Event "result" is not trigger on searchHelper

[exception0x876]

Hello,

I have a searchHelper function defined as following

filterSearchResults.prototype.searchHelper = function searchHelper(helper) {
  const that = this;
  helper.setIndex(this.indexName);
  helper.clearRefinements("category");
  if (this.facetFilters.category.length > 0) {
    helper.addFacetRefinement("category", this.facetFilters.category);
  }
  helper.clearRefinements("subcategories");
  if (this.facetFilters.subcategories.length > 0) {
    this.facetFilters.subcategories.forEach((subcategory) => {
      helper.addDisjunctiveFacetRefinement("subcategories", subcategory);
    });
  }
  helper.on("result", (results) => {
    console.log("here");
    that.checkAvailability(results);
  });
  helper.search();
};

The problem is that on('result') event is not triggered when the search is executed. However, I noticed that if I bind it to derived helper on('result') of mainHelper variable in InstantSearch.js the event is triggered just fine.

Is this expected behavior?

[Haroenv]

It looks like this isn't the complete implementation of your interface. In the context of InstantSearch relying directly on the helper interface for anything other than reading items of SearchResults and setting SearchParameters in getWidgetSearchParameters is not supported.

A bit of background: the search actually happens on derived helpers only in InstantSearch, as this allowed us to implement multi-index with less changes. The search method on the helper instance is overridden to have that behaviour

[anantakrishna]

In the context of InstantSearch relying directly on the helper interface for anything other than reading items of SearchResults and setting SearchParameters in getWidgetSearchParameters is not supported.

What about the example of an error-handling widget in the docs?

search.addWidgets([
  {
    init({ helper }) {
      helper.on('error', error => {
        console.error('Error', error);
      });
    }
  }
]);

This event callback is not triggered, and it is actually in line with your statement. I've even asked about this on the forum: https://discourse.algolia.com/t/error-handling-widget/13384.

But does it mean that this example in the docs is erroneous?

[Haroenv]

Yes, that example in the docs is wrong. Correct would be either:

search.addWidgets([
  {
    $$type: "error-display",
    render({ status, error }) {
      if (status === 'error' && error) {
        console.error('Error', error);
      }
    }
  }
]);

or

search.on('render', () => {
  const container = document.querySelector('#error-indicator');
  if (search.status === 'error') {
    container.innerText = search.error.message;
  } else {
    container.innerText = '';
  }
});

I've made a pull request to the docs to update that example, thanks @anantakrishna

[anantakrishna]

Thanks for updating the docs.

We're implementing and debugging an error widget now, and we've noticed that the render method of a widget is not called on an API error such as wrong API key, wrong index etc. Only when there is a network error (offline or wrong APP_ID). Whereas the render event is dispatched in both scenarios. Is it by design?

[Haroenv]

Ah yes that's right @anantakrishna, that's implemented this way as we don't have any widgets that require any change in rendering when an error happens today, so sending that render events for widgets was seen as overhead (and possibly a breaking change), so indeed only the event from InstantSearch can be used.

[anantakrishna]

Thanks for confirming! Though, why does the network error gets to the widgets then?

Anyhow, we're using the events but inside a custom widget, adding listeners in the init hook.