javascript在猫鼬查询和保存期间推送到数组内部循环

Question

I don't know to structure the Javascript to return a list of updated json objects after performing a mongoose query and save.

Currently I'm trying something similar to the code below but with no luck. The resBankMembers array is always empty.

Json from request body:

[
 {
   _id : (some id), 
   name = (some name)
 },  
 { _id : (some id), 
   name = (some name) 
 }
} 

Code example (non working):

var jsonText = JSON.stringify(req.body);
var jsonObject = JSON.parse(jsonText);
var resBankmembers = [];    

jsonObject.forEach(function(updatebankmember) {
    var bid = ObjectID(updatebankmember._id);
    BankMember.findOne({ "_id" : bid }, function(error,bankmember) {
        if (error) {
            console.log(error);
        }
        else {  
            bankmember.name = updatebankmember.name;
            bankmember.save(function (error) {
                if(error) {
                    console.log(error);
                }
                else {
                    resBankmembers.push(bankmember);
                }
            });
        }               
    });
});
res.send(200, resBankmembers);

Please help!

Answer 1

Try this:

var jsonText = JSON.stringify(req.body);
var jsonObject = JSON.parse(jsonText);

jsonObject.forEach(function(updatebankmember, i) {
    var bid = ObjectID(updatebankmember._id);
    BankMember.findOne({ "_id" : bid }, function(error,bankmember) {
        if (error) {
            console.log(error);
        }
        else {  
            bankmember.name = updatebankmember.name;
            bankmember.save(function (error) {
                if(error) {
                    console.log(error);
                }
                else {
                    jsonObject[i].id   = bankmember.id;
                    jsonObject[i].name = bankmember.name;
                }
            });
        }               
    });
});
res.send(200, jsonObject);

Instead of trying to push objects into an array, just update the already parsed JSON .

I also recommend using this for the else in the save function:

else {
     for (var key in bankmember) {
         jsonObject[i][key] = bankmember[key];
     }
}

In case you expand the bankmember object later on.

The forEach function isn't supported in IE 8 and Below so I recommend:

if (Array.prototype.forEach) {
    Array.prototype.forEach = function (fun) {
        for (var i = 0; i < this.length; i++) {
            fun.call(this, this[i], i)
        }
    };
}

Unless you don't want to support IE. I hope this helped.