I am using Angular 5 and want to return data from function getDionaeaResults in json format after subscribing to service
getDionaeaResults(sql) : any {
this.dionaeaService.getDionaeaConnectionLogs(sql).subscribe(res => {
this.data = res;
}),
(error: any) => {
console.log(error);
});
return this.data;
}
After calling this function, this.totalAttacks prints undefined.
getTotalAttack() {
this.totalAttacks = this.getDionaeaResults("some query")
console.log(this.totalAttacks,'attacks')
}
Would suggest using the Obseravable .map() function.
getDionaeaResults(sql) : Observable<any> {
return this.dionaeaService
.getDionaeaConnectionLogs(sql)
.map(res => res);
}
getTotalAttack(sql){
this.getDionaeaResults("some query")
.subscribe(
res => { this.totalAttacks = res; },
err => { console.log(err); }
);
}
this.getDionaeaResults is returning undefined because the service you're calling is asynchronous you have to wait for the subscribe callback. as Observables are asynchronous calls
this.data=res
might execute after the return statement. You can perhaps call that dionaeaService directly inside getTotalAttack() function, like this:
getTotalAttack(sql){
this.dionaeaService.getDionaeaConnectionLogs(sql).subscribe(res => {
this.totalAttacks = res;
}),
(error: any) => {
console.log(error);
});
}
Related
I am going to use vonage for text service.
However, only node.js syntax exists, and the corresponding API is being used.
There is a phenomenon that the callback is executed later when trying to receive the values returned from the callback to check for an error.
How can I solve this part? The code is below.
await vonage.message.sendSms(from, to, text, async (err, responseData) => {
if (err) {
console.log('1');
result.message = err;
} else {
if (responseData.messages[0]['status'] === '0') {
console.log('2');
} else {
console.log('3');
result.error = `Message failed with error: ${responseData.messages[0]['error-text']}`;
}
}
});
console.log(result);
return result;
When an error occurs as a result of executing the above code,
result{error:undefined}
3
Outputs are in order.
From what I can understand the issue is that you are passing a async callback. you could simply just give vonage.message.sendSms() a synchronous callback like so.
const result = {};
vonage.message.sendSms(from, to, text, (err, responseData) => {
if (err) {
console.log('1');
result.message = err;
} else {
if (responseData.messages[0]['status'] === '0') {
console.log('2');
} else {
console.log('3');
result.error = `Message failed with error: ${responseData.messages[0]['error-text']}`;
}
}
});
if you want to use async or promises I would suggest something like this
const sendSMS = (from, to, text) => new Promise( (resolve, reject) => {
vonage.message.sendSms(from, to, text, (err, responseData) => {
if (err) {
reject(err);
} else {
resolve(responseData);
}
});
});
// elsewhere
sendSMS(from, to, text)
.then(...)
.catch(...);
methods: {
getHomeInfo() {
axios.get("/js/index.json").then(this.getHomeInfoSucc());
//err：undefined
axios.get("/js/index.json").then(function(res) {
console.log(res.data);
});
//Data available
},
getHomeInfoSucc(res) {
console.log(res);
}
}
I used Axios in Vue to use the anonymous function in Axios's then () to get data, but in then (), I call the function in methods to get the response data undefined
You need a callback:
methods: {
getHomeInfo() {
axios.get("/js/index.json").then((res) => this.getHomeInfoSucc(res));
//err：undefined
axios.get("/js/index.json").then(function(res) {
console.log(res.data);
});
//Data available
},
getHomeInfoSucc(res) {
console.log(res);
}
}
I am able to add an interceptor for the Axios pipeline. Also, I need the loader to be conditional based. The situation is some requests can run in the background and don't need a loader to be blocking the UI. In such cases, I will be able to let the Axios know by sending an extra parameter saying isBackground call. How can I achieve this?
