By convention, JavaScript objects that fire events have a corresponding "onevent" properties (named by prefixing "on" to the name of the event). The c-todo-app parent component passes a property or invokes a method in the child component. I remember the days when I used to go through a lot of expressions in Visualforce Pages, and it is REALLY hard to read/debug such inline expressions. We need to add prefix as on before the custom event name and in parent component we need to invoke the event listener as handleCustomEvent using onmycustomevent attribute. All browser compatibility updates at a glance, Frequently asked questions about MDN Plus. The c-todo-item child component dispatches an event to the parent c-todo-app component. detail.html has a conditional directive (remember those from Unit 2?) In particular, while the native DOM events all are lowercase strings with no hyphens, a reasonable developer might decide they want to include hyphens in event names for legibility. This is done by passing the same AbortSignal to the addEventListener() call for all the event handlers that you want to be able to remove together. In a pub-sub pattern, one component publishes an event and other components subscribe to receive and handle the event. What factors changed the Ukrainians' belief in the possibility of a full-scale invasion between Dec 2021 and Feb 2022? ', 'srcdoc attribute is disallowed on