Mixin return values

[matthew-dean]

Can I set a return value as a color? As in:

.myselector {
   border: 1px solid .custommixin(@colorValue);
}

Just wondering in response to another user's issue regarding color functions: #488

[cloudhead]

Oh I see, no. But you can do..

.myselector () {
  @return: 2px;
}

.class {
  .myselector;
  border: @return solid red;
}

pretty ugly though.

[matthew-dean]

Ah, of course. It might be nice to have a returned value for custom color functions (and other custom value functions) when mixin guards are in place. @return could be a reserved variable for LESS. As you say, it's a bit ugly to just have a mixin do nothing but variable assignment when it's called.

Would be nicer to see the first example I posted supported at some point. The rationale being that you have spin, lighten, darken, etc functioning as built-in mixins, so the logic for return values is already there in LESS, it would just be opening up the door for custom mixins.

[matthew-dean]

Not I think that programming said functionality is easy mind you, just that it would empower people to extend the logic a bit.

[cloudhead]

yes, true, but I also like how it currently is, where the 'functions' are all javascript..

[jacobrask]

Couldn't variables accept arguments the same way mixins do? My usecase would be for instance:

@boxGlow(@spread: 5px, @color: #f00): inset 0 0 @spread @color;
.myselector {
   box-shadow: 1px 1px 1px #000, @boxGlow(2px, #00f);
}

It's also fairly analogous with JavaScript where functions live in regular variables.

[jacobrask]

@cloudhead: If I spent some time implementing that feature (I haven't looked at the Less source yet, so I can't promise anything), would you be willing to add it if the code is good enough?

[tylertate]

Adding a return capability to mixins would preserve the mapping of mixins to JavaScript functions, while still facilitating @jacobrask and @MatthewDL's use case. I've documented this a bit more on issue 637.

[lukeapage]

duplicate of #538

[lukeapage]

woops, this is #538

[akashivskyy]

This would be a very, very useful solution.

I'm trying to implement dynamically resizing images (like [UIImage resizable...] on iOS) and I would like to use a function which will return an URL string, not property/value pair.

Curently I'm using @cloudhead's solution.