Question

现在我在减速机中执行以下操作：

export default function (state = null, action) {

    if(state==null)
    {
        state = [
            {
                id: 1,
                first: "Bucky",
                last: "Roberts",
                age: 71,
                description: "Bucky is a React developer and YouTuber",
                thumbnail: "http://i.imgur.com/7yUvePI.jpg"
            },
            {
                id: 2,
                first: "Joby",
                last: "Wasilenko",
                age: 27,
                description: "Joby loves the Packers, cheese, and turtles.",
                thumbnail: "http://i.imgur.com/52xRlm8.png"
            },
            {
                id: 3,
                first: "Madison",
                last: "Williams",
                age: 24,
                description: "Madi likes her dog but it is really annoying.",
                thumbnail: "http://i.imgur.com/4EMtxHB.png"
            }
        ]
    }

    switch (action.type) {
        case 'USER_DELETED':
            return state.filter(user => user.id !== action.userIdToDelete);
    }

    return state;
}

所以我检查状态是否为null，如果是，则填充它。有没有更好的方法来做到这一点，即不从内部填充我的减速机？对我来说看起来很糟糕......

Answer 1

不要将默认值设为null - 请执行以下操作

        initialState = [
        {
            id: 1,
            first: "Bucky",
            last: "Roberts",
            age: 71,
            description: "Bucky is a React developer and YouTuber",
            thumbnail: "http://i.imgur.com/7yUvePI.jpg"
        },
        {
            id: 2,
            first: "Joby",
            last: "Wasilenko",
            age: 27,
            description: "Joby loves the Packers, cheese, and turtles.",
            thumbnail: "http://i.imgur.com/52xRlm8.png"
        },
        {
            id: 3,
            first: "Madison",
            last: "Williams",
            age: 24,
            description: "Madi likes her dog but it is really annoying.",
            thumbnail: "http://i.imgur.com/4EMtxHB.png"
        }
    ];

    export default function (state = initalState, action) {
     ...
    }

Answer 2

您应该始终将默认状态值设置为您期望的类型，因此function (state=[])更好。将其设置为null是一种反模式。

然后，对于数据作为默认初始状态，您应该使用createStore中的第二个参数来设置初始状态：http://redux.js.org/docs/api/createStore.html

如何在React / Redux中最好地初始化状态/设置第一个状态

2 个答案: