'closure'强制转换为'character'类型的vector“
connection<-reactivePoll( intervalMillis = 300,session,checkFunc = function(){
storiesDb <- dbConnect(RMariaDB::MariaDB(), user='USER', password=localuserpassword, dbname='USER', host='localhost')
querysel1=paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs) },
valueFunc = function(){
querysel1=paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
}
)
我在querysel1中尝试了无反应式，并给出了空错误：“ Error：”
在我看来，所有这些错误都是由于服务器内部的反应对象而发生的。
答案 0 :(得分：1)
感谢提供reactivePoll的更多信息，我想我发现了问题：
这里的问题在于执行reactivePoll。启动应用程序时，reactivePoll已经开始执行，但是尚未登录任何用户。这意味着auth$user尚不存在（它是NULL），并且checkFun和valueFun中的代码无法处理。我提供了一个小示例（使用user = 1和password = 1）来说明它在原理上是可行的。只要auth$user为NULL，我就确保不执行代码：
library(shiny)
library(shinymanager)
# data.frame with credentials info
credentials <- data.frame(
user = c("1","fanny", "victor"),
password = c("1","azerty", "12345"),
comment = c("1","alsace", "auvergne"),
stringsAsFactors = FALSE
)
# app
ui <- fluidPage(
# authentication module
auth_ui(
id = "auth",
# add image on top ?
tags_top =
tags$div(
tags$h4("Demo", style = "align:center"),
tags$img(
src = "https://www.r-project.org/logo/Rlogo.png", width = 100
)
),
# add information on bottom ?
tags_bottom = tags$div(
tags$p(
"For any question, please contact ",
tags$a(
href = "mailto:someone@example.com?Subject=Shiny%20aManager",
target="_top", "administrator"
)
)
),
# change auth ui background ?
background = "linear-gradient(rgba(0, 0, 255, 0.5),
rgba(255, 255, 0, 0.5)),
url('https://www.r-project.org/logo/Rlogo.png');"
),
# result of authentication
verbatimTextOutput(outputId = "res_auth"),
# classic app
headerPanel('Iris k-means clustering'),
sidebarPanel(
selectInput('xcol', 'X Variable', names(iris)),
selectInput('ycol', 'Y Variable', names(iris),
selected=names(iris)[[2]]),
numericInput('clusters', 'Cluster count', 3,
min = 1, max = 9)
),
mainPanel(
plotOutput('plot1'),
textOutput("user_name")
)
)
server <- function(input, output, session) {
# authentication module
auth <- callModule(
module = auth_server,
id = "auth",
check_credentials = check_credentials(credentials)
)
output$res_auth <- renderPrint({
reactiveValuesToList(auth) ## <---- this line print which user is logged in
})
# the following line is just an example how to use auth$user in a different
# reactive
user_data <- reactive({
auth$user
})
# call the new reactive in a render function
output$user_name <- renderText({
paste0("The user currently logged in is: ", user_data())
})
# classic app
selectedData <- reactivePoll(intervalMillis = 1000,
session,
checkFunc = function() {
if (!is.null(auth$user) && auth$user == "1") {
rnorm(1)
} else {
1
}
},
valueFunc = function() {
n_row <- sample(1:150, 120)
iris[n_row, c(input$xcol, input$ycol)]
})
clusters <- reactive({
kmeans(selectedData(), input$clusters)
})
output$plot1 <- renderPlot({
palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
"#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"))
par(mar = c(5.1, 4.1, 0, 1))
plot(selectedData(),
col = clusters()$cluster,
pch = 20, cex = 3)
points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
})
}
shinyApp(ui, server)
我不确定为什么，但是仅添加req(auth$user)在这里行不通。
您可以执行以下操作：
connection<-reactivePoll( intervalMillis = 300,
session,
checkFunc = function(){
if (!is.null(auth$user)) {
storiesDb <- dbConnect(RMariaDB::MariaDB(), user='USER', password=localuserpassword, dbname='USER', host='localhost')
querysel1=paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
} else {
NULL
}
},
valueFunc = function(){
if (!is.null(auth$user)) {
querysel1=paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
} else {
NULL
}
}
)
在这里，只要NULL不存在，我就返回auth$user，您可以根据需要进行调整。
我不确定您的问题/错误到底发生在哪里。对我来说，您的示例有效。我添加了另一个示例，说明如何访问auth$user。由于它是响应式的，因此只能在响应式上下文中访问它。
library(shiny)
library(shinymanager)
# data.frame with credentials info
credentials <- data.frame(
user = c("1","fanny", "victor"),
password = c("1","azerty", "12345"),
comment = c("1","alsace", "auvergne"),
stringsAsFactors = FALSE
)
# app
ui <- fluidPage(
# authentication module
auth_ui(
id = "auth",
# add image on top ?
tags_top =
tags$div(
tags$h4("Demo", style = "align:center"),
tags$img(
src = "https://www.r-project.org/logo/Rlogo.png", width = 100
)
),
# add information on bottom ?
tags_bottom = tags$div(
tags$p(
"For any question, please contact ",
tags$a(
href = "mailto:someone@example.com?Subject=Shiny%20aManager",
target="_top", "administrator"
)
)
),
# change auth ui background ?
background = "linear-gradient(rgba(0, 0, 255, 0.5),
rgba(255, 255, 0, 0.5)),
url('https://www.r-project.org/logo/Rlogo.png');"
),
# result of authentication
verbatimTextOutput(outputId = "res_auth"),
# classic app
headerPanel('Iris k-means clustering'),
sidebarPanel(
selectInput('xcol', 'X Variable', names(iris)),
selectInput('ycol', 'Y Variable', names(iris),
selected=names(iris)[[2]]),
numericInput('clusters', 'Cluster count', 3,
min = 1, max = 9)
),
mainPanel(
plotOutput('plot1'),
textOutput("user_name")
)
)
server <- function(input, output, session) {
# authentication module
auth <- callModule(
module = auth_server,
id = "auth",
check_credentials = check_credentials(credentials)
)
output$res_auth <- renderPrint({
reactiveValuesToList(auth) ## <---- this line print which user is logged in
})
# the following line is just an example how to use auth$user in a different
# reactive
user_data <- reactive({
auth$user
})
# call the new reactive in a render function
output$user_name <- renderText({
paste0("The user currently logged in is: ", user_data())
})
# classic app
selectedData <- reactive({
req(auth$result) # <---- dependency on authentication result
iris[, c(input$xcol, input$ycol)]
})
clusters <- reactive({
kmeans(selectedData(), input$clusters)
})
output$plot1 <- renderPlot({
palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
"#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"))
par(mar = c(5.1, 4.1, 0, 1))
plot(selectedData(),
col = clusters()$cluster,
pch = 20, cex = 3)
points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
})
}
shinyApp(ui, server)
答案 1 :(得分：1)
要详细说明我的评论，也许最好显示代码：
请在注释中查看哪些语句有效，哪些无效。我只是将用户victor与通行证12345一起使用，而没有检查它是否与其他凭据一起使用。
library(shiny)
library(shinymanager)
# data.frame with credentials info
credentials <- data.frame(
user = c("1","fanny", "victor"),
password = c("1","azerty", "12345"),
comment = c("1","alsace", "auvergne"),
stringsAsFactors = FALSE
)
# app
ui <- fluidPage(
# authentication module
auth_ui(
id = "auth",
# add image on top ?
tags_top =
tags$div(
tags$h4("Demo", style = "align:center"),
tags$img(
src = "https://www.r-project.org/logo/Rlogo.png", width = 100
)
),
# add information on bottom ?
tags_bottom = tags$div(
tags$p(
"For any question, please contact ",
tags$a(
href = "mailto:someone@example.com?Subject=Shiny%20aManager",
target="_top", "administrator"
)
)
),
# change auth ui background ?
background = "linear-gradient(rgba(0, 0, 255, 0.5),
rgba(255, 255, 0, 0.5)),
url('https://www.r-project.org/logo/Rlogo.png');"
),
# result of authentication
verbatimTextOutput(outputId = "res_auth"),
# classic app
headerPanel('Iris k-means clustering'),
sidebarPanel(
selectInput('xcol', 'X Variable', names(iris)),
selectInput('ycol', 'Y Variable', names(iris),
selected=names(iris)[[2]]),
numericInput('clusters', 'Cluster count', 3,
min = 1, max = 9)
),
mainPanel(
plotOutput('plot1')
)
)
server <- function(input, output, session) {
# authentication module
auth <- callModule(
module = auth_server,
id = "auth",
check_credentials = check_credentials(credentials)
)
output$res_auth <- renderPrint({
# reactiveValuesToList(auth$user) ## <---- not working
auth[["user"]] ## <---- working
# auth$user ## <---- this works too
# reactiveValuesToList(auth)[["user"]] # <--- this works too
})
# classic app
selectedData <- reactive({
req(auth$result) # <---- dependency on authentication result
iris[, c(input$xcol, input$ycol)]
})
clusters <- reactive({
kmeans(selectedData(), input$clusters)
})
output$plot1 <- renderPlot({
palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
"#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"))
par(mar = c(5.1, 4.1, 0, 1))
plot(selectedData(),
col = clusters()$cluster,
pch = 20, cex = 3)
points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
})
}
shinyApp(ui, server)
}