Now instead of calling addEventListener inside the created() callback you just
add on-{eventName} attributes to the <sky-element> around your element
definition. The attribute defines what method on your element to call when the
event with {eventName} is dispatched through your element.
Implementing this required refactoring how sky-element.sky stored information
from each registered element. Now instead of storing just a map of templates
we store a map of ElementRegistration objects which have metadata about the
element. Future patches will combine this system with the element registration
system in sky-binder.
R=ojan@chromium.org
Review URL: https://codereview.chromium.org/845283003
Now you can use the attributes attribute on <sky-element> that
accepts a set of name:type comma separated pairs to control
the reflected attributes. ex. attributes="size:number"
Each attribute creates a getter and a setter on the element that returns
the correct type and will coerce the string attribute values into the
right type. It also correctly hooks into the data binding system.
A new callback is added: {name}Changed(oldValue, newValue) which will
be invoked whenever the attribute with that name changes and gets the
correctly coerced type values. See the <sky-radio> or <sky-checkbox>
widgets for examples of using the new callback.
Number attributes default to 0, booleans to false, and strings to empty
string. There is no way provided to set a different default, for that you
can use hasAttribute in the created callback to conditionally set a value.
Don't just assign the property there otherwise you'll overwrite the value
from the parser.
Another behavior change from making this work is that now attributeChanged()
is called for each attribute, even when the element is created by the
parser.
Overall this allows a nice simplification to the <sky-button>,
<sky-radio> and <sky-checkbox> widgets.
R=abarth@chromium.org
Review URL: https://codereview.chromium.org/836923002
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
