How to use CSS mixins with Angular 2, Dart and Polymer

问题

I'm using polymer and polymer_elements in my angular2-dart project.

I'm able to add polymer elements (such as paper-card), but I'm not able to use css-mixins, I don't know if I missing an import or something.

My .dart

import 'package:angular2/core.dart';
//Polymer imports
import 'package:polymer_elements/paper_card.dart';
import 'package:polymer_elements/paper_button.dart';
import 'package:polymer_elements/paper_icon_button.dart';
import 'package:polymer_elements/iron_icon.dart';
import 'package:polymer_elements/paper_styles/classes/typography.dart';
import 'package:polymer_elements/iron_flex_layout/classes/iron_flex_layout.dart';

@Component(
    templateUrl: '../view/book_splash_component.html',
    selector: 'book-splash',
    styleUrls: const ['../view/css/book_splash_component.css'],
    encapsulation: ViewEncapsulation.Native
)
class BookSplashComponent{
    //nothing that matters
}

My .html

<paper-card class="rate">
    <div class="rate-content">
        <div class="card-content">
            <div class="rate-header">Rate this album</div>
            <div class="rate-name">Mac Miller</div>
            <div>Live from space</div>
        </div>
        <div class="card-actions">
            <paper-icon-button class="rate-icon" icon="star"></paper-icon-button>
        </div>
    </div>
    <div class="rate-image"></div>
</paper-card>

My .css with mixins (which doesn't work)

paper-card.rate { @apply(--layout-horizontal); }
  .rate-image {
    width: 100px;
    height: 170px;
    background: url('./donuts.png');
    background-size: cover;
  }
  .rate-content {
    @apply(--layout-flex);
    float: left;
  }
  .rate-header { @apply(--paper-font-headline); }
  .rate-name { color: var(--paper-grey-600); margin: 10px 0; }
  paper-icon-button.rate-icon {
    --iron-icon-fill-color: white;
    --iron-icon-stroke-color: var(--paper-grey-600);
  }

But if I replace mixins with the corresponding styles it works! Probably I'm missing something stupid.

I'm trying "Paper-cards can have a horizontal image" example here: https://elements.polymer-project.org/elements/paper-card?active=paper-card&view=demo:demo/index.html

回答1:

Did you try to play with shadow dom, like disable it in your angular component or on polymer to see what happen ?

回答2:

This is Polymer specific and works only in the style tag of a Polymer element or in a <style is="custom-style"> in the head element.

来源：https://stackoverflow.com/questions/37490068/how-to-use-css-mixins-with-angular-2-dart-and-polymer