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Issue 18354007:
initial commit of shadow_dom pkg (Closed)
Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart| Index: pkg/shadow_dom/README.md |
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| +# Shadow DOM polyfill |
| + |
| +Shadow DOM is designed to provide encapsulation by hiding DOM subtrees under |
|
Jennifer Messerly
2013/07/10 01:15:30
this text is from www.polymer-project.org/platform
|
| +shadow roots. It provides a method of establishing and maintaining functional |
| +boundaries between DOM trees and how these trees interact with each other within |
| +a document, thus enabling better functional encapsulation within the DOM. See |
| +the |
| +[W3C specification](https://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html) |
| +for details. |
| + |
| +## Getting started |
| + |
| +Include the polyfill in your HTML `<head>` to enable Shadow DOM: |
|
Jennifer Messerly
2013/07/10 01:15:30
I added this section to illustrate usage.
dgrove
2013/07/10 20:04:32
Is there a way to avoid downloading the JS polyfil
Jennifer Messerly
2013/07/10 20:25:03
probably yes. It looks like https://github.com/Pol
|
| + |
| +```html |
| + <script src="packages/shadow_dom/shadow_dom.debug.js"></script> |
| +``` |
| + |
| +You can also use a minified version for deployment: |
| + |
| +```html |
| + <script src="packages/shadow_dom/shadow_dom.min.js"></script> |
| +``` |
| + |
| +Because it does extensive DOM patching, it should be included before other |
|
Siggi Cherem (dart-lang)
2013/07/10 15:45:08
suggestion: make bold **before** or **before other
Jennifer Messerly
2013/07/10 20:25:03
Done.
|
| +script tags. |
| + |
| +## Useful Resources |
|
Jennifer Messerly
2013/07/10 01:15:30
from www.polymer-project.org/platform/shadow-dom.h
|
| + |
| +- [What the Heck is Shadow DOM?](http://glazkov.com/2011/01/14/what-the-heck-is-shadow-dom/) |
| +- [Web Components Explained - Shadow DOM](https://dvcs.w3.org/hg/webcomponents/raw-file/57f8cfc4a7dc/explainer/index.html#shadow-dom-section) |
| +- [HTML5Rocks - Shadow DOM 101](http://www.html5rocks.com/tutorials/webcomponents/shadowdom/) |
| +- [HTML5Rocks - Shadow DOM 201: CSS and Styling](http://www.html5rocks.com/tutorials/webcomponents/shadowdom-201/) |
| +- [HTML5Rocks - Shadow DOM 301: Advanced Concepts & DOM APIs](http://www.html5rocks.com/tutorials/webcomponents/shadowdom-301/) |
| + |
| +## Learn the tech |
| + |
| +### Basic usage |
| + |
| +```dart |
|
Jennifer Messerly
2013/07/10 01:15:30
fixed this to be Dart
|
| +var el = new DivElement(); |
| +var shadow = el.createShadowRoot(); |
| +shadow.innerHtml = '<content select="h1"></content>'; |
| +``` |
| + |
| +### Shadow DOM subtrees |
| + |
| +Shadow DOM allows a single node to express three subtrees: _light DOM_, _shadow DOM_, and _composed DOM_. |
| + |
| +A component user supplies the light DOM; the node has a (hidden) shadow DOM; and the composed DOM is what is actually rendered in the browser. At render time, the light DOM is merged with the shadow DOM to produce the composed DOM. For example: |
| + |
| +**Light DOM** |
| + |
| +```html |
| +<my-custom-element> |
| + <!-- everything in here is my-custom-element's light DOM --> |
| + <q>Hello World</q> |
| +</my-custom-element> |
| +``` |
| + |
| +**Shadow DOM** |
| + |
| +```html |
| +<!-- shadow-root is attached to my-custom-element, but is not a child --> |
| +<shadow-root> |
| + <!-- everything in here is my-custom-element's shadow DOM --> |
| + <span>People say: <content></content></span> |
| +</shadow-root> |
| +``` |
| + |
| +**Composed (rendered) DOM** |
| + |
| +```html |
| +<!-- rendered DOM --> |
| +<my-custom-element> |
| + <span>People say: <q>Hello World</q></span> |
| +</my-custom-element> |
| +``` |
| + |
| +The following is true about this example: |
| + |
| +* The light DOM that belongs to `<my-custom-element>` is visible to the user as its normal subtree. It can expressed by `.childNodes`, `.nodes`, `.innerHtml` or any other property or method that gives you information about a node's subtree. |
| +* Nodes in light DOM or shadow DOM express parent and sibling relationships that match their respective tree structures; the relationships that exist in the rendered tree are not expressed anywhere in DOM. |
| + |
| +So, while in the final rendered tree `<span>` is a child of `<my-custom-element>` and the parent of `<q>`, interrogating those nodes will tell you that the `<span>` is a child of `<shadow-root>` and `<q>` is a child of `<my-custom-element>`, and that those two nodes are unrelated. |
| + |
| +In this way, the user can manipulate light DOM or shadow DOM directly as regular DOM subtrees, and let the system take care of keeping the render tree synchronized. |
| + |
| +## Polyfill details |
| + |
| +You can read more about how the polyfill is implemented in JavaScript here: |
| +<https://github.com/polymer/ShadowDOM#polyfill-details>. |
| + |
| +## Getting the source code |
|
Jennifer Messerly
2013/07/10 01:15:30
this info indicates how to get the code and build
|
| + |
| +This package is built from: |
| +<https://github.com/dart-lang/ShadowDOM/tree/conditional_shadowdom> |
| + |
| +You'll need [node.js](http://nodejs.org) to rebuild the JS file. Use `npm install` to |
| +get dependencies and `grunt` to build. |
