Get async results within .map function - dictionary

I'm trying to get photos in map function from Nest.js server. This is slider component. I give an array of slides as input and show on within a map.
The thing is, I need to get real file from server (by res.sendFile..) while doing .map.
I searched and tried a few variants, this is the last, but still get errors.
what do I do wrong? Please, help
const Slider = async ({videos}) => {
async function getImageHandler(fileName) {
return getImageFromNestServer(fileName).then(async (response) => {
const fileType = await FileType.fromBuffer(response.data);
return `data:${fileType.mime};base64, ${ArrayBufferConverter.encode(response.data)}`;
})
}
let realImg = await Promise.all(
videos.map(async video => {
try {
video.fetchItem = await getImageHandler(video.content_preview_photo.filename)
return video;
} catch(err) {
throw err;
}
}
)
)
return (<MySlide>...</MySlide>)
}

Related

Why is the asnyc/await function not been waited?

I am doing an Image Upload feature with Cloudinary. I'm providing an array which may contains base64coded or uploaded image which is a url :
[
"https://res.cloudinary.com/\[userName\]/image/upload/v167xxxx4/luxxxfsgasxxxxxx7t9.jpg", "https://res.cloudinary.com/doeejabc9/image/upload/v1675361225/rf6adyht6jfx10vuzjva.jpg",
"data:image/jpeg;base64,/9j/4AAUSkZJRgABAQEBLAEsAA.......", "data:image/jpeg;base64,/9j/4AAUSkZJRgABAQEBLAEsAA......."
]
I'm using this function to upload the "un-uploaded", which returns the all uploaded version:
export async function uploadImage(el: string[]) {
const partition = el.reduce(
(result: string[][], element: string) => {
element.includes("data:image/")
? result[0].push(element)
: result[1].push(element);
return result;
},
[[], []]
);
for (let i = 0; i < partition[0].length; i++) {
const data = new FormData();
data.append("file", partition[0][i]);
data.append("upload_preset", "my_preset_name");
const res = await fetch(
"https://api.cloudinary.com/v1_1/userName/image/upload",
{
method: "POST",
body: data,
}
);
const file = await res.json();
partition[1].push(file.secure_url);
console.log(partition[1]);
}
return partition[1];
}
Then I will use the return value to update the state and call the api to update database:
const uploaded = await uploadImage(el[1])
console.log(uploaded);
setFinalVersionDoc({
...chosenDocument,
[chosenDocument[el[0]]]: uploaded,
});
However, it always updates the useState before the console.log(uploaded). I thought async/await would make sure the value is updated before moving on.
The GitHub repo is attached for better picture. The fragment is under EditModal in the 'component/document' folder:
https://github.com/anthonychan1211/cms
Thanks a lot!
I am hoping to make the upload happen before updating the state.
The function is correct, but you are trying to await the promise inside the callback function of a forEach, but await inside forEach doesn't work.
This doesn't work:
async function handleEdit() {
const entries = Object.entries(chosenDocument);
entries.forEach(async (el) => { // <------ the problem
if (Array.isArray(el[1])) {
const uploaded = await uploadImage(el[1]);
el[1].splice(0, el[1].length, uploaded);
}
});
[...]
}
If you want to have the same behaviour (forEach runs sequentially), you can use a for const of loop instead.
This works (sequentially)
(execution order guaranteed)
async function handleEdit() {
const entries = Object.entries(chosenDocument);
for (const el of entries) {
// await the promises 1,2,...,n in sequence
if (Array.isArray(el[1])) {
const uploaded = await uploadImage(el[1]);
el[1].splice(0, el[1].length, uploaded);
}
}
}
This also works (in parallel)
(execution order not guaranteed)
async function handleEdit() {
const entries = Object.entries(chosenDocument);
await Promise.all(entries.map(async (el) => {
// map returns an array of promises, and await Promise.all() then executes them all at the same time
if (Array.isArray(el[1])) {
const uploaded = await uploadImage(el[1]);
el[1].splice(0, el[1].length, uploaded);
}
}));
[...]
}
If the order in which your files are uploaded doesn't matter, picking the parallel method will be faster/better.

