Develop Reference

How to access array elements that are defined in another array of Mongoose scheme object Array?

This is the User schema in mongoose:
var userSchema = new mongoose.Schema({
email: {
type: String,
unique: true,
required: true,
},
name: {
type: String,
required: true,
},
Addtasks: [
{
topic: String,
words: Number,
keywords: String,
website: String,
otherdetails: String,
exampleRadios: String,
deadline: Date,
Date: String,
fileName: String,
Bigpaths: [],
},
],
});
module.exports = mongoose.model('User', userSchema);
I want to use/access the Bigpaths array, which is defined inside the Addtasks array, which is defined in User. Data is already are there in mongoDB, which I have inserted via UI page. I am trying the following code but I am getting this error in console:
data.Addtasks[Object.keys(data.Addtasks).length - 2].Bigpaths.forEach(
(element) => {
// ...
}
)
as
TypeError: Cannot read property 'Bigpaths' of undefined
at \Desktop\grumpytext\routes\index.js:99:71
Code:
const { files } = req;
User.findOne({ email: req.user.email }, function (error, data) {
if (error) {
console.log('Three');
} else if (data) {
if (Object.keys(data.Addtasks).length > 1) {
data.Addtasks[Object.keys(data.Addtasks).length - 2].Bigpaths.forEach(
(element) => {
files.forEach((currentElement) => {
if (element.name == currentElement.filename) {
files.pull(currentElement.filename);
}
});
}
);
}
}
});
How to resolve this error or how to access all the elements of Bigpaths array so that I can iterate it with forEach loop?

I'm not sure here, but I think you need to populate Addtasks prior to manipulating it:
const files = req.files;
User.findOne({email:req.user.email}).populate('Addtasks').exec((error, data) => {
if (error) {
console.log("Three");
}
else
{
if(data)
{
if(Object.keys(data.Addtasks).length > 1)
{
console.log("Addtasks count: " + Object.keys(data.Addtasks).length);
data.Addtasks[Object.keys(data.Addtasks).length - 2].Bigpaths.forEach(element => {
files.forEach(currentElement => {
if(element.name == currentElement.filename)
{
files.pull(currentElement.filename);
}
})
});
}
}
}
});
Please notice the log console.log("Addtasks count: " + Object.keys(data.Addtasks).length); - in case the solution does not work, I advise to add some prints, especially to check if the count of elements is as expected or properties within an object are fine.

Mongoose Schema method: Error - model method is not a function

I have two Mongoose model schemas as follows. The LabReport model contains an array of the referenced SoilLab model. There is a static method in the SoilLab model that I was using to select which fields to display when LabReport is retrieved.
//LabReport.js
var mongoose = require("mongoose");
var SoilLab = mongoose.model("SoilLab");
var LabReportSchema = new mongoose.Schema(
{
labFarm: { type: mongoose.Schema.Types.ObjectId, ref: "Farm" },
testName: { type: String },
soilLabs: [{ type: mongoose.Schema.Types.ObjectId, ref: "SoilLab" }],
},
{ timestamps: true, usePushEach: true }
);
LabReportSchema.methods.toLabToJSON = function () {
return {
labReport_id: this._id,
testName: this.testName,
soilLabs: this.soilLabs.SoilToLabJSON(),
};
};
mongoose.model("LabReport", LabReportSchema);
//SoilLab.js
var mongoose = require("mongoose");
var SoilLabSchema = new mongoose.Schema(
{
description: { type: String },
sampleDate: { type: Date },
source: { type: String },
},
{ timestamps: true, usePushEach: true }
);
SoilLabSchema.methods.SoilToLabJSON = function () {
return {
description: this.description,
sampleDate: this.sampleDate,
source: this.source,
};
};
mongoose.model("SoilLab", SoilLabSchema);
When I try to retrieve the LabReport, I get "this.soilLabs.SoilToLabJSON is not a function". This is how I'm trying to retrieve LabReport.
//labReports.js
...
return Promise.all([
LabReport.find()
.populate("soilLabs")
.exec(),
LabReport.count(query).exec(),
req.payload ? User.findById(req.payload.id) : null,
]).then(function (results) {
var labReports = results[0];
var labReportsCount = results[1];
var user = results[2];
return res.json({
labReports: labReports.map(function (labReport) {
return labReport.toLabToJSON(user); //This cant find SoilToLabJSON
}),
If I remove the .SoilToLabJSON in LabReport.js and just call this.soilLabs, it works but outputs all of the soilLabs data which will become an issue when I have the model completed with more data. I have dug into statics vs methods a little and tried changing it to statics but it didn't work.
I get the soilLabs to populate but not sure why the .SoilToLabJSON method is inaccessible at this point. Do I need to find() or populate the soilLab differently? Is the method incorrect?

