eslint-plugin-delegated-events
v1.0.0
Published
Disallow delegating high-frequency events.
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eslint-plugin-delegated-events
Disallow delegating high-frequency events.
The delegated-events library registers all event listeners on
document
, using selectors to determine an observer's interest in each
event.
on('click', '.js-button', function(event) {
console.log('clicked', this)
})
This is appropriate for most events, like click
and change
, but
events fired at a high rate need to be directly bound with
element.addEventListener
to avoid performance problems.
This lint rule disallows delegated event listeners on the following events:
- input
- keydown
- keypress
- keyup
- mouseout
- mouseover
- mousemove
- scroll
Top level listener registration
Registering a delegated event listener by calling on
in a conditional branch,
loop, or function can result in duplicate registrations and invoking the
listener multiple times. The global-on
lint rule requires on
to be called
only in the top level module scope.
Installation
You'll first need to install ESLint:
$ npm install eslint --save-dev
Next, install eslint-plugin-delegated-events
:
$ npm install eslint-plugin-delegated-events --save-dev
Note: If you installed ESLint globally (using the -g
flag) then you must also install eslint-plugin-delegated-events
globally.
Usage
Add delegated-events
to the plugins section of your .eslintrc
configuration file. You can omit the eslint-plugin-
prefix:
{
"plugins": [
"delegated-events"
],
"rules": {
"delegated-events/global-on": 2,
"delegated-events/no-high-freq": 2
}
}
Development
npm install
npm test
License
Distributed under the MIT license. See LICENSE for details.