Question

Im having some issues with deleting an entry from mongo DB. Im using node-mongodb-native

The code with a issue is

ArticleProvider.prototype.delete = function(id, callback) {
    this.getCollection(function(error, article_collection) {
      if( error ) callback(error)
      else {
        article_collection.findAndRemove({_id: article_collection.db.bson_serializer.ObjectID.createFromHexString(id)}, function(error, result) {
          if( error ) callback(error)
          else callback(null, result)
        });
      }
    });
};

its a strange issue because i have a function to return a single article that is

ArticleProvider.prototype.findById = function(id, callback) {
    this.getCollection(function(error, article_collection) {
      if( error ) callback(error)
      else {
        article_collection.findOne({_id: article_collection.db.bson_serializer.ObjectID.createFromHexString(id)}, function(error, result) {
          if( error ) callback(error)
          else callback(null, result)
        });
      }
    });
};

and that works like a charm

this is my error

500 TypeError: Cannot read property 'length' of undefined
at Function.createFromHexString (/Users/username/express_blog/node_modules/mongodb/lib/mongodb/bson/objectid.js:226:22)

it seems to be an issue with the type of id (or it seems).

Answer 1

The id argument you are passing must be undefined.

Here is the source to the current version of that function , or the newest one I could find on github.

Note that the framework code here does not handle (typeof hexString === 'undefined')

ObjectID.createFromHexString = function createFromHexString (hexString) {
  // Throw an error if it's not a valid setup
  if(hexString != null && hexString.length != 24) throw new Error("Argument passed in must be a single String of 12 bytes or a string of 24 hex characters in hex format");

  var len = hexString.length;

  if(len > 12*2) {
    throw new Error('Id cannot be longer than 12 bytes');
  }

  var result = ''
    , string
    , number;

  for (var index = 0; index < len; index += 2) {
    string = hexString.substr(index, 2);
    number = parseInt(string, 16);
    result += BinaryParser.fromByte(number);
  }

  return new ObjectID(result);
};