One efficient method to utilize data right away upon its retrieval from an HTTP request, without the need to iterate through each element in the

Question

One efficient method to utilize data right away upon its retrieval from an HTTP request, without the need to iterate through each element in the

While working in TypeScript, I encountered a scenario where I needed to loop through a list using a for loop and make an HTTP request for each array element to fetch its details. However, due to the time-consuming nature of this operation, I always ran into an error stating that there were no details available. Is there a way to process each detail immediately after it is returned from the HTTP request without waiting for the entire array loop to finish?

this.allAnalysisData.forEach((analysis) => {
        this.analysisCenterService.getAnalysisDetails(analysis.id).subscribe(detail => {
            this.detailed.push({Analysis: analysis, det: detail});
        });
    });

angular typescript rxjs

Answer 1

Answer №1

Avoid nesting your subscriptions within a forEach loop and vice versa. Utilize RxJS operators to their full potential, especially since Angular natively supports RxJS.

One option is to utilize forkJoin,

When all observables complete, emit the last emitted value from each.

The forkJoin() function will wait for the completion of the Array.forEach() loop before returning all the observables.

const observableList = [];

this.allAnalysisData.forEach((analysis) => {
  observableList.push(this.analysisCenterService.getAnalysisDetails(analysis.id));
});

forkJoin(observablesList).subscribe(response => {
  console.log(response);
  // handle any further logic
});

Answer 2

Avoid nesting your subscriptions within a forEach loop and vice versa. Utilize RxJS operators to their full potential, especially since Angular natively supports RxJS.

One option is to utilize forkJoin,

When all observables complete, emit the last emitted value from each.

The forkJoin() function will wait for the completion of the Array.forEach() loop before returning all the observables.

const observableList = [];

this.allAnalysisData.forEach((analysis) => {
  observableList.push(this.analysisCenterService.getAnalysisDetails(analysis.id));
});

forkJoin(observablesList).subscribe(response => {
  console.log(response);
  // handle any further logic
});

Answer 3

Answer №2

To await the result of your API call, you can utilize the async operator:

async fooFunction() 
{
    this.allAnalysisData.forEach((analysis) => {
        let detail= await this.analysisCenterService.getAnalysisDetails(analysis.id);
        this.detailed.push({Analysis:analysis , det:detail});
    });
}

If the return type of getAnalysisDetails is an Observable, you can convert it to a Promise using the .toPromise method:

 let result = await this.analysisCenterService.getAnalysisDetails(analysis.id).toPromise();

UPDATE:

According to the documentation on .toPromise:

The .toPromise method converts an Observable sequence to a Promise compliant with ES2015.

Answer 4

To await the result of your API call, you can utilize the async operator:

async fooFunction() 
{
    this.allAnalysisData.forEach((analysis) => {
        let detail= await this.analysisCenterService.getAnalysisDetails(analysis.id);
        this.detailed.push({Analysis:analysis , det:detail});
    });
}

If the return type of getAnalysisDetails is an Observable, you can convert it to a Promise using the .toPromise method:

 let result = await this.analysisCenterService.getAnalysisDetails(analysis.id).toPromise();

UPDATE:

According to the documentation on .toPromise:

The .toPromise method converts an Observable sequence to a Promise compliant with ES2015.

Answer 5

Answer №3

To utilize, simply execute the following code snippet: return forkJoin( this.allAnalysisData.map(analysis=> this._httpClient.get('url of services'+ analysis)) ).subscribes(response=> {});

Answer 6

To utilize, simply execute the following code snippet: return forkJoin( this.allAnalysisData.map(analysis=> this._httpClient.get('url of services'+ analysis)) ).subscribes(response=> {});

One efficient method to utilize data right away upon its retrieval from an HTTP request, without the need to iterate through each element in the

Answer №1

Answer №2

Answer №3

Similar questions

Form submission returns JSON data with an undefined value from the server

Resetting the Angular2 poller in an ng-bootstrap accordion

dts-gen encounters difficulties locating modules that are installed globally on the system

How can you save a CSV file to a temporary folder in Firebase Cloud Function using Puppeteer without a direct download link?

Tips for adjusting the dimensions of a child element to match its parent in Angular 12 with Typescript

Prevent form validation in ReactiveForm when a hidden field is present

Experiencing trouble accessing a property in TypeScript

An issue has occurred: Error - The specified NgModule is not a valid NgModule

Encountering an error in a map operation does not hinder the subsequent map operation from being carried out

Learn how to implement Angular 8 to listen for changes in an observable within an interceptor

What is the method for incorporating sorting into a mat-list?

The health check URL is experiencing issues: Unable to locate any routes

Update the mandatory fields in the required interface to extend to another interface, while ensuring that all subfields become

Leveraging multiple routes for a single component in Angular 6

Establish a local binding context within an Angular template

Access the JSON data containing sub array values and showcase them on an HTML page by utilizing ngFor

Troubleshoot: Angular5 Service call not functioning properly when called in ngOnInit

How can Angular effectively manage special characters such as umlauts?

Expanding a TypeScript type by creating an alias for a property

Instantly refreshing the Angular DOM following data modifications and retrieval from the database