如果对象不存在或为空，如何基于预定义的结构动态添加对象？

Question

让我们说这是我的api响应

user = {
    profile: {
        name: "John",
        age: 32,
        links: [
            {
                github: {
                    name: "John",
                    url: "https://github.com/john"
                },
                facebook: {
                    name: "John",
                    url: "https://facebook.com/john"
                }
            }
        ]
    },
    posts: [
        {
            id: 1,
            title: "First post"
        },
        {
            id: 2,
            title: "Second post"
        }
    ]
}

我的预定义对象结构是

predefinedUserObj = {
    profile: {
        name: "",
        age: "",
        links: [
            {
                github: {
                    name: "",
                    url: "",
                },
                facebook: {
                    name: "",
                    url: "",
                }
            }
        ]
    },
    posts: []
}

我从user object获得了Api，并且想将api响应与预定义的结构进行比较。

示例1：

如果api响应中user.profile.links[0].github的值为null，那么我想将预定义结构中的任何值分配给该属性。 （在这种情况下为{ name: "", url:" }）

示例2：

如果user.profile.links的值为null，那么我想从预定义的结构中分配预定义的值/对象（在本例中为`

[
    {
        github: {
            name: "",
            url: "",
        },
        facebook: {
            name: "",
            url: "",
        }
    }
]

因此，只要结构不匹配，我都想用预定义结构中的预填充值替换它。我怎样才能做到这一点？预先感谢。

Answer 1

您可以使用递归函数检查对象中是否存在预定义键。如果对象键未定义，为空或为null，则将预定义键值分配给对象：

function object_filter_recursive(obj, predefined) {

    if ( typeof(predefined) == "object") {
	Object.keys(predefined).forEach(function (k){
            if (typeof obj[k] !== 'undefined' && obj[k] != '') {
                if ( typeof(predefined[k]) == "object") {
                    return object_filter_recursive(obj[k], predefined[k]);
                } else {
                    predefined[k] = obj[k];
                }
             }
        })
    }

    return predefined;
}

var predefined = {
    profile: {
        name: "default name",
        age: "", // if no default value, just leave it empty //
        links: [
            {
                github: {
                    name: "default github",
                    url: "default github link",
                },
                facebook: {
                    name: "default facebook name",
                    url: "default facebook link",
                }
            }
        ]
    },
    posts: ""
}

var obj = {
    profile: {
        name: "john",
        age: "40",
        links: [
            {
                github: {
                    name: "",
                    url: "",
                },
                facebook: {
                    name: "",
                    url: "",
                }
            }
        ]
    },
    posts: [
    	{something1: "value1"},
        {something2: "value2"}
    ]
}


obj = object_filter_recursive(obj, predefined);
console.log(obj);