159 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			159 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| # PostCSS Discard Overridden
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| 
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| [PostCSS] plugin to discard overridden `@keyframes` or `@counter-style`.
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| 
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| `@keyframes` or `@counter-style` will be overridden by those who share the same identifiers and appear later in stylesheets. So we can discard all of them except the last one. When defined inside a `@media` or `@supports` rule, `@keyframes` and `@counter-style` rules only override global rules in some of the client browsers so they need handled separately. This plugin has taken care of this and transforms the PostCss AST **safely**.
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| 
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| [PostCSS]: https://github.com/postcss/postcss
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| 
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| ```css
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| @-webkit-keyframes fade-in {
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|   0% {
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|     opacity: 0;
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|   }
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|   100% {
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|     opacity: 0.8;
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|   }
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| }
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| @keyframes fade-in {
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|   0% {
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|     opacity: 0;
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|   }
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|   100% {
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|     opacity: 0.8;
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|   }
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| }
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| @media (max-width: 500px) {
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|   @-webkit-keyframes fade-in {
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|     0% {
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|       opacity: 0;
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|     }
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|     100% {
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|       opacity: 1;
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|     }
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|   }
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|   @keyframes fade-in {
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|     0% {
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|       opacity: 0;
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|     }
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|     100% {
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|       opacity: 1;
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|     }
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|   }
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|   @-webkit-keyframes fade-in {
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|     0% {
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|       opacity: 0;
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|     }
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|     100% {
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|       opacity: 0.8;
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|     }
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|   }
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|   @keyframes fade-in {
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|     0% {
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|       opacity: 0;
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|     }
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|     100% {
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|       opacity: 0.8;
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|     }
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|   }
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|   @supports (display: flex) {
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|     @-webkit-keyframes fade-in {
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|       0% {
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|         opacity: 0;
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|       }
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|       100% {
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|         opacity: 1;
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|       }
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|     }
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|     @keyframes fade-in {
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|       0% {
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|         opacity: 0;
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|       }
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|       100% {
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|         opacity: 1;
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|       }
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|     }
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|   }
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| }
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| @-webkit-keyframes fade-in {
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|   0% {
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|     opacity: 0;
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|   }
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|   100% {
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|     opacity: 1;
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|   }
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| }
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| @keyframes fade-in {
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|   0% {
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|     opacity: 0;
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|   }
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|   100% {
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|     opacity: 1;
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|   }
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| }
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| ```
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| 
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| ```css
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| @media (max-width: 500px) {
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|   @-webkit-keyframes fade-in {
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|     0% {
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|       opacity: 0;
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|     }
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|     100% {
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|       opacity: 0.8;
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|     }
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|   }
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|   @keyframes fade-in {
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|     0% {
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|       opacity: 0;
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|     }
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|     100% {
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|       opacity: 0.8;
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|     }
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|   }
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|   @supports (display: flex) {
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|     @-webkit-keyframes fade-in {
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|       0% {
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|         opacity: 0;
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|       }
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|       100% {
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|         opacity: 1;
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|       }
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|     }
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|     @keyframes fade-in {
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|       0% {
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|         opacity: 0;
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|       }
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|       100% {
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|         opacity: 1;
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|       }
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|     }
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|   }
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| }
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| @-webkit-keyframes fade-in {
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|   0% {
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|     opacity: 0;
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|   }
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|   100% {
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|     opacity: 1;
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|   }
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| }
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| @keyframes fade-in {
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|   0% {
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|     opacity: 0;
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|   }
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|   100% {
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|     opacity: 1;
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|   }
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| }
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| ```
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| 
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| ## Usage
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| 
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| See the [PostCSS documentation](https://github.com/postcss/postcss#usage) for
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| examples for your environment.
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| 
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| ## Contributors
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| 
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| See [CONTRIBUTORS.md](https://github.com/cssnano/cssnano/blob/master/CONTRIBUTORS.md).
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