Identify "Data Context" in Amphora Locals

[yuliyv]

Currently the locals parameter passed to component render hooks looks something like this:

{
  "user": {  },
  "url": "SITE_PREFIX/YYYY/MM/article-slug.html",
  "site": {  },
  "routes": [ ],
  "components": [],
  "params": {
    "year": "YYYY",
     "month": "MM",
     "name": "article-slug.html"
  },
  "query": {},
  "extension": "html"
}

If we render the exact same component using a different renderer then the data would be almost identical except the url, params, and extension might change. This poses a challenge when we have complex component which need to identify page data that is not available at the component level. The current strategy is to utilize locals.url as a key to uniquely identify the data context for a render, however, since the same component might be rendered on different URLs this is not sufficiently unique to identify the data context for a render event.

To alleviate this issue there should be some attribute into the locals that can consistently determine what the context of our render., a simple example might be that any time we pass through url to the locals we should also pass through pageUri or something else which is unique in Amphora.