Load morphology data from URL

[manuelaugustin]

For Premium, we need to load morphology data from MyYoast. For this, we need to add functionality that loads a JSON file from a URL. This request should return the a 200 with the JSON file when it succeeds and a 403 with an error message in case it fails.

For testing purposes, we can load the file from the YoastSEO.js-premium-configuration repo.

[igorschoester]

Premium JS

• Query MyYoast for the JSON file (URL will probably be this: https://my.yoast.com/api/Downloads/file/morphology-list?site=BASE_URL).
• Handle any responses. On error the user needs to get a message stating what happend.
  • 401 placeholder: Hey, it looks like you haven't activated WordPresss SEO Premium on my.yoast.com! This means you currently don't have access to premium features like our morphology analysis! You can read more about activating your site here ( KB link ).
• On success, the morphology object should get passed to the worker, via initialize. Pass the morphology data like so: researchData: { morphology: DATA }.

YoastSEO.js

• Rename researcher.addResearchDataProvider to researcher.addResearchData. The provider should be a function and that can not be passed like this. The provider part will not get implemented yet, for now we handle the data directly.
• The worker.initialize needs to listen to the researchData key and call addResearchData on the researcher.

[hansjovis]

@hedgefield / @uxkai : When the loading of morphology data fails, for example when the site is not registered with MyYoast yet, the user should get an error message (see @igorschoester 's comment above). What would the best place to show this error message be?