### How do I pass an event handler (like onClick) to a component?
Pass event handlers and other functions as props to child components:
```jsx
<buttononClick={this.handleClick}>
```
If you need to have access to the parent component in the handler, you also need to bind the function to the component instance (see below).
### How do I bind a function to a component instance?
There are several ways to make sure functions have access to component attributes like `this.props` and `this.state`, depending on which syntax and build steps you are using.
>Using `Function.prototype.bind` in render creates a new function each time the component renders, which may have performance implications; (see below).
#### Example: Passing params using data-attributes
Alternately, you can use DOM APIs to store data needed for event handlers. Consider this approach if you need to optimize a large number of elements or have a render tree that relies on React.PureComponent equality checks.
### How can I prevent a function from being called too quickly or too many times in a row?
If you have an event handler such as `onClick` or `onScroll` and want to prevent the callback from being fired too quickly, you can wrap the handler with a utility such as [`_.debounce`](https://lodash.com/docs#debounce) or [`_.throttle`](https://lodash.com/docs#throttle). For a given `delay`, say `100ms`, debouncing calls the handler after activity stops for that amount of time; throttling prevents the handler from being called more than once per `delay`. See a visualization [here](http://demo.nimius.net/debounce_throttle/).
Note: Call `event.persist()` when accessing events asynchronously to prevent the synthetic event from being recycled by [event pooling](/docs/events.html#event-pooling). See the debounce [example](#debounce) below.