Mixins allow code to be shared between multiple React components. They're pretty similar to mixins in Python or traits in PHP. Let's look at a simple example:
Mixins allow code to be shared between multiple React components. They are pretty similar to mixins
in Python or traits in PHP. Let's look at a simple example:
```javascript
```javascript
// mixins-simple.js
var MyMixin = {
var MyMixin = {
getMessage: function() {
getMessage: function() {
return 'hello world';
return 'hello world';
@ -24,10 +24,13 @@ var MyComponent = React.createClass({
});
});
```
```
A class can use multiple mixins. Multiple mixins can also override any of the lifecycle methods and they'll be called for each mixin. Here's an example:
A class can use multiple mixins, but no two mixins can define the same method. Two mixins can, however,
implement the same [lifecycle method](component-lifecycle.html). In this case, each implementation will be invoked one after another.
The only exception is the `shouldComponentUpdate` lifecycle method. This method may only be implemented once
(either by a mixin or by the component).
```javascript
```javascript
// mixins-advanced.js
var Mixin1 = {
var Mixin1 = {
componentDidMount: function() {
componentDidMount: function() {
console.log('Mixin1.componentDidMount()');
console.log('Mixin1.componentDidMount()');
@ -49,7 +52,7 @@ var MyComponent = React.createClass({
});
});
```
```
When MyComponent is mounted in the page the following text will print to the console:
When `MyComponent` is mounted into the page, the following text will print to the console:
```
```
Mixin1.componentDidMount()
Mixin1.componentDidMount()
@ -58,4 +61,5 @@ Mixin2.componentDidMount()
## When should you use mixins?
## When should you use mixins?
In general, add a mixin whenever you want a component to share some utility methods, public interface, or lifecycle behavior. Often it's appropriate to use them as you would use a superclass in another OOP language.
In general, add a mixin whenever you want a component to share some utility methods, public interface,
or lifecycle behavior. Often it's appropriate to use them as you would use a superclass in another OOP language.