JavaScript cheat sheet: Difference between revisions
David Mudrak (talk | contribs) mNo edit summary |
David Mudrak (talk | contribs) mNo edit summary |
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Line 47: | Line 47: | ||
let data = {}; | let data = {}; | ||
PubSub.publish(eventName, data); | PubSub.publish(eventName, data); | ||
</code> | |||
=== Strings (core/str) === | |||
<code js> | |||
import {get_string as getString} from 'core/str'; | |||
const sayHello = async () => { | |||
window.console.log(await getString('identifier', 'tool_jsdemo'); | |||
} | |||
</code> | </code> |
Revision as of 21:23, 29 October 2020
Locating DOM elements
// Get element by identifier.
let root = document.getElementById('uniqueidentifier');
// Get element within another element by attribute.
let widget = querySelector('[data-widget="widgetname"]');
// Find all elements within another element and do something with them.
let missingItems = root.querySelectorAll(':scope [data-region="itemname"].missing');
missingItems.forEach(item => {
window.console.log(item);
});
// Find the closest parent element matching the selector.
let region = widget.closest('[data-region]');
CSS classes
// Check if the element has a certain class.
if (e.target.classList.contains('classname')) {
// Add a new CSS class to the element.
e.target.classList.add('someclassname');
// Remove a CSS class from the element.
e.target.classList.remove('anotherclassname');
}
Custom events (core/pubsub)
import * as PubSub from 'core/pubsub';
let eventName = 'tool_jsdemo/modulename:eventname';
// Subscribe as the event handler.
PubSub.subscribe(eventName, data => {
window.console.log(data);
});
// Trigger the event with custom data passed to the subscribers.
let data = {};
PubSub.publish(eventName, data);
Strings (core/str)
import {get_string as getString} from 'core/str';
const sayHello = async () => {
window.console.log(await getString('identifier', 'tool_jsdemo');
}