Parse.com beforeSave获取脏值

Question

On the parse.com info log are the keys and values of the update visible: This is valid JSON, see

{
    "original": {
        "countReplies": 0,
        "owner": {
            "__type": "Pointer",
            "className": "_User",
            "objectId": "OKjocXCfUR"
        },
        "rating": 0,
        "message": "affdgf",
        "objectId": "7Rdu6ZWugr",
        "createdAt": "2015-02-03T11:57:06.523Z",
        "updatedAt": "2015-02-03T11:57:06.523Z"
    },
    "update": {
        "rating": -1
    }
}

How can I access the "update" object from the request in beforeSave? Here are some attempts without success:

console.log("1. update: " + request.object.dirtyKeys());
console.log("2. original: " + JSON.stringify(request.object));
console.log("3. rating original: " + request.object.get("rating"));
console.log("4. isDirty: " + request.get("update"));
console.log("5. " + request.object.get("update"));
console.log("6. " + update.get("rating"));
console.log("7. " + request.get("Input"));

Answer 1

Update is neither a property of request.object or dirtyKeys() , it is simply the JSON being passed to the server. By the time you have reached function level it has already been interpreted by the SDK .

Array of string dirtyKeys( ) Returns an array of keys that have been modified since last save/refresh

Returns: Array of string

Your request object IS the updated version of the object. This is what the SDK is comparing to the database to determine which keys are dirty.

So, your updates are simply in the request.object

request.object.get("rating");