chore(pagination): pageChanged triggered multiple times

[templth]

Hi all,

I open this issue following a question on StackOverflow. See http://stackoverflow.com/questions/35081261/ng2-bootstrap-pagination-pagechanged-triggered-multiple-times/.

We saw that the pageChanged event is fired three times at the initialization of the pagination component. We expected to have only one.

After investigating a bit, it's linked to the use of a TypeScript setter for the page property with a custom event. Because Angular2 fires events asynchronously (see this issue: angular/angular#6311), setting values to the page property fires event after the component initialization

We saw an inited property but it doesn't seem to be useful in this context...

We wonder if it's a normal behavior or a bug.

Here are some proposals to only have one events fired at the component startup:

(file node_modules/ng2-bootstrap/components/pagination/pagination.ts):

• Update the set page block to trigger events only when the inited property is true:

  public set page(value) {
    this._page = (value > this.totalPages) ? this.totalPages : (value || 1);
  
    if (this.inited) { // <---------------
      this.pageChanged.next({
        page: this._page,
        itemsPerPage: this.itemsPerPage
      });
    }
  }
  

• Update the ngOnInit method not to set the inited property to true at its end:

  ngOnInit() {
    (...)
    //this.inited = true;
  }
  

• Set the inited property to true at the end of the first call of the writeValue:

  writeValue(value:number) {
    this.page = value;
    this.pages = this.getPages(this.page, this.totalPages);
  
    if (!this.inited) {
      this.inited = true;
    }
  }
  

Thanks very much for your feedback!
Thierry

[krzysztofsaja]

Hi,
I've discovered this bug today as well. However, I believe that 'pageChanged' event shouldn't be fired even on component init but only if page is really changed. I've sent pull request for this bug.

Thanks,
Krzysztof

[templth]

Agreed! +1

Thanks very much!
Thierry