Collapsiblepanelextender prevents updating
This allows us to easily write components that meet the Content Changes requirement on the Gold Standard checklist for web components.
Step 2: Drag and drop a Script Manager and an Update Panel to the page.Each mixin had to not only declare the attributes it cared about, but it had to cooperatively construct the final array.We eventually hit on the idea of having the aforementioned Attribute Marshalling mixin programmatically inspect the component class for all custom properties, and automatically generate an appropriate array of attributes for .The creator of the component would like to be able to write a property getter/setter that reflects its state as CSS classes: return an element with default attributes.Overall, we’re excited that we’ve got our components and mixins working in production Chrome 54, which just shipped last week with support for both Shadow DOM v1 and Custom Elements v1.The v0 features that were dropped were ones we had never used (multiple shadow roots, shadow-piercing CSS combinators) or had avoided (), so their absence in v1 did not present a problem.One v1 feature that we had heavily lobbied for was the addition of the slotchange event.The intention, as we understand it, is to mirror standard element behavior. In practice, it introduces complications because a web app author that instantiates a component would like to be able to immediately make changes to it before adding it to the document. The result will likely be components that belatedly apply default attributes, stomping on top of attributes that were applied after the constructor and before the component is added to the document.In the first scenario above, the author might want to adjust the class List Box extends HTMLElement let list Box = document.create Element('basic-list-box'); list Attribute('role', 'tabs'); // Set custom role append Child(list Box); // connected Callback will overwrite role! Another problem comes up in the second scenario above.At the moment, the v1 polyfills also feel like a beta, but they’re coming along quickly.As soon as the polyfills are stable enough, we’re looking forward to making a full release of Basic Web Components based on the v1 specs.