In the following node function, it is returning an empty array. Not sure why its doing that. Could this be a async await issue? Would appreciate any help. Thank you
const folderPath = '/public/home.html'
function getCircuitAndFuse(folderPath){
//List containing circuit name with its fuse
let temporaryList = [];
let finalCircuitAndFuseList = []
fs.readFile(__dirname + folderPath, (error, data)=>{
if(error){
console.log(`Unable to read file: ${error}`)
}else{
var $ = cheerio.load(data)
$('img').each(function(index, element){
let getClassAtr = element.attribs.class
temporaryList.push(getClassAtr.slice(0, getClassAtr.lastIndexOf(" ")))
})
finalCircuitAndFuseList = [...new Set(temporaryList)]
}
})
return finalCircuitAndFuseList;
}
let getInfo = getCircuitAndFuse(folderPath)
// Returning empty array
console.log(getInfo)
***Server code****
const server = http.createServer(function(req, res){
res.writeHead(200, {'Content-Type': 'text/plain'})
res.end()
}).listen(port, ()=>{
console.log(`Server listening on port ${port}. Press Ctrl-C to terminate...`)
})
getCircuitAndFuse must return Promise like this:
function getCircuitAndFuse(folderPath) {
return new Promise((resolve, reject) => {
//List containing circuit name with its fuse
let temporaryList = [];
fs.readFile(__dirname + folderPath, (error, data) => {
if (error) {
console.log(`Unable to read file: ${error}`);
} else {
var $ = cheerio.load(data);
$('img').each(function (index, element) {
let getClassAtr = element.attribs.class;
temporaryList.push(
getClassAtr.slice(0, getClassAtr.lastIndexOf(' '))
);
});
resolve([...new Set(temporaryList)]);
}
});
});
}
getCircuitAndFuse(folderPath).then((getInfo) => {
// do something with `getInfo`
});
Another alternative to Faruk's answer would be to just use fs.readFileSync instead of wrapping your function in a promise and requiring some of that extra ceremony. Using fs.readFileSync will ensure that your function doesn't return prematurely.
Here is your code rewritten with that in mind:
function getCircuitAndFuse(folderPath) {
try {
let temporaryList = [];
const data = fs.readFileSync(__dirname + folderPath);
const $ = cheerio.load(data);
$("img").each(function (index, element) {
let getClassAtr = element.attribs.class;
temporaryList.push(getClassAtr.slice(0, getClassAtr.lastIndexOf(" ")));
});
return [...new Set(temporaryList)];
} catch (error) {
console.log(error);
}
}