nothing happens when i submit a form in MEAN STACK

so the project is so simple. the user inputs some infos about a book and click submit to save the infos in a database (Mongodb) i’m using MEAN STACK and i’m a noobie (obviously). nothing happens when i submit not even an error.

backend code :

    //POST ONE BOOK
    booksRoute.route('/post').post((req,res,next)=>{
        var x = {
            name   : req.params.name,
            genre  : req.params.genre,   
            author : req.params.author,
            rating : req.params.rating,
            price  : req.params.price
        }
        console.log(x) ; 
        BookModel(x).save((err,data)=>{
            if (err){console.log(err);}
            else res.send(data) ;
}) ;
})

add book component html :

<ul>
    <form #f="ngForm" (ngSubmit)="onSubmit(f)">  
    <li>
    <label>book's name *</label>
    <input name="name" type="text" ngModel>
    </li>
    <li>
    <label>book's genre *</label>
    <input name="genre" type="text" ngModel>
    </li>
    <li>
    <label>book's author *</label>
    <input name="author" type="text" ngModel>
    </li>
    <li>
    <label>rating *</label>
    <input name="rating" type="number" [max]="10" min="0" ngModel>
    </li>
    <li>
    <label>price *</label>
    <input name="price" type="number" ngModel>
    <input class="btn btn-primary" type="submit"/> 
    </li>  
</form>
</ul>

angular service

  postBook(data){
    console.log(data) ;
    return this.http.post(this.backendUrl+'/post',data) ;
  }

in addBook component ts

onSubmit(f){
    //console.log(f.value) ;
    this.apiService.postBook(f.value) ; 
  }

Note : i can get data from the database, i can find a book by it’s name but i can’t post

>Solution :

I guess that You need to subscribe to the response of your API/back, something like this:

onSubmit(f){
    //console.log(f.value) ;
    this.apiService.postBook(f.value)
    .subscribe( res => {
     console.log('The back response:', res);
    }); 
}

Until you don’t subscribe to the observable which has the http call to the API, is not going to "start" the http call process.