How to set a variable in another angular 2 component -

i'm building angular 4 application , have 2 separate pages, detail page , edit page, each own component.

when user edits model on edit page, redirect them details page this:

// within retailereditcomponent save(): void {     this.retailerservice.updateretailer(this.retailer)         .then(() => this.router.navigate(['/admin/retailer'])); } 

in admin/retailer page, have retailerdetailcomponent looks this:

export class retailerdetailcomponent {     retailer: retailer;      public hasbeenupdated: boolean = false;      constructor(         private retailerservice: retailerservice,     ) {         console.log("in retailerdetailcomponent");     }  } 

how can set bool hasbeenupdated true other page?

update:

i idea of eventemitter, running problems.

my retailerservice:

export class retailerservice {     public onretailerupdated = new eventemitter();;      updateretailer(retailer: retailer): promise<retailer> {         this.onretailerupdated.next(true);         return new promise((resolve, reject) => {             apigclient.retailervput({}, retailer, {})                 .then(function (result) {                                                   resolve(result.data[0])                  }).catch(function (result) {                       reject(result)                  });                 }             })          });     }  } 

and in retailerdetailcomponent:

export class retailerdetailcomponent implements loggedincallback { retailer: retailer;

public showerror: boolean;  constructor(     private retailerservice: retailerservice) {  } ngoninit(): void {     this.retailerservice          .onretailerupdated          .subscribe(value => {               this.showerror = true;             console.log('event thingy worked')         }); } 

but console message doesn't show up

the best way use subscription eventemitter. example below:

1. you can define event emitter in retailer service:

public onretailerupdated = new eventemitter< boolean >();

2. then, in "updateretailer" method, add line:

this.onretailerupdated.next(true);

3. subcribe event in retailerdetailcomponent:

this.retailerservice .onretailerupdated .subscribe(value => { // perform appropriate action here });

private subscription;  ngoninit() {       this.subscription = this.retailerservice.onretailerupdated                             .subscribe(value => {                                // perform appropriate action here      });  };  ngondestroy() {      this.subscription.unsubscribe();  };