During the frontend rewrite, we introduced mithril patches for a `route` attr, and for `m.stream`. Later, we decided not to go that route, but not to remove the patches yet to avoid breaking extensions while we were finalizing the replacements. We can now remove these.
Other BC layers are for things from before beta 14, so those remain in place.
- Use Mithril.Attributes as base for ComponentAttrs, remove =any from class signature for Component
- Convert Alert to TypeScript, introduce AlertAttrs interface
- Convert AlertManagerState to TypeScript, add overload signatures for `show`, introduce AlertState interface for stored Alerts.
- Set ComponentAttrs as default T for Component
- Make attrs in AlertAttrs optional
- Add AlertIdentifier interface, simplify show type signature
- Remove mithril patch shim, as all patches onto m are now deprecated
- Use Mithril.Static for shim
- Ensure that the discussion list is cleared before it is updated with fetched results
- Rename `clear` to `deferClear`, improve documentation to make its purpose clearer.
- Call onNewRoute when page changed with same component in DiscussionPage and UserPage
- Make app.previous and app.current changed in onNewRoute, not in oninit. This way, when the route is changed, but still handled by the same component, a new PageState object will still be created.
While more pleasant from an FSM standpoint, comparing the current targetPost to the previous one does not work if goToNumber is called twice in a row for the same post. For instance, if a user clicks the mentions link to a post twice, the post stream breaks.
In some cases, such as if we've stickied a post, an event post
may have been added / removed.This means that `this.visibleEnd`
and`this.count()` will be out of sync by 1 post, but we are still
"viewing the end" of the post stream, so we should still reload
all posts up until the last one.
Because the Slidable class was always added on creation, it was lost every time the class list changed (in this case when the discussion was hidden/unhidden which added/removed DiscussionListItem--hidden class). So by determining the Slidable class's presence in elementAttrs() method, it guarantees it always properly set.
