问题
I am working on my first bigger Polymer application and currently have around 30 components. Most of the components need to be able to display (modal) message boxes. For this I implemented a message box component wrapping paper-dialog (similar to other message box components available).
What I don't like is that in every component which wants to display message boxes I need to define an element
<my-message-box id="message-box"></my-message-box>
and then call it like this
this.$["message-box"].information("Something happened...");
This works but my gut feeling is that a message box should be more like a global service, a singleton maybe. In C# f.e. there exists a static method on the MessageBox class.
Is the above mechanism really the recommended way to do it or are there better solutions to it?
回答1:
My current approach is to create error-dialog
and add it as a sibling to my main-app
in index.html
:
<body>
<main-app></main-app>
<error-dialog></error-dialog>
<noscript>
Please enable JavaScript to view this website.
</noscript>
</body>
error-dialog
's ready()
method adds a custom event:
ready() {
super.ready();
this.addEventListener('o_error', e => this._errorListener(e));
}
_errorListener(e) {
this.o_error = e.detail;
this.$.errorDlog.open();
}
Now I can open error-dialog
from anywhere with
let msg = ...
const dlog = document.querySelector('error-dialog');
dlog.dispatchEvent(new CustomEvent('o_error', {detail: msg, bubbles: true, composed: true}));
来源:https://stackoverflow.com/questions/47213166/message-boxes-in-polymer-applications