I am new to JavaScript and very new to node.js framework, just started using it a few days ago. My apologies if my code is nonsensical, the whole idea of promises and callbacks is still sinking in. That being said my question is the following I am trying to figure out if certain request to websites are successful or cause an error based on the range of their status code response. I am working with an array of websites and what I've done so far is below, I do however get a TypeError: Cannot read property 'then' of undefined
on my local machine with node.js installed and can't figure out why.
const sample = [
'http://www.google.com/',
'http://www.spotify.com/us/',
'http://twitter.com/',
'http://google.com/nothing'
]
const http = require('http')
const getStatusCodeResult = (website) => {
http.get(website, (res) => {
return new Promise((resolve, reject) => {
setTimeout(() => {
let statusCode = res.statusCode
error = statusCode >= 400 && statusCode <= 500 ? `error: ${website}`: null
if (error) {
reject(error)
} else if (statusCode >= 200 && statusCode <= 300) {
resolve(`Success: ${website}`)
}
}, 0)
})
})
}
// LOOP PROMISES
const getAllStatusCodeResult = (websites) => {
websites.forEach((website) => {
getStatusCodeResult(website)
.then((result) => {
console.log(result)
})
.catch(error => {
console.log('error', error)
})
})
}
getAllStatusCodeResult(sample)
Ideally I would want the result to be printed as the example below, but for now I am just using console.log
to figure out if the code even works.
// Example Printout
{
success: ['https://www.google.com/', 'https://www.spotify.com/us/',
'https://twitter.com /' ],
error: [''http://google.com/nothing']
}
You mixed up the first two lines. The new Promise
wrapper that gets you the value to return needs to be on the outside, and the http.get
call should be inside its executor callback. Also you don't really need that timeout:
function getStatusCodeResult(website) {
return new Promise((resolve, reject) => {
http.get(website, (res) => {
let statusCode = res.statusCode,
error = statusCode >= 400 && statusCode <= 500 ? `error: ${website}`: null
if (error) {
reject(error)
} else if (statusCode >= 200 && statusCode <= 300) {
resolve(`Success: ${website}`)
}
})
})
}