Adding language change broadcast

[gjn]

This adresses #173

The Language directive now broadcasts a gaLanguageChange message
that other controllers/directives can listen to. This allows
directive that rely on outside source which are language
dependant to reload their resources. This is needed because
our services deliver translated things (like catalog entries,
layer names, etc) which are not translated on the client.

The only directive now depending on this is the
backgroundlayerselector. Before this, the language in the combobox
didn't change. Now it does.

[elemoine]

The $translate service already broadcasts translationChange events when switching languages. I think we should use that instead of having our gaTranslationSelector directive broadcast a custom event.

Also, it is to be noted that events broadcasted on the $rootScope are by definition very global. So we need to make sure that they actually correspond to global, application-level, state changes.

[elemoine]

So the background layer directive now listens to gaTopicChange and gaLanguageChange events. This sounds like too much responsibility on the background layer directive (and other directives that will rely on the gaLayers service in the future). It does not make sense to me that the background layer directive must know that the layers must be loaded again when the language changes. That's knowledge the background layer directive need not have.

And the reloadTopic function looks hackish to me. Also, I don't think that its name actually captures the action it performs. The gaLayers service doesn't load topics, it loads layers.

Anyway, that suggests to me that a better design should be found.

Here's something I'd try: the gaLayers service itself, instead of the background layer directive, listens to gaTopicChange and gaLanguageChange events. And when such an event occurs the gaLayers service naturally loads new layers from the layersconfig service. And one new layers have been loaded it broadcasts a gaLayersChange event. Directives like the background layer directive just listen to gaLayersChange events. So they no longer need to know that the topic or language has changed, they just react on "layers changed" events, which is the only thing they need to know really. And with that design gaLayers.getBackgroundLayers and friends can even directly return the expected data directly instead of a promise.

This obviously would need to be implemented to know if that actually works.

[cedricmoullet]

I agree with Eric's point of view.

[loicgasser]

+1
Le 28 juil. 2013 16:24, "Cédric Moullet" notifications@github.com a
écrit :

In
src/components/backgroundlayerselector/BackgroundLayerSelectorDirective.js:

•         scope.$on('gaLanguageChange', function() {
  

•           gaLayers.reloadTopic();
  

•           onTriggeredChange();
        });
  

I agree with Eric's point of view.

—
Reply to this email directly or view it on GitHubhttps://github.com//pull/174/files#r5440114
.