Jasmine 4: Async function did not complete within 5000ms issue

I have an existing async function:
async doJSONGetRequest(getUrl, accessToken) {
return new Promise(function(resolve, reject) {
const reqHeaders = {
'Content-Type': 'application/json',
'Authorization': `Bearer ${accessToken}`,
};
console.info('url = ' + getUrl);
request.get({
url: getUrl,
headers: reqHeaders,
}, function(err, response) {
if (err) return reject(err);
try {
// console.debug(`response = ${response.body}`);
const parsed = JSON.parse(response.body);
return resolve(parsed);
} catch (err) {
return reject(err);
}
});
});
}
}
I'm trying to test it with Jasmine(v4).
Of course, I don't want this thing to actually make an HTTP request, so I tried rigging up a spy on the 'request' package's 'get' function in the 'beforeAll' section:
describe('RAPIDAPIService', function() {
beforeAll(async function() {
spyOn(request, 'get')
.and
.callFake(async (parameters) => {
if (parameters.url === 'http://localhost/api/getSomething') {
const rsp = {};
rsp.body = 'good stuff';
return rsp;
} else if (parameters.url === 'http://localhost/api/whoops') {
return new Error('401 not found');
} else {
return null;
}
});
});
it('doJSONGetRequest should run successfully', async () => {
expect(api.doJSONGetRequest).toBeDefined();
const res = await api.doJSONGetRequest('http://localhost/api/getSomething', '12345678');
expect(data).toEqual('good stuff');
});
it('doJSONGetRequest should resolve errors properly', async () => {
expect(api.doJSONGetRequest).toBeDefined();
const res = await api.doJSONGetRequest('http://localhost/api/whoops', '12345678');
const expectedError = new Error('401 not found');
expect(res).toEqual(expectedError);
});
Console log statements seem to indicate that I'm actually getting past / returning something from my "await" calls in the "it" tests. But the spies are actually working / detecting that the url's have been called.
(Note that I'm not including here other tests in the same file that do not make asynchronous calls and ARE working... just so you know that there's no problem accessing the actual "api" library and its functions.)
These two tests keep failing with "Error: Timeout - Async function did not complete within 5000ms". And like I said, it seems like they're not returning back to the tests from their calls to the doJSONGetRequest function.
Any thoughts?
Thanks!
I am thinking the issue is the mocking. request.get seems to take two parameters and I am thinking you need to call the 2nd parameter (callback function) once you are done so the resolve can be called.
Try this:
spyOn(request, 'get')
.and
// add callbackFunction as 2nd argument
.callFake((parameters, callbackFunction) => {
if (parameters.url === 'http://localhost/api/getSomething') {
const rsp = {};
rsp.body = 'good stuff';
callbackFunction(null, rsp);
} else if (parameters.url === 'http://localhost/api/whoops') {
callbackFunction({ error: '401 not found' }, {});
} else {
callbackFunction(null, null);
}
});

Cloud Function with Multiple Triggers - Scheduled and onCall

I have a cloud function that I would like to run whenever a user performs a set of actions on the web app AND daily at a specified time. In the interest of not duplicating code and future features/bug fixes, I'd like to run both from one function/file.
Any suggestions/references on this flow would be greatly appreciated!
You can write your business logic in one function, that you call from the two Cloud Functions. Something along the following lines, with an asynchronous business logic and the use of async/await:
exports.myFunctionCalledFromTheApp = functions.https.onCall(async (data, context) => {
try {
const result = await asyncBusinessLogic();
return { result: result }
} catch (error) {
// ...
}
});
exports.myFunctionCalledByScheduler = functions.pubsub.schedule('every 24 hours').onRun(async (context) => {
try {
await asyncBusinessLogic();
return null;
} catch (error) {
// ...
return null;
}
});
async function asyncBusinessLogic() {
const result = await anAsynchronousJob();
return result;
}

await response of image upload before continue function

So I am working on a upload function for multiple images in an array. After a lot of struggling I have finally got my upload function to work and the images are showing up in the Firebase Database. However I have yet to find out a working way to make sure my upload function completes before continuing.
Below is the part were I am calling the upload function and try to store the response in uploadurl, the uploadurl variable is later used in the dispatch function to store the url with other data.
try {
uploadurl = await uploadImages()
address = await getAddress(selectedLocation)
console.log(uploadurl)
if (!uploadurl.lenght) {
Alert.alert('Upload error', 'Something went wrong uploading the photo, plase try again', [
{ text: 'Okay' }
]);
setIsLoading(true);
return;
}
dispatch(
So the image upload function is below. This works to the point that the images are uploaded, however the .then call to get the DownloadURL is not started correctly and the .then images also is not working.
uploadImages = () => {
const provider = firebase.database().ref(`providers/${uid}`);
let imagesArray = [];
try {
Promise.all(photos)
.then(photoarray => {
console.log('all responses are resolved succesfully')
for (let photo of photoarray) {
let file = photo.data;
const path = "Img_" + uuid.v4();
const ref = firebase
.storage()
.ref(`/${uid}/${path}`);
var metadata = {
contentType: 'image/jpeg',
};
ref.putString(file, 'base64', metadata).then(() => {
ref
.getDownloadURL()
.then(images => {
imagesArray.push({
uri: images
});
console.log("Out-imgArray", imagesArray);
})
})
};
return imagesArray
})
} catch (e) {
console.error(e);
}
};
So I want to return the imagesArray, AFTER, all the photos are uploaded. So the imagesArray is then set as uploadURL in the first function? After all images URL are set in imagesArray and passed to uploadURL, only then my dispatch function to upload the rest of the data should continue. How can I make sure this is happening as expected?
I have changed this so many times now because I keep getting send to different ways of doing this that I am completely at a loss how to continue now :(
Most of your uploadImages() code was correct, however in many places you didn't return the promise from each asynchronous action.
Quick sidestep: Handling many promises
When working with lots of asynchronous tasks based on an array, it is advised to map() the array to an array of Promises rather than use a for loop. This allows you to build an array of promises that can be fed to Promise.all() without the need to initialise and push to another array.
let arrayOfPromises = someArray.map((entry) => {
// do something with 'entry'
return somePromiseRelatedToEntry();
});
Promise.all(arrayOfPromises)
.then((resultsOfPromises) => {
console.log('All promises resolved successfully');
})
.catch((err) => {
// an error in one of the promises occurred
console.error(err);
})
The above snippet will fail if any of the contained promises fail. To silently ignore individual errors or defer them to handle later, you just add a catch() inside the mapped array step.
let arrayOfPromises = someArray.map((entry) => {
// do something with 'entry'
return somePromiseRelatedToEntry()
.catch(err => ({hasError: true, error: err})); // silently ignore errors for processing later
});
Updated uploadImages() code
Updating your code with these changes, gives the following result:
uploadImages = () => {
const provider = firebase.database().ref(`providers/${uid}`);
// CHANGED: removed 'let imagesArray = [];', no longer needed
return Promise.all(photos) // CHANGED: return the promise chain
.then(photoarray => {
console.log('all responses are resolved successfully');
// take each photo, upload it and then return it's download URL
return Promise.all(photoarray.map((photo) => { // CHANGED: used Promise.all(someArray.map(...)) idiom
let file = photo.data;
const path = "Img_" + uuid.v4();
const storageRef = firebase // CHANGED: renamed 'ref' to 'storageRef'
.storage()
.ref(`/${uid}/${path}`);
let metadata = {
contentType: 'image/jpeg',
};
// upload current photo and get it's download URL
return storageRef.putString(file, 'base64', metadata) // CHANGED: return the promise chain
.then(() => {
console.log(`${path} was uploaded successfully.`);
return storageRef.getDownloadURL() // CHANGED: return the promise chain
.then(fileUrl => ({uri: fileUrl}));
});
}));
})
.then((imagesArray) => { // These lines can
console.log("Out-imgArray: ", imagesArray) // safely be removed.
return imagesArray; // They are just
}) // for logging.
.catch((err) => {
console.error(err);
});
};

how can make synchronous promise in angular2

I am trying to call a function located in service class,and if that function returns data,one boolean variable sets true. I have 2 class as bollow:student.ts and service.ts:
// student.ts
public ngOnInit() {
this.config.load().then(() => {
this.service.getRecords().then(
function () { console.log("success getRecord");
this.loading = false; },
function () { console.log("failed getRecord");
this.loading = true; });
});
}
//service.ts
public getRecord(id: number): Promise<T> {
return this.getRecordImpl();
}
private getRecordsImpl(): Promise<T[]> {
let url = this.serviceUrl;
return this.http.get(url, this.getRequestOptionsWithToken())
.toPromise()
.then(res => {
this.records = this.extractData<T[]>(res);
for (var i = 0; i < this.records.length; i++) {
var record = this.records[i];
this.onRecord(record);
}
return this.records;
})
.catch(this.handleError);
}
by the now, records from service returns, but this.service.getRecords(); is undefined. and I can't use
.then
for handling succeed and failure actions.
I know that it is not good idea to make it synchronous. but think that being Asynchronous causes getRecords becomes undefined. What is the solution for handling that. I want it runs sequentially. and if service returns any records , variable initialize to false, otherwise it sets to true.
Many thanks for any help and guide.
I think your aproach is not correct, what is the point to make a promise synchronous ? If you really really want to do this I suggest you to dig in the Synchronous programming with es6 generators but usually the job is done much smother.
From your code I see that you are consuming your Promise by attaching .then() in the service. In this way you should create a new Promise.
private getRecordsImpl(): Promise<T[]> {
let url = this.serviceUrl;
return new Promise((resolve, reject) => {
this.http.get(url, this.getRequestOptionsWithToken())
.toPromise()
.then(res => {
this.records = this.extractData<T[]>(res);
for (var i = 0; i < this.records.length; i++) {
var record = this.records[i];
this.onRecord(record);
}
resolve(this.records);
})
.catch(this.handleError);
})
}
And in your code use:
this.service.getRecords().then(
function (records) { console.log("success getRecord");
this.loading = false; },
function (err) { console.log("failed getRecord");
this.loading = true; });

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