Mixin delegates

[kreopt]

Not sure if this feature is not implemented, but i don't find the way to do this and issues creaded earlier.

I'd like to write some generic mixins taking other mixins as parameters such this:

.clickable(@hoverEffect, @activeEffect){
   &:hover{.@{hoverEffect}();}
   &:active{.@{activeEffect}();}
}

.active_delegate(){background:#aaa;/* something more complicated here...*/}
.hover_delegate(){background:#ddd;/*...*/}
.active_delegate--dark(){background:#666;/*...*/}
.hover_delegate--dark(){background:#333;/*...*/}

.button{
  background: #fff;
  .clickable(hover_delegate, active_delegate);
}

.button--dark{
  background:#000;
  .clickable(hover_delegate--dark, active_delegate--dark);
}

[seven-phases-max]

See #965 (and closely related discussion started at #1648 (comment)). Well, no, you can't call a mixin like that: .@{hoverEffect}();. The goal can be achieved with "detached rulesets" though, e.g.:

.clickable(@hoverEffect, @activeEffect) {
    &:hover  {@hoverEffect();}
    &:active {@activeEffect();}
}

@active_delegate:       {background: #aaa};
@hover_delegate:        {background: #ddd};
@active_delegate--dark: {background: #666};
@hover_delegate--dark:  {background: #333};

.button {
    background: #fff;
   .clickable(@hover_delegate, @active_delegate);
}

.button--dark {
    background: #000;
   .clickable(@hover_delegate--dark, @active_delegate--dark);
}

And if you still need those delegates to be available as mixins you can wrap them into DRs right at the point of passing into .clickable as parameters:

.clickable(@hoverEffect, @activeEffect) {
    &:hover  {@hoverEffect();}
    &:active {@activeEffect();}
}

.active_delegate()       {background: #aaa}
.hover_delegate()        {background: #ddd}
.active_delegate--dark() {background: #666}
.hover_delegate--dark()  {background: #333}

.button {
    background: #fff;
   .clickable({.hover_delegate}, {.active_delegate});
}

.button--dark {
    background: #000;
   .clickable({.hover_delegate--dark}, {.active_delegate--dark});
}

Alternatively you can use "tagged callbacks" (which are quite more verbose but may have their pros in certain more advanced cases, for instance when you need a delegate with parameters - this is what the "detached ruleset" is incapable of, at least directly (yet)).

[seven-phases-max]

Closing as duplicate of #965.

[kreopt]

Thanks. It is actually what I want