Develop Reference

Mongoose cast to ObjectID failed for value... but why

I know what the problem is, but can't figure out why it is happening. I have a simple recipe app using express and mongoose. User passes in recipe info via form and is saved to database via mongoose methods. This part seems to work perfectly and when I console.log using test data, I see that the following data is saved:
{
ingredients: [ 'peanut butter', 'jelly', 'bread' ],
_id: 5e47d564f775ce247052d01c,
name: 'pb jelly sammich',
author: 'rob',
oneLiner: 'classic pb jelly sammich',
image: 'picofpbsammich here',
method: 'add all the ingredients together and boom! pb jelly sammich.',
__v: 0
}
(This is also what shows when I check mongo db using db.recipes.find() and also what displays when I pass in the object to my ejs show template.
However, when I access my show route via get request, I get a long error message using the above test data. Here is they key part of the error message:
'Cast to ObjectId failed for value "picofpbsammich here" at path "_id" for model "Recipes"',
I understand what the problem is, but baffled as to why it is happening. Here is my show route:
app.get("/recipes/:id", function (req, res) {
console.log(req.params.id)
Recipe.findById(req.params.id, function (err, foundRecipe) {
if (err) {
console.log(err);
} else {
res.render("show", { recipe: foundRecipe });
}
})
})
console logging the req.params.id as shown above, prints the following:
5e47d564f775ce247052d01c
picofpbsammich here
The first line is the correct ID, the second is obviously not and the cause of the problem, but I have no idea where that could be coming from :S Why would req.params.id be pulling the VALUE of a property that is named something completely different?
I'm new to mongoose so it's probably something silly I'm doing and any explanations appreciated.
Here is the model:
var mongoose = require("mongoose");
let recipeSchema = new mongoose.Schema({
name: {
type: String,
required: true
},
author: String,
oneLiner: String,
ingredients: [String],
image: String,
method: String
})
module.exports = mongoose.model("Recipes", recipeSchema)

You posted the following code:
app.get("/recipes/:id", function (req, res) {
console.log(req.params.id)
Recipe.findById(req.params.id, function (err, foundRecipe) {
if (err) {
console.log(err);
} else {
res.render("show", { recipe: foundRecipe });
}
})
})
And you mention that in the console.log you receive:
5e47d564f775ce247052d01c
picofpbsammich here
Followed by the exception being logged:
'Cast to ObjectId failed for value "picofpbsammich here" at path "_id"
for model "Recipes"',
Makes me logically assume that you are making two requests, one of which the id is not valid, being:
picofpbsammich here
Mongoose is not able to cast this value to an ObjectId, hence you get the exception, which makes sense imo.

POSTING an array of objects to node.js/save to database using mongoose

I have a ReactJS form, in which you can dynamically add form "parts"(sections with form input). Here's an example of what I mean by "parts":
<div>
<input placeholder="Author" />
<input placeholder="Age" />
<input placeholder="Amount of books written" />
</div>
Something like this. You can add as many of these divs as you like.
I'm saving the values of these inputs in the state, which gives me a nested array like so:
this.state = {
formdata : [
{author: "somebody", age: 34, books: 0},
{author: "somebody else", age: 100, books: 1}
]
}
Right now I'm use axios post to post the data to node.js with express. This is my post function:
handleSubmit(e) {
axios.post('receivedata',
querystring.stringify({
formdata : this.state.formdata
}), {
headers : {"Content-Type": "application/x-www-form-urlencoded"}
}
)
.then(function (response) {
console.log(response);
})
.catch(function (error) {
console.log(error);
});
}
And this is the mongoose schema that I use:
var EntrySchema = new mongoose.Schema({
formdata: [{type:String}],
updated_at: {type: Date, default: Date.now}
});
and this is how I (try to) send the data to my database:
router.post("/", function(req, res) {
newEntry.formdata = req.body.formdata;
newEntry.save(function (err) {
if(err)
res.send(err);
res.send("Entry added successfully!");
});
});
That doesn't work though and when I check the database, I receive an array with an empty string like so: formdata:[{""}]
I think the problem is with how the schema is set up, since, when I do console.log(this.state.formdata) it correctly returns the data. My next guess would be that axios is not able to send nested array, but after some research I found that that's not the case so I'm assuming that there's a special way to define nested arrays in the mongoose schema? How would I go about that?
Edit: I was thinking that maybe I could do something along the lines of:
var EntrySchema = new mongoose.Schema({
formdata: [{
author: String,
age: Number,
books: Number
}],
updated_at: {type: Date, default: Date.now}
});
I tried this and it doesn't work either. Now, I don't know if I'm on the right track or how else to do this.
I also tried changing the Content-Type in the header to "application/ json", as suggested in another answer. Once again, it didn't work.
Any help is appreciated.

