No 'Access-Control-Allow-Origin' header is present: ionic 3 Ask


#1

This is my provider file from ionic

getJobDetails() {
    if(this.data) {
      return Promise.resolve(this.data);
    }
    return new Promise(resolve =>{
      let headers = new Headers();
      headers.append('Content-Type','application/json');
      this.http.get('http://localhost:3000/api/jobdetail',{headers: headers})
      .map(res => res.json())
      .subscribe(data => {
        this.data = data;
        resolve(this.data);
      });
    });
  }

below is the code where I’m trying to print the data in console log

constructor(public jobdetail: JobsDataProvider)    
ionViewDidLoad() {

        this.jobdetail.getJobDetails().then((data) => {
          console.log(data);
          this.jdetails = data;
        });
      }

why I’m getting the error as after passing the headers.

Failed to load http://localhost:3000/api/jobdetail: Response to preflight request doesn’t pass access control check: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘http://localhost:8100’ is therefore not allowed access. Response {_body: ProgressEvent, status: 0, ok: false, statusText: “”, headers: Headers, …} headers : Headers {_headers: Map(0), _normalizedNames: Map(0)} ok : false status : 0 statusText : “” type : 3 url : null _body : ProgressEvent {isTrusted: true, lengthComputable: false, loaded: 0, total: 0, type: “error”, …} proto : Body


#2

The issue is on the backend.