Question

我是Parse的新手，我只是创建了我的第一个Cloud Code，我遇到了Parse.Query没有完成的问题，因为显然response.success()显然会被过早调用。< / p>

Parse.Cloud.beforeSave("items",function(request,response){
    hasPictures = calc(request);
    request.object.set("hasPictures",hasPictures);

    response.success();
});

function calc(request){
    var hasPictures = false;
    var userPictureCount = getPictureCountForUser(request.object.get("uniqueIdentifier"));

    // something else is being calculated here. removed it so simplify

    if(userPictureCount > 0)
    hasPictures = true;

    return hasPictures;
}

var getPictureCountForUser = function(uniqueIdentifier){

    var query = new Parse.Query("items");
    if(Parse.User.current()){   
        a.equalTo("userId", Parse.User.current().id);
    }else{
        query.equalTo("uniqueIdentifier", uniqueIdentifier);
    }

    query.find({
        success: function(results){
            //console.log(results.length + ' pictures found!');
            console.log(results);
            // return results.length; 
            response.success(results);        
        },
        error: function(error) {
            response.error("Query failed. Error = " + error.message);
        }
    });
};

我知道我不得不处理Promises。但我不知道如何实现它。

Parse.Query getPictureCountForUser()中的response.success()从未发现过某些内容，因为calc()位于错误的位置。我必须在哪里放置它，特别是在response.success()之间？

这样每个函数都会等到另一个函数完成，然后再过早发送=and(not(len(A1)=17),not(isblank(a1)))。

谢谢！

Answer 1

你可以使用promises但是对于你的特定情况，如果你不想使用promises，你只能使用回调，不再是这样的：

Parse.Cloud.beforeSave("items",function(request,response){
    hasPictures = calc(request, function(hasPictures) {
        // i don't know your logic, you could do a response.success of failure, what do you need
        request.object.set("hasPictures",hasPictures);

        response.success();
    });
});

function calc(request, callback){
    var hasPictures = false;
    getPictureCountForUser(request.object.get("uniqueIdentifier"), function(userPictureCount) {
    if(userPictureCount > 0)
        hasPictures = true;

    callback(hasPictures);
    });
};

var getPictureCountForUser = function(uniqueIdentifier, callback){
    var query = new Parse.Query("items");
    if(Parse.User.current()){   
        a.equalTo("userId", Parse.User.current().id);
    }else{
        query.equalTo("uniqueIdentifier", uniqueIdentifier);
    }

    query.find({
        success: function(results){
            callback(results.length);
        },
        error: function(error) {
            callback(-1);
            //response.error("Query failed. Error = " + error.message);
        }
    });
};

我在哪里放response.success（）？

1 个答案: