feat(groupby): support for property getter function (allows property transformation).

[andryfailli]

Using a function you can group elements by a key derived from item properties. For example, you can apply a lowercase transformation to the team property.

Controller

vm.players = [
    {name: 'Gene', team: 'alpha'},
    {name: 'Andrea', team: 'Alpha'},
    {name: 'George', team: 'beta'},
    {name: 'Steve', team: 'gamma'},
    {name: 'Paula', team: 'beta'},
    {name: 'Scruath', team: 'gamma'}
];

vm.groupKeyGetterFunction = function(element) {
    return element.team.toLowerCase();
}

Temaplate

vm.players | groupBy:vm.groupKeyGetterFunction

[a8m]

Thanks for your contribution @andryfailli, but this capability already implemented. I created an example to demonstrate that - link.

I'm gonna close this PR, because it's irrelevant. Thanks!

[andryfailli]

Ouch! Ok...perfect. Maybe we can improve the documentation mentioning that a getter function can be used?

[a8m]

Maybe we can improve the documentation mentioning that a getter function can be used?

Sounds good. go for it 😃