JS 变量绑定

JS 变量绑定.js

    var testData = {
    "a.b.c": 9,
    gs: [3,1,23],
    nest: {
        a:233,
        "b.c": 911,
        b:{
            g: 254,
            c: 623
        }
    }
}


function bindObjeChangeEvent(obj, propertyName, getter = null, setter = null){
    if(!getter && !setter){
        return;
    }

    if(obj.hasOwnProperty(propertyName)){
        var val = obj[propertyName];
        if(typeof val == "object" && !Array.isArray(val)){
            return;
        }
        if(!obj.hasOwnProperty("_store")){
            var store = {};
            Object.defineProperty(obj, "_store", {
                "enumerable": false,
                "configurable": false,
                get: function(){ return store; },
            });
        }
        obj._store[propertyName] = obj[propertyName];
        Object.defineProperty(obj, propertyName, {
            enumerable: true, 
            configurable: true,
            get: function(){
                if(typeof getter == "function"){
                    return getter(obj, obj._store[propertyName]);
                }
                return val;
            },
            set: function(newVal){
                if(typeof setter == "function" && val != newVal){
                    setter(obj, propertyName, newVal)
                }
            }
        });
        return;
    }
    let pathList= propertyName.split(".");
    let currObj = obj[pathList.shift()];
    if(pathList.length == 0){
        return;
    }

    return bindObjeChangeEvent(currObj, pathList.join("."), getter, setter);
}


bindObjeChangeEvent(testData, "nest.b.c", function(obj, val){ 
    console.log("你读取我干啥呢");
    return val;
}, function(obj, propertyName, newVal){
    var oldVal = obj._store[propertyName];
    console.log("你改我干什么呢 " + oldVal + " -> " + newVal);
    obj._store[propertyName] = newVal;
});


bindObjeChangeEvent(testData, "nest", function(obj, val){ 
    console.log("nest 你读取我干啥呢");
    return val;
}, function(obj, propertyName, newVal){
    var oldVal = obj._store[propertyName];
    console.log("nest 你改我干什么呢 " + oldVal + " -> " + newVal);
    obj._store[propertyName] = newVal;
});

console.log(testData.nest["b.c"]);
testData.nest["b.c"] = 233;
console.log(testData.nest["b.c"]);


function getSetPath(obj, propertyName, value = undefined){
    if(obj.hasOwnProperty(propertyName)){
        if(value !== undefined){
            obj[propertyName] = value;
        }
        return obj[propertyName];
    }
    let pathList= propertyName.split(".");
    let currObj = obj[pathList.shift()];
    if(pathList.length == 0){
        return null;
    }
    return getSetPath(currObj, pathList.join("."), value);
}