labReport.toLabToJSON is passing an array and that was causing the error for me. I simply edited the LabReport.js to the following to take the array and map it to SoilToLabJSON properly.
myTestSoilLabOutput = function (soilLabs) {
var test = soilLabs.map(function (soilLab) {
return soilLab.SoilToLabJSON();
});
return test;
Changed the LabReportSchema.methods.toLabToJSON to:
LabReportSchema.methods.toLabToJSON = function () {
return {
labReport_id: this._id,
testName: this.testName,
soilLabs: myTestSoilLabOutput(this.soilLabs),
};
};

How to update existing object with additional data

The project is created with nodejs and mongoose. What I am trying to do is to update the existing model with addition data (which is a comment, in that case).
This is the model and its methods:
const bugSchema = new Schema({
title: {
type: String,
required: true
},
description: {
type: String,
required: true
},
date: {
type: String,
required: true
},
time: {
type: String,
required: true
},
assignedTo: {
type: String,
required: true
},
assignedBy: {
type: String,
required: true
},
status: {
type: String,
required: true
},
priority: {
type: String,
required: true
},
comments: {
comment:[
{
user:{
type: String,
required: true
},
content: {
type: String,
required: true
}
}
]
}
});
bugSchema.methods.addComment = function(comment){
const username = comment.user;
const content = comment.content;
console.log(comment);
const updatedComments = [...this.comments];
updatedComments.push({
user : username,
content: content
});
this.comments = updatedComments;
return this.save();
};
The controller, which is passing the information from the form:
exports.postComment = (req,res,next) =>{
const bugId = req.body.bugID;
const name = req.session.user.fullName;
const content = req.body.content;
const prod = {name, content};
Bug.findById(bugId).then(bug =>{
return bug.addComment(prod);
})
.then(result =>{
console.log(result);
});
};
I am getting a following error:
(node:3508) UnhandledPromiseRejectionWarning: TypeError: this.comments is not iterable

(node:3508) UnhandledPromiseRejectionWarning: TypeError: this.comments is not iterable
The error indicate you're trying to iterable a type of data which does NOT has that capability.
You can check that printing the type:
console.log(typeof this.comments)
Or even, priting the whole object:
console.log(this.comments)
as you can see, in both cases you're getting an object, not a list (how you spect)
So you can do 2 things:
1- Iterable a list
this.comments is an object but into that object you have the list you want, so just use the list instead.
bugSchema.methods.addComment = function(comment){
const username = comment.user;
const content = comment.content;
console.log(comment);
//const updatedComments = [...this.comments];
const updatedComments = [...this.comments.comment];
updatedComments.push({
user : username,
content: content
});
this.comments = updatedComments;
return this.save();
};
Or you can modify your schema making the comments a list instead of an object
2- comments as list in schema
Define the comments attribute as a list
const bugSchema = new Schema({
title: {
type: String,
required: true
},
description: {
type: String,
required: true
},
...
...,
comments:[
{
user:{
type: String,
required: true
},
content: {
type: String,
required: true
}
}
]
});
And then, try to iterable it as how you been doing
bugSchema.methods.addComment = function(comment){
const username = comment.user;
const content = comment.content;
console.log(comment);
const updatedComments = [...this.comments];
updatedComments.push({
user : username,
content: content
});
this.comments = updatedComments;
return this.save();
};

I am not sure but comments is an object and not an array so you can't push using [...this.comments] and I think it is the comment you want to push?
const updatedComments = [...this.comment];
updatedComments.push({
user : username,
content: content
});
this.comment = updatedComments;

From your schema comments is not an array. you are trying to spread an object into an array. const updatedComments = [...this.comments]; also push works on array.
try to modify your schema definitions by declaring the commentSchema outside the bugSchema.
const commentSchema = new Schema({
user:{
type: String,
required: true
},
content: {
type: String,
required: true
}
})
const bugSchema = new Schema({
comments: {
type: [commentSchema]
}
})
Bug.findByIdAndUpdate(bugId, {$push: {comments: newComment}})

Don't use findByIdAndUpdate Mongoose method, you better use save
it is written here https://mongoosejs.com/docs/tutorials/findoneandupdate.html
The findOneAndUpdate() function in Mongoose has a wide variety of use cases. You should use save() to update documents where possible, but there are some cases where you need to use findOneAndUpdate(). In this tutorial, you'll see how to use findOneAndUpdate(), and learn when you need to use it.
Below a router example
router.put('/items', (req, res) => {
if (!req.body._id || !req.body.title) {
return res.status(501).send({ message: 'Missing parameters, or incorrect parameters' });
}
return itemModel.findOne({ _id: req.body._id }, (err, item) => {
if (err) {
return res.status(500).send({
message: err
});
}
item.title = req.body.title; // <------------- You rewrite what was before stored on title attribute
return item.save((err, item) => { // <------------- You save it, this is not gonna create a new one, except if it doesn't exist already
if (err) {
return res.status(400).send({
message: 'Failed to update item'
});
} else {
return res.status(200).send({
message: 'Item update succesfully',
data: item
});
}
});
});
});

