Using a variable in a mixin call

[vrbvillor]

Such as

.lt(){
    left:0;
    top:0;
}

when I use a variable

@n : lt;
.@{n}();

The second line of the second passage of code, I want to call the .lt(). How to realize it? THANKS.

[seven-phases-max]

Currently it's impossible to call a mixin indirectly (i.e. by name as variable value).
However depending on your specific use-case there're several nearly equal methods to achieve indirect calls.

---

(The feature itself was proposed among other variations in #965 (comment). But since #965 itself is closed because its initial idea (DRs) is implement I suppose this one needs a dedicated ticket. So I'm not closing this one yet (but eventually it's most likely to be replaced by one with more detailed info).

[matthew-dean]

This would be a short-term fix.

@lt: {
    left:0;
    top:0;
};
@n : lt;
@x : @@n;
@x();

And if you have multiple matching .lt mixins, you can "wrap" your mixin in a detached ruleset to get the same effect (e.g.):

@lt: { .lt() };
.lt() {
    left:0;
    top:0;
}
.lt() {
    color: red;
}
rules {
    @n : lt;
    @x : @@n;
    @x();
}

// this will output
rules {
  left: 0;
  top: 0;
  color: red;
}

Unfortunately, there's an existing issue that prevents you from calling @@n() directly, but it's a short workaround.

[seven-phases-max]

That's all too verbose. Old-school methods may result in a more compact workaround (though I'm intentionally not providing any in this case since it would be pretty useless w/o knowing the actual use-case/context (i.e. why exactly n is a variable). Otherwise it's not clear how it would be different from just :

.lt() {
    left: 0;
    top:  0;
}

.n() {.lt}
.n();

// or:

@n: {.lt}
@n();

[vrbvillor]

@matthew-dean @seven-phases-max Thanks to you all, I'll try them. and by the way, the script below can't compile succesfully, what's wrong with it ?

.clouds(){
    0% {
        .l(-20%);
        .opacity(.8);
    }
    50%{
        .l(50%);
        .opacity(.7);
    }
    100%{
        .l(120%);
        .opacity(.7);
    }
}

.keyframes(@name,@mixin){
    @keyframes @name{
        @mixin();
    }
    @-webkit-keyframes @name{
        @mixin();
    }
}
.keyframes(cloud,.clouds());

It says "Syntax error expected ')' got '.' in (filename) on line 92, column 18:

91 }
92 .keyframes(cloud,.clouds());
93

How to use a mixin as a parameter?? Thanks...

[vrbvillor]

I've resolved myself........

[seven-phases-max]

Closing as N/A anymore.
For vendor-prefixing use Autoprefixer. For more advanced stuff see for example
http://stackoverflow.com/questions/23462155/dynamic-prefixed-keyframe-generation-with-less-css/23464685#23464685
http://stackoverflow.com/questions/29142854/less-mixin-to-create-blink-animation-passing-color-stops/29148073#29148073
etc.