如何修改我的mongodb / mongoose查询，使其返回更详细的json？

Question

In my app I have a model for storing users. Each user can block other users, so I created an entry in this model that holds ids of blocked users:

...
blocked_user_ids: {type: [String]},
...

I also created an endpoint that allows me to get list of blocked users for a given user_id . Since I wanted to have each user's details on that list I had to do the following queries:

usersRoutes.get('/:id/blockedUsers/', functions.validateRequestsGET, function(req, res){
    var userId = req.params.id;

    async.auto({
        one: function(callback){
            findBlockedUsersIdsOfGivenUser(userId, callback);
        },
        two: ['one', function(callback, results){
            getBlockedUsersDetails(results.one, callback);
        }],
        final: ['one', 'two', function(callback, results) {
            res.status(200).send(results.two);
        }],
    }, function(err) {
        if (err) {
            sendError(res, err);
            return;
        }
    });
});

function findBlockedUsersIdsOfGivenUser(userId, callback) {
    var query = User.findOne({_id: userId}).select("blocked_user_ids");
    query.exec(function(err, blockedUsersIds){
        if(err) {
            return callback(err);
        }

        return callback(null, blockedUsersIds.blocked_user_ids);
    });
}

function getBlockedUsersDetails(blockedUsersIds, callback) {
    var query = User.find({_id: {$in: blockedUsersIds}});
    query.exec(function(err, blockedUsersDetails) {
        if(err) {
            return callback(err);
        }

        return callback(null, blockedUsersDetails);
    });
}

That worked well and returned me a json where each json node held information about specific user.

However, now my model changed, currently I had to change the string array into a structure:

...
blocked_user_ids: [{
    user_id: {type: String, required: true},
    is_anonymous: {type: Boolean, required: true}
}],
...

and now, besides getting user information in my json, I need to modify my queries so that the output json contains information about the flag is_anonymous - I want to add the value of that flag to each json node that represents each user. Can you help me with that?

Answer 1

So you can get the ids using Array.map and after you get the result add the is_anonymous property to each user.

function getBlockedUsersDetails(blockedUsersIds, callback) {
    // get all ids and also create users object for easier assigning of `is_anonymous` property
    var users = {};
    var ids = blockedUsersIds.map(function(a){
        users[a.user_id] = a.is_anonymous;
        return a.user_id;
    });
    // ids is same array you previously had as blockedUsersIds
    var query = User.find({_id: {$in: ids}});
    query.exec(function(err, blockedUsersDetails) {
        if(err) {
            return callback(err);
        }

        //blockedUsersDetails.forEach(function(user, index){            
            //user.is_anonymous = users[user.user_id];
        //});

        blockedUsersDetails.forEach(function(user, index){            
            blockedUsersDetails[index].is_anonymous = users[user.user_id];
        });

        return callback(null, blockedUsersDetails);
    });
}

I haven't tried this code so expect some bugs or typos :)