node Sequelize how to write static functions

I have experience in writing statics functions in moongose like
var mongoose =require('mongoose');
var Schema = mongoose.Schema;
var adminSchema = new Schema({
fullname : String,
number : Number,
email: String,
auth : {
username: String,
password : String,
salt: String
}
});
adminSchema.statics.usernameInUse = function (username, callback) {
this.findOne({ 'auth.username' : username }, function (err, doc) {
if (err) callback(err);
else if (doc) callback(null, true);
else callback(null, false);
});
};
here usernameInUse is the function I wana write but using sequelize for mysql database
my model
/*
This module is attendant_user table model.
It will store attendants accounts details.
*/
"use strict";
module.exports = function(sequelize, DataTypes) {
var AttendantUser = sequelize.define('AttendantUser', {
username : {
type : DataTypes.STRING,
allowNull : false,
validate : {
isAlpha : true
}
},{
freezeTableName : true,
paranoid : true
});
return AttendantUser;
};
How to add statics function here..??

Well, you can easily use Expansion of models
var User = sequelize.define('user', { firstname: Sequelize.STRING });
// Adding a class level method
User.classLevelMethod = function() {
return 'foo';
};
// Adding an instance level method
User.prototype.instanceLevelMethod = function() {
return 'bar';
};
OR in some cases you may use getter and setter on your models. See the docs:
A) Defining as part of a property:
var Employee = sequelize.define('employee', {
name: {
type : Sequelize.STRING,
allowNull: false,
get : function() {
var title = this.getDataValue('title');
// 'this' allows you to access attributes of the instance
return this.getDataValue('name') + ' (' + title + ')';
},
},
title: {
type : Sequelize.STRING,
allowNull: false,
set : function(val) {
this.setDataValue('title', val.toUpperCase());
}
}
});
Employee
.create({ name: 'John Doe', title: 'senior engineer' })
.then(function(employee) {
console.log(employee.get('name')); // John Doe (SENIOR ENGINEER)
console.log(employee.get('title')); // SENIOR ENGINEER
})
B) Defining as part of the model:
var Foo = sequelize.define('foo', {
firstname: Sequelize.STRING,
lastname: Sequelize.STRING
}, {
getterMethods : {
fullName : function() { return this.firstname + ' ' + this.lastname }
},
setterMethods : {
fullName : function(value) {
var names = value.split(' ');
this.setDataValue('firstname', names.slice(0, -1).join(' '));
this.setDataValue('lastname', names.slice(-1).join(' '));
},
}
});
Hope it helps.

AttendantUser.usernameInUse = function (username, callback) {
...
};
return AttendantUser;

mongoose findOneAndUpdate deletes nested vars

In my express/mongoose code when I update a nested var it deletes any other nested vars in the object I didn't update?
My schema:
var MySchema = new Schema({
active: { type: Boolean, required: true, default: true },
myvar: {
useDefault: { type: Boolean, required: true },
custom: { type: String },
default: { type: String }
}
});
My express middleware update function:
var updateData = req.body;
MySchema.findOneAndUpdate({ active: true }, updateData, function(err, myschema) {
if (err) throw err;
if (!myschema) { response(403, { success:false, message: "myschema not updated." }, res); }
// success
response(200, { success:true, message: "myschema updated." }, res);
});
The record initially look like this:
{
"myvar": {
"useDefault": true,
"custom": "some custom var",
"default": "some value"
}
}
When I submit an update to say the myvar.useDefault value the record ends up like this:
{
"myvar": {
"useDefault": false
}
}
Can anyone advise how to update only the targeted var and leave any other vars as they were?

The answer was to convert the response.body object to dot notation and pass that modified object to mongoose findOneAndUpdate. Thanks to #btkostner on Gitter for the answer and his toDot function. Here is the relevant bits of code:
function(req, res) {
// convert response to dot notation so objects retain other values
var dotData = toDot(req.body, '.');
MySchema.findOneAndUpdate({ active: true }, dotData, function(err, myschema) {
...
}
// author: #btcostner
function toDot (obj, div, pre) {
if (typeof obj !== 'object') {
throw new Error('toDot requires a valid object');
}
if (pre != null) {
pre = pre + div;
} else {
pre = '';
}
var iteration = {};
Object.keys(obj).forEach(function(key) {
if (_.isPlainObject(obj[key])) {
Object.assign(iteration, _this.toDot(obj[key], div, pre + key));
} else {
iteration[pre + key] = obj[key];
}
});
return iteration;
};
NOTE: I had to convert the toDot() function to ES5 for my project, here is the original ES6 version: github.com/elementary/houston/blob/master/src/lib/helpers/dotNotation.js