Okay so after some playing around I figured it out: I used querystring.stringify() before, after changing it to JSON.stringify() it worked perfectly for me.

Express returning "User is not authorized" when modifying object from another user

I have a Classroom model that looks like this:
/**
* Classroom Schema
*/
var ClassroomSchema = new Schema({
created: {
type: Date,
default: Date.now
},
participants: [{
type: Schema.ObjectId,
ref: 'User'
}],
lesson: {
type: Schema.ObjectId,
ref: 'Lesson',
required: 'Define a lesson for this classroom',
},
user: {
type: Schema.ObjectId,
ref: 'User'
},
currentTaskIndex: {
type: Number,
default: 0
},
});
As you can see, the model keeps a reference to the user that have created the Classroom (User) and it also has many participants (more Users).
I'm trying to add the functionality to allow other Users (not the creator of the Classroom) to join the Classroom by sending a PUT request to the classroom API with a new User in the participants field. However, since the User sending the request is not the one who created the object, Express is returning a 403 (Forbidden):
exports.hasAuthorization = function(req, res, next) {
if (req.classroom.user.id !== req.user.id) {
return res.status(403).send('User is not authorized');
}
next();
};
What's the best approach/pattern to solve this allowing Users to join Classrooms created by another User but not to do other actions like deleting the object. Other fields might be updated by another participants, like the currentTaskIndex.
Thanks for your help!

You could add a 'master' or 'admin' field to your classroom, and store the Creator's userId in it.
Then you can allow the delete/modify, etc actions only for the user who is master of this particular classroom, while letting everyone in.

Understanding Mongoose sub documents

I'm learning Mongoose. At the moment I did few nice things but I really don't understand exactly how Mongoose manage relationships between Schemas.
So, easy thing (I hope): I'm doing a classic exercise (by my self because I cannot find a good tutorial that create more than 2 Schemas) with 3 Schemas:
User, Post, Comment.
User can create many Post;
User can create many Comment;
Post belong to User.
Comment belong to User and Post.
I don't think it is something very hard uhu?
At the moment I can manage very well Relation between User and Post. My Unit test return exactly what I need, at the moment I'm using mongo-relation and I don't know if it is a good idea...
it('Use should create a Post', function(done) {
User.findOne({ email: 'test#email.com' }, function(err, user) {
var post = {
title: 'Post title',
message: 'Post message',
comments: []
};
user.posts.create(post, function(err, user, post) {
if (err) return done(err);
user.posts[0].should.equal(post._id);
post.author.should.equal(user._id);
// etc...
done();
});
});
});
The problem now is to create a comment.
I can not create a comment that refere to the Post and to the User together.
I did something like that and works but when I perform a remove it is removed only from the Post and not from the User.
So I think there is something I miss or I still need to study to enhance it.
it('User should add a Comment to a Post', function(done) {
User.findOne({ email: 'test#email.com' }, function(err, user) {
if (err) return done(err);
var comment = new Comment({
author: user._id,
message: 'Post comment'
});
Post.findOne({ title: 'Post title'}, function(err, post) {
if (err) return done(err);
post.comments.append(comment, function(err, comment) {
if (err) return done(err);
post.save(function(err) {
if (err) return done(err);
});
comment.author.should.equal(user._id);
post.comments.should.have.length(1);
// etc...
done();
});
});
});
});
As you can see the code is not very "nice to see" but it works fine in terms of creations.
The problem is when I remove a Comment. It seems like something is wrong.
Here is the Model relationship:
// User Schema
var userSchema = new mongoose.Schema({
// [...],
posts: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Post' }],
comments: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Comment' }],
});
// Post Schema
var postSchema = new mongoose.Schema({
author: { type: mongoose.Schema.ObjectId, ref: 'User', refPath: 'posts' },
title: String,
message: String,
comments: [{ type: mongoose.Schema.ObjectId, ref: 'Comment' }]
});
// Comment Schema
var commentSchema = new mongoose.Schema({
author: { type: mongoose.Schema.ObjectId, ref: 'User', refPath: 'comments' },
post: { type: mongoose.Schema.ObjectId, ref: 'Post', refPath: 'comments' },
message: String
});
I really hope in your help to understand all this.
It will be nice also a simple good tutorial about it.