I found this example of login on this link, but I had a question: how do I access the user who is logged in? I realized that this information is stored in the object called auth, but how to access it without giving an error?
# 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)
}
how to access auth$user? subscript out of bounds error is happening, I wanted to access the user who is in the "auth" object that is being printed inside the app on the line marked "<-------this line print which user is logged in". it seems to me an error on how to use a reactive object.
My personal case: I am trying to send a query to a MySQL database, as follows:
- Attempt 1 (using user_data() )
user_data <- reactive({
req(auth$result)
auth$user
})
connection<-reactivePoll( intervalMillis = 300,session,checkFunc = function(){
storiesDb <- dbConnect(RMariaDB::MariaDB(), user='USER', password=localuserpassword, dbname='USER', host='localhost')
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",user_data(),"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs) },
valueFunc = function(){
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",user_data(),"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
}
)
I tried to use user_data(), and gave the error: "unable to find an inherited method for function ‘dbSendQuery’ for signature ‘"MariaDBConnection", "reactiveExpr"’'"
- Attempt 2 (without using user_data() )
connection<-reactivePoll( intervalMillis = 300,session,checkFunc = function(){
storiesDb <- dbConnect(RMariaDB::MariaDB(), user='USER', password=localuserpassword, dbname='USER', host='localhost')
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs) },
valueFunc = function(){
querysel1=reactive({paste("SELECT COL1
FROM TABLENAME
where id ='",auth$user,"' ",sep= ''
)})
rs = dbSendQuery(storiesDb,querysel1)
dbFetch(rs)
}
)
I tried to use auth$user, and gave the error: "Error in as.vector (x," character "): cannot coerce type 'closure' to vector of type 'character'"
- Attempt 3 (without reactive in querysel1)
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)
}
)
I tried without reactive in querysel1, and gave the empty error: " Error : "
It seems to me that all these errors happen because of the reactive object inside the server.