react mixins编写

var LogMixin = {
    componentWillMount: function () {
        console.log('Component will mount');
    },
    componentDidMount: function () {
        console.log('Component did mount');
    }
};

var AComponent = React.createClass({
    mixins: [LogMixin],
    render: function () {
        return (
            <div>AComponent</div>
        )
    }
});

var BComponent = React.createClass({
    mixins: [LogMixin],
    render: function () {
        return (
            <div>BComponent</div>
        )
    }
});

mixins的详细学习：https://segmentfault.com/a/1190000002704788

Mixins

利用React的Mixins，编写的代码就像这样的：

var LogMixin = {
    componentWillMount: function () {
        console.log('Component will mount');
    },
    componentDidMount: function () {
        console.log('Component did mount');
    }
};

var AComponent = React.createClass({
    mixins: [LogMixin],
    render: function () {
        return (
            <div>AComponent</div>
        )
    }
});

var BComponent = React.createClass({
    mixins: [LogMixin],
    render: function () {
        return (
            <div>BComponent</div>
        )
    }
});

Mixins有点类似AOP。所谓的mixins就是将组件里的方法抽出来。实际上Mixins里的this是指向组件的，使用了Mixins以后，组件也可以调用Mixins里的方法。

组件调用Mixins方法

var Mixin = {
    log:function(){
       console.log('Mixin log');
    }
};

var Component = React.createClass({
    mixins: [Mixin],
    componentWillMount: function () {
        this.log();
    },
    render: function () {            
        return (
            <div>Component</div>
        )
    }
});

控制台打印：

$ Mixin log

生命周期方法

Mixins里也可以编写组件生命周期的方法，需要注意的是：Mixins里的方法并不会覆盖组件的生命周期方法，会在先于组件生命周期方法执行。

var Mixin = {
    componentWillMount: function () {
        console.log('Mixin Will Mount');
    }
};

var Component = React.createClass({
    mixins: [Mixin],
    componentWillMount: function () {
        console.log('Component Will Mount');
    },
    render: function () {
        return (
            <div>Component</div>
        )
    }
});

控制台打印：

$ Mixin Will Mount
$ Component Will Mount

使用多个Mixin

组件也可以使用多个Mixin

var AMixin = {
    componentWillMount: function () {
        console.log('AMixin Will Mount');
    }
};

var BMixin = {
    componentWillMount: function () {
        console.log('BMixin Will Mount');
    }
};

var Component = React.createClass({
    mixins: [AMixin,BMixin],
    componentWillMount: function () {
        console.log('Component Will Mount');
    },
    render: function () {
        return (
            <div>Component</div>
        )
    }
});

控制台打印：

$ AMixin Will Mount
$ BMixin Will Mount
$ Component Will Mount

数组引入的顺序，决定了Mxins里生命周期方法的执行顺序。

不允许重复

除了生命周期方法可以重复以外，其他的方法都不可以重复，否则会报错

情景1

var AMixin = {
    log: function () {
        console.log('AMixin Log');
    }
};

var BMixin = {
    log: function () {
        console.log('BMixin Log');
    }
};

var Component = React.createClass({
    mixins: [AMixin,BMixin],
    render: function () {
        return (
            <div>Component</div>
        )
    }
});

情景2

var Mixin = {
    log: function () {
        console.log('Mixin Log');
    }
};

var Component = React.createClass({
    mixins: [Mixin],
    log:function(){
        console.log('Component Log');
    },
    render: function () {
        return (
            <div>Component</div>
        )
    }
});

以上两种情景，都会报错，控制信息如下，所以使用的时候要小心了