axios.interceptors.request.use((config) => {
this.isLoading = true; // Or trigger start loader
return config
}, (error) => {
this.isLoading = false // Or trigger stoploader
return Promise.reject(error)
})
axios.interceptors.response.use((response) => {
this.isLoading = false // Or trigger stoploader
return response
}, function(error) {
this.isLoading = false // Or trigger stoploader
return Promise.reject(error)
})
Just use your own custom property isBackground on the config like this:
axios.interceptors.request.use((config) => {
console.log(config.isBackground)
return config
}, (error) => {
console.log(error.config.isBackground)
return Promise.reject(error)
})
axios.interceptors.response.use((response) => {
console.log(response.config.isBackground)
return response
}, function(error) {
console.log(error.config.isBackground)
return Promise.reject(error)
})
const config = {
isBackground: true
}
axios.get('https://httpbin.org/get', config)
.then(response => {
console.log(response)
})
.catch(error => {
console.log(error)
})
Note that there is a bug in current release 0.19.0 waiting to be fixed, which breaks this functionality. Works ok in version 0.18...
Fiddle
I'm struggling with migrating a HAPI function that verifies a JWT token and then makes a database call using the decoded credentials.
The problem is that jwt.verify uses a callback, but Hapi and Hapi.MySQL2 have both been updated to use async functions
The main function is as follows
exports.LoadAuth = (req, h) => {
let token = req.headers.authorization.split(' ')[1]
VerifyToken(token, async function (err, decoded) {
if (!err) {
let sql = '#SELECT STATEMENT USING decoded.id'
const [data] = await mfjobs.query(sql, decoded.id)
let auids = []
data.forEach(function (ag) {
auids.push(ag.Name)
})
auids = base64(auids.toString())
return auids
} else {
return {message: 'Not Authorised'}
}
})
}
The VerifyToken function is as follows:
VerifyToken = (tok, done) => {
jwt.verify(tok, Buffer.from(secret, 'base64'), function (err, decTok) {
if (err) {
done(err)
} else {
done(null, decTok)
}
})
}
Debugging everything above works up to the point that the data should be returned to the front end. At which point I get an ERROR 500
I know that the issue is with the VerifyToken function as if I omit this and hard code the decoded.id into the query the correct data reaches the front end.
Any pointers?
You can convert your VerifyToken function to Promises.
let VerifyToken = (tok) => {
return new Promise((resolve, reject) => {
jwt.verify(tok, Buffer.from(secret, 'base64'), function (err, decTok) {
if (err) {
reject(err)
} else {
resolve(decTok)
}
})
});
}
Now you have a function that you can use with async await notation and internally checks jwt validation via callbacks.
Then we can slightly modify your controller as follows.
exports.LoadAuth = async (req, h) => {
let token = req.headers.authorization.split(' ')[1];
try {
let decoded = await VerifyToken(token);
let sql = '#SELECT STATEMENT USING decoded.id';
const [data] = await mfjobs.query(sql, decoded.id);
let auids = [];
data.forEach(function (ag) {
auids.push(ag.Name)
});
auids = base64(auids.toString());
return auids
} catch (e) {
return {message: 'Not Authorised'}
}
}
We just converted your handler function to async function, and we already have a VerifyToken function that returns a promise so, we can call it with the await operator.
I want to combine the results of 2 queries and then return them as one, like this:
test: async (req, res) => {
const valOne = TableOne.find({ id: id })
.exec((err, result) => {
if (err) {
res.serverError(err);
}
return result;
});
const valTwo = TableTwo.find({ id: id })
.exec((err, result) => {
if (err) {
res.serverError(err);
}
return result;
});
const data = {
keyOne: valOne,
keyTwo: valTwo,
};
res.json(data);
}
I understand above code won't return because it's async. How can I achieve this?
There is not much info you supply: node version, sails version, etc.
There are several approaches here:
1. Using promises
2. Using callback chaining
3. Using await/async
If you use sails 1.0 and node >= 8, your best bet is to use await/async, so your code should work like that:
test: async (req, res) => {
let valOne, valTwo;
try {
valOne = await TableOne.find({ id: id });
valTwo = await TableTwo.find({ id: id });
} catch (err) {
return res.serverError(err); //or res.badRequest(err);
}
const data = {
keyOne: valOne,
keyTwo: valTwo,
};
res.json(data);
}