nodejs + mongodb 中的订单发布

Question

I am ordering the posts by age of the user and not by date of the post, I am using nodejs and mongodb:

 router.get("/", function(req, res, next) {
  if (req.session._id && req.session.user) {
    user.getAll((err, users) => {
      var posts = [];
      for (var i = 0; i < users.length; i++) {
        for (var j = 0; j < users[i].posts.length; j++) {
          users[i].posts[j].timeago = ta.ago(users[i].posts[j].createdAt);
          posts.push({ user: users[i], post: users[i].posts[j] });
        }
      }

      user.findOne({ username: req.session.user }, (error, req_user) => {
        /*   for(var z=0;z<req_user.followers.length;z++) {
            user.findOne({_id:req_user.followers[z]}, (e,followedUser) => {
              posts.push(followedUser.posts)
            })
          }
          */
        var lastSeen = ta.ago(req_user.lastLogin);
        //console.log(posts)
        res.render("home", {
          user: req_user,
          title: req.app.conf.name,
          lastSeen: lastSeen,
          people: users,
          posts: posts.reverse()
        });
      });
    });
  } else {
    res.render("auth/login", {
      title: req.app.conf.name,
      error: false
    });
  }
});

I would like to order it by the most recent post, any solution?

I think the main part of the problem is:

posts.push({ user: users[i], post: users[i].posts[j] });

and that you should use.sort (createdAt), but I don't know exactly how.

Answer 1

You should sort the posts before adding them to the array, something like the following:

function sort_array_of_obj(a, b) {
  if (a.createdAt < b.createdAt){
    return -1;
  }
  if (a.createdAt > b.createdAt){
    return 1;
  }
  return 0;
}

for (var i = 0; i < users.length; i++) {        
    users[i].posts.sort(sort_array_of_obj)

    for (var j = 0; j < users[i].posts.length; j++) {
      users[i].posts[j].timeago = ta.ago(users[i].posts[j].createdAt);      
    }
    posts.push({ user: users[i], post: users[i].posts[j] });
}