我有一个应用程序的服务器文件,它从yahoo finance获取股票信息,来自用户输入的股票代码。这里相关的服务器代码是
dataInput <- reactive({
getSymbols(input$symb, src = "yahoo",
from = input$dates[1],
to = input$dates[2],
auto.assign = FALSE)
})
,ui.r代码是
textInput("symb", "Symbol", "^FTSE"),
dateRangeInput("dates",
"Date range",
start = "2015-01-01",
end = as.character(Sys.Date())),
submitButton("Analysis"),width=6)
这给出了以下
但是,如果用户输入的符号不正确或不是股票,我会收到以下错误
Error in download.file(paste(yahoo.URL, "s=", Symbols.name, "&a=", from.m, :
cannot open URL 'http://ichart.finance.yahoo.com/table.csv?s=sdf&a=11&b=16&c=2014&d=1&e=25&f=2015&g=d&q=q&y=0&z=sdf&x=.csv'
这很好,因为它不能打开网址,因为他们输入的符号不存在股票。但是,我想要一个弹出消息,说它们已经插入了一个库存符号。我已经尝试过这样做的方法,包括bsAlert()方法,但我似乎无法做到这一点。任何帮助都会很棒
答案 0 :(得分:0)
获取符号时可以使用try/catch
,如果出现错误,则会显示bsAlert
:
<强> app.R 强>
library(quantmod)
library(shinyBS)
server<-function(input, output,session) {
#get the symbol data
symbolData<-reactive({
#try/catch in case there is an error
data<-tryCatch({
#if there is a bsAlert, close it
closeAlert(session, "alert")
#try to get the symbols
getSymbols(input$symb, src = "yahoo",
from = input$dates[1],
to = input$dates[2],
auto.assign = FALSE)},
#if there is an error
error=function(cond) {
#create the bsAlert
createAlert(session, inputId = "alert_anchor",
alertId="alert",
message = "Please enter a valid symbol",
type = "warning",
append="false",
dismiss = FALSE
)
#return an empty string
return("")
})
data
})
#as an example, output the table
output$table<-renderDataTable({symbolData()})
}
ui<-fluidPage(
fluidRow(
column(3, wellPanel(
textInput("symb", "Symbol", "^FTSE"),
bsAlert(inputId = "alert_anchor"),
dateRangeInput("dates",
"Date range",
start = "2015-01-01",
end = as.character(Sys.Date())),
submitButton("Submit")
)),
column(6, dataTableOutput("table"))
))
shinyApp(ui = ui, server = server)