mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
Eventually we'll want to replace these with something fancier like polymer, but this exercise helped us find several bugs in the engine as well as removed one more blocker from using Sky to replace mojo/views usage in mojo/examples. R=esprehn@chromium.org BUG=443439 Review URL: https://codereview.chromium.org/809233002
SkyElement
SkyElement is the framework for creating...yup...Sky Elements. It take heavy inspriation from Polymer and isn't very fully featured...yet
Declaring an element
<import src="../path/to/sky-element.sky" as="SkyElement" />
<template>
<my-other-element>Hello, {{ place }}</my-other-element>
</template>
<script>
// SkyElement takes a single object as it's only parameter
SkyElement({
name: 'my-element', // required. The element's tag-name
attached: function() {
this.place = 'World';
}, // optional
detached: function() {}, // optional
attributeChanged: function(attrName, newValue, oldValue) {} // optional
});
</script>
Note that an element's declared ShadowDOM is the previous <template>
element to the <script> element which defines the element.
Databinding
SkyElement's databinding support is derived from Polymer's. At the moment, there are some key differences:
There is not yet support for
- Declarative event handlers
- Inline expressions
- Self-observation (e.g.
fooChanged()gets invoked whenthis.foois changed) - Computed properties (e.g. the computed block)
- Conditional attributes (e.g.
<my-foo checked?="{{ val }}")
Also, because there are so few built-in elements in Sky, the default behavior of HTMLElement with bindings is to assign to the property. e.g.
<my-foo bar="{{ bas }}">
Will not setAttribute on the my-foo, instead it will assign to the bar
property of my-foo. There are two exceptions to this: class & style --
those stillsetAttribute.