party_bid_core三种数据结构分析

１．第一种数据结构：

activities = [
    {
        name: "first activity",
        sign_ups: [],
        bids: []
    },
    {
        name: "first activity",
        sign_ups: [
            {
                name: "仝键",
                phone: "13600000000"
            },
            {
                name: "于硕",
                phone: "15600000000"
            }
        ],
        bids: [
            {
                name: "竞价1",
                biddings: [
                    {
                        name: "仝键",
                        phone: "13600000000",
                        price: "12"

                    },
                    {
                        name: "于硕",
                        phone: "15600000000",
                        price: "10"
                    }
                ]
            }
        ]
    }
];

　　这种数据结构所有的信息都存储在一个数组里，而每个活动又存储了name,sign_ups,bids，sign_ups和bids又分别存储活动报名和竞价信息．结构非常清晰，要取某一数据也很好取．但要存储或修改数据时由于嵌套比较多，所以步骤比较麻烦．以存储竞价信息为例：

Bidding.prototype.save_bidding = function () {
    var bidding = this;
    var activities = Activity.get_activities();
    _.map(activities, function (activity) {
        if (activity.name == Activity.get_active_activity_name()) {
            _.map(activity.bids, function (bid) {
                if (bid.name == Bid.get_current_bid()) {
                    bid.biddings.push(bidding)
                }
            })
        }
    })
    localStorage.setItem("activities", JSON.stringify(activities));
}

　
２．第二种数据结构：

activities = {
    "0": {
        name: "first activity",
        sign_ups: [],
        bids: [],
        biddings: {}
    },
    "1": {
        name: "second activity",
        sign_ups: [
            {
                name: "仝键",
                phone: "13600000000"
            },
            {
                name: "于硕",
                phone: "15600000000"
            }
        ],
        bids: ["竞价1", "竞价2"],
        biddings: {
            "竞价1": [
                {
                    phone: "13600000000",
                    price: "12"
                },
                {
                    phone: "15600000000",
                    price: "10"
                }
            ],
            "竞价2": [
                {
                    phone: "13600000000",
                    price: "10"

                },
                {
                    phone: "15600000000",
                    price: "12"
                },
            ]
        }
    ]
};

　　这种数据结构所有的信息都存储在一个hash表里，每个活动都对应一个key,其value又包括name,sign_ups,bids，biddings，结构也比较清楚．相对于第一种结构，他把竞价名称抽成一个数组存储起来，用起来更加方便.修改数据时，找到相对应的key，修改它的key就行．以存储竞价信息为例：

Bidding.prototype.save_bidding = function () {
    var bidding = this;
    var bid = Activity.get_current_bid();
    var activities = Activity.get_activities();
    _.map(activities, function (value, key) {
        if (key == Activity.get_current_activity()) {
            value.biddings[bid].push(bidding);
        }
    })
    localStorage.setItem("activities", JSON.stringify(activities));
}

３．第三种数据结构：

activities = [
    {
        id: "0",
        name: "first activity"
    },
    {
        id: "1",
        name: "second activity"
    }
];
sign_ups = [
    {
        name: "仝键",
        phone: "13600000000",
        activity_id: "0"
    },
    {
        name: "于硕",
        phone: "15600000000",
        activity_id: "0"
    }
]
bids = [
    {
        name: "竞价1",
        activity_name: "0",
        biddings: [
            {
                phone: "13600000000",
                price: "9"
            },
            {
                phone: "15600000000",
                price: "10"
            }
        ]
    }
];

　　这种数据结构把活动名称（activities），报名信息（sign_ups），竞价信息（bids）分开存储，结构不太清晰．取数据时不太方便，但是嵌套较少，修改或存储数据时特别方便，以保存竞价信息为例：

Bid.create_new_bid = function (activity_id) {
    var bids = Bid.get_bids();
    var bid = new Bid(activity_id);
    bids.push(bid);
    localStorage.setItem("bids", JSON.stringify(bids));
}

　　　总之，三种数据结构各有优劣，从第一种到第三种数据结构扩展性越来越好，存储数据比较方便；结构变的不太清晰，取数据不太方便．第一种是要一层一层的取，第三种是要筛选出满足特定条件的值（此处必须小心找出所有要满足的条件）．