third_party/polymer/components-chromium/core-style/core-style.html

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   8 --><!--
   9
  10 The `core-style` element helps manage styling inside other elements and can
  11 be used to make themes. The `core-style` element can be either a producer
  12 or consumer of styling. If it has its `id` property set, it's a producer.
  13 Elements that are producers should include css styling as their text content.
  14 If a `core-style` has its `ref` property set, it's a consumer. A `core-style`
  15 typically sets its `ref` property to the value of the `id` property of the
  16 `core-style` it wants to use. This allows a single producer to be used in
  17 multiple places, for example, in many different elements.
  18
  19 It's common to place `core-style` producer elements inside HTMLImports.
  20 Remote stylesheets should be included this way, the &#64;import css mechanism is
  21 not currently supported.
  22
  23 Here's a basic example:
  24
  25     <polymer-element name="x-test" noscript>
  26       <template>
  27         <core-style ref="x-test"></core-style>
  28         <content></content>
  29       </template>
  30     </polymer-element>
  31
  32 The `x-test` element above will be styled by any `core-style` elements that have
  33 `id` set to `x-test`. These `core-style` producers are separate from the element
  34 definition, allowing a user of the element to style it independent of the author's
  35 styling. For example:
  36
  37     <core-style id="x-test">
  38       :host {
  39         backgound-color: steelblue;
  40       }
  41     </core-style>
  42
  43 The content of the `x-test` `core-style` producer gets included inside the
  44 shadowRoot of the `x-test` element. If the content of the `x-test` producer
  45 `core-style` changes, all consumers of it are automatically kept in sync. This
  46 allows updating styling on the fly.
  47
  48 The `core-style` element also supports bindings, in which case the producer
  49 `core-style` element is the model. Here's an example:
  50
  51     <core-style id="x-test">
  52       :host {
  53         background-color: {{myColor}};
  54       }
  55     </core-style>
  56     <script>
  57       document._currentScript.ownerDocument.getElementById('x-test').myColor = 'orange';
  58     </script>
  59
  60 Finally, to facilitate sharing data between `core-style` elements, all
  61 `core-style` elements have a `g` property which is set to the global
  62 `CoreStyle.g`. Here's an example:
  63
  64     <core-style id="x-test">
  65       :host {
  66         background-color: {{g.myColor}};
  67       }
  68     </core-style>
  69     <script>
  70       CoreStyle.g.myColor = 'tomato';
  71     </script>
  72
  73 Finally, one `core-style` can be nested inside another. The `core-style`
  74 element has a `list` property which is a map of all the `core-style` producers.
  75 A `core-style` producer's content is available via its `cssText` property.
  76 Putting this together:
  77
  78     <core-style id="common">
  79       :host {
  80         font-family: sans-serif;
  81       }
  82     </core-style>
  83
  84     <core-style id="x-test">
  85       {{list.common.cssText}}
  86
  87       :host {
  88         background-color: {{g.myColor}};
  89       }
  90     </core-style>
  91
  92
  93 @group Polymer Core Elements
  94 @element core-style
  95 @homepage github.io
  96 --><html><head><link rel="import" href="../polymer/polymer.html">
  97
  98 </head><body><polymer-element name="core-style" hidden="" assetpath="">
  99
 100 </polymer-element>
 101 <script charset="utf-8" src="core-style-extracted.js"></script></body></html>