i want to load a new page when a function throws an error-CodePudding

I want to load a new error page when a function throws an error.

I want to show an error page whenever error is thrown but the page is stuck at loading screen and there are error messages on my log. Now if the function getStockPoints throws an error and if i export this function to app.js and call it there with try and catch block it catches the error but the page is just stuck at loading. i want it to go to an error page


module.exports = {
  async getStocks () {
    return stocks
  },
  async getStockPoints (stockName, timestamp) {
    if (Math.random() < FAILUE_RATE) {
      throw new Error('Failed to generate stock data')
    }
    if (!stocks.includes(stockName)) {
      throw new Error(`Uknown stock ${stockName}`)
    }
    const timestamps = getTimestamps( timestamp, 10)
    return getSeries(stockName, timestamps).map((value, idx) => ({
      value,
      timestamp: timestamps[idx]
    }))
  }
}

i did the try catch method and tried to load a new page but it does not work.

app.get('/stocks/:symbol', async (req, res) => {
  const { params: { symbol } } = req
  try{
    const data = await stocks.getStockPoints(symbol, new Date())
    res.render('stockPoints', {DATA: data})
  }
  catch(e){
    console.log("ERRORs: ")
    console.error(e)
  }
})

ERROR MESSAGES ARE GIVEN BELOW the page is now stuck at loading

Error: Uknown stock df
    at Object.getStockPoints (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\stocks.js:47:13)
    at C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\app.js:24:31
    at Layer.handle [as handle_request] (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\layer.js:95:5)
    at next (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\route.js:144:13)
    at Route.dispatch (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\route.js:114:3)
    at Layer.handle [as handle_request] (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\layer.js:95:5)
    at C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\index.js:284:15
    at param (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\index.js:365:14)
    at param (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\index.js:376:14)
    at Function.process_params (C:\Users\talha_znbd0fl\Desktop\JavaScript-Challenge-master-main\JavaScript-Challenge-master-main\node_modules\express\lib\router\index.js:421:3)

CodePudding user response：

You are stuck at a loading page because your server never responds to the request. There are multiple functions you can call to serve a result, but if you likely want to render an error page. To do this, all you have to do is call res.render inside your exception handler. Just like this:

app.get('/stocks/:symbol', async (req, res) => {
  const { params: { symbol } } = req
  try{
    const data = await stocks.getStockPoints(symbol, new Date())
    res.render('stockPoints', {DATA: data})
  } catch (e){
    console.log("ERRORs: ")
    console.error(e)
    res.render('errorPage')
  }
})

Then, create the template errorPage. It can be anything, but here's something simple to get you started:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Error</title>
</head>
<body>
    <h1>An error occured</h1>
</body>
</html>