Use reactiveCache for new features in v7.00 and newer

[mfilser]

There's coming a big PR with performance updates, especially to board and list loading.

I will add more informations here, especially for new "guidelines" for programming and data structure to make sure new features / PRs will also use the performance code.

[mfilser]

Here are some information regarding the performance commit for future development.

For database selection there's a new class, ReactiveCache in imports/reactiveCache.js.
Every database selection must be done with this class, except this places:

• server/migrations.js
• packages

If you need really need the database query and not an array set the parameter "getQuery" to true, e.g. at this commit: a533605.
This in only the case in some special situations, mostly with code working with the Meteor publication in server/publications/).

For combining database queries with an index search there's a new class ReactiveMiniMongoIndex.
For examples how to use it, have a look at the source code, e.g. here: ReactiveMiniMongoIndex.getChecklistItemsWithChecklistId
Using it at the right places can make many queries a lot faster.

[xet7]

That big PR from @mfilser where all of WeKan code has been made to use reactiveCache is here, it can also be looked for examples:

#5014