javascript - Backbone 实体

Question

我是 backbone 的新手。但是当我研究模型实体时，我不明白一些事情。如果我们可以像 java 或 C# 这样的标准语言一样定义模型属性，那就太好了。有没有可能是这样的。所以我的想法是这样的:

MyEntity = Backbone.Model.extend({
    // define class property here
    defaults: {
        name: null,
        surname: null
    }
});

var entity = new MyEntity();

//My Idea:
name = entity.get('name'); // return null
test = entity.get('test'); // this should throw exception, because test property does not exist
exist = entity.has('name'); // should return true. Property exist, but is empty
entity.set('test2', 'hello'); // this should threw exception, property test2 does not exist

// Reality:
name = entity.get('name'); // return null
test = entity.get('test'); // return undefined
exist = entity.has('name'); // return false
entity.set('test2', 'hello'); // ok, valid

那么是否可以修改 Backbone 模型使其像这样工作？非常感谢

Answer 1

您可以设置自己的自定义 getter 和 setter。

var MyEntity = Backbone.Model.extend({
    defaults: {
        name: null,
        surname: null
    },

    customHas: function (key) {
        return this.attributes.hasOwnProperty(key);
    },

    customGet: function (key) {
        if (this.customHas(key)) {
            return this.get(key);

        } else {
            throw('property does not exist');
        }
    },

    customSet: function (key, val) {
        if (this.customHas(key)) {
            this.set(key, val);

        } else {
            throw('property does not exist');
        }
    }
});

See this example fiddle .