我是R的新手，这是我在R编程中的第一个应用程序。我的应用程序从登录屏幕开始。用户登录后，主屏幕具有侧边栏菜单，其中包含4个菜单项：仪表板，配置文件，建议，调查。前3个菜单项向用户显示表输出，按预期工作。最后一个必须通过SelectInput选项和ActionButton从用户那里获取输入。这里的问题是ActionButton根本不起作用。即使在SelectInput中选择了选项之后，单击ActionButton也没有任何反应。请对此进行指导。
代码如下：
ui.R
shinyUi<- dashboardPage(
dashboardHeader(
title="Course Recommender System",
titleWidth = 400
),
dashboardSidebar(
width = 200,
sidebarMenu(id="tabs",sidebarMenuOutput("menu"))
),
dashboardBody(
tagList(
tags$head(
tags$link(rel="stylesheet", type="text/css",href="style.css"),
tags$script(type="text/javascript", src = "md5.js"),
tags$script(type="text/javascript", src = "passwdInputBinding.js"),
#########################################################################
tags$style(type="text/css",
".shiny-output-error { visibility: hidden; }",
".shiny-output-error:before { visibility: hidden; }"
)
)
),
div(class = "login",
uiOutput("uiLogin"),
textOutput("pass")
),
uiOutput("body")
)
)
Server.R
USER <- reactiveValues(Logged = Logged)
USER1 <- reactiveValues(REGISTERED = REGISTERED)
passwdInput <- function(inputId, label) {
tagList(
tags$label(label),
tags$input(id = inputId, type="password", value="")
)
}
output$uiLogin <- renderUI({
if (USER$Logged == FALSE) {
box(
textInput("userName", "User Name:",width = "200px"),
passwdInput("passwd", "Pass word:"),
br(),
textOutput("text1"),
actionButton("Login", "Log in")
)
}
})
output$pass <- renderText ({
if (USER$Logged == FALSE) {
if (!is.null(input$Login)) {
if (input$Login > 0) {
selQuery <- "select * from student_login;"
df = dbSendQuery(con,selQuery)
PASSWORD = dbFetch(df,n=-1)
PASSWORD <- as.data.frame(PASSWORD)
Username <- isolate(input$userName)
Password <- isolate(input$passwd)
Id.username <- which(PASSWORD$user_name == Username)
Id.password <- which(PASSWORD$password == Password)
if (length(Id.username) > 0 & length(Id.password) > 0) {
if (Id.username == Id.password) {
USER$Logged <- TRUE
}
}
else if (length(Id.username) <= 0 & length(Id.password) <= 0) {
output$text1 <- renderText({
"Please Register your details"
})
}
else{
output$text1 <- renderText({
"Wrong Username or Password"
})
}
}
}
}
})
observe(
if (USER$Logged == TRUE) {
output$menu <- renderMenu({
sidebarMenu(id="menu",
menuItem(text="Dashboard", tabName = "dashboard",selected="TRUE"),
menuItem(text="Academic Profile", tabName = "results"),
menuItem(text="Course Recommendations", tabName = "recommend"),
menuItem(text="Complete Survey", tabName = "survey",selected = "FALSE")
)
})
output$body <- renderUI({
tabItems(
tabItem(tabName="dashboard",
fluidRow(
box(
status = "primary",title = "Personal Information",
solidHeader = TRUE,
# tableOutput("personalinfo")
textOutput("myname"),
textOutput("myage"),
textOutput("mymobile")
)
)
),
tabItem(tabName="results",
fluidRow(
box(
status = "warning",title = "FIRST SEMESTER RESULTS",
solidHeader = TRUE,width = 6,
tableOutput("mysem1")
),
box(
status = "warning",title = "SECOND SEMESTER RESULTS",
solidHeader = TRUE,width = 6,
tableOutput("mysem2")
)
)
),
tabItem(tabName="recommend",
fluidRow(
box(
status="warning",title = "ELECTIVE COURSE LIST FOR THIS SEMESTER",
solidHeader = TRUE,width = 6,
dataTableOutput("elec_cse_list")
),
box(
status = "warning",title = "RECOMMENDED COURSE LIST",
solidHeader = TRUE,width = 6,
dataTableOutput("rec_cse_list")
)
)
),
tabItem(tabName="survey",
box(
selectInput("ch","Engg Knowledge",
c("No_impact"="no",
"Major_impact"="major",
"Minor_impact"="minor")),
actionButton("sub","Submit"),
textOutput("res")
)
)
###Code for other tabs fetching data from backend database and displaying table output
output$res<-eventReactive(input$sub,
{renderText(input$ch)} )
}
)
}
)
isolate({updateTabItems(session, "tabs", "dashboard")})
cancel.onSessionEnded <- session$onSessionEnded(function() { dbDisconnect(con) })
}