Allowing others to make new projections

[sunesimonsen]

It would be very nice if I were able to provide new projections without forking your project. The only thing that is holding me back from doing this, is that I want my projections to be chainable with the existing projections. Right now there is a global cache of projections that is used to add the methods to the returned projection:

ko[projectionFunctionsCacheName] = {
    map: ...
    filter: ...
};

It would be nice if this cache was public - maybe use ko.projections for the cache instead of saving the exclusion marker there. It would also be required that the projection cache is not overwritten if it already exist.

ko.projections = ko.extend(ko.projections || {}, {
    map: ...
    filter: ...
});

[sunesimonsen]

@SteveSanderson: It is a bit of time since I posted this issue, I know you are extremely busy with the great work you doing on Knockout, but I would be greatly appreciated if you could give your feedback on this issue. Otherwise we will probably continue our fork in a direction that is not compatible with the upstream repository, and that would be a bit sad.

Kind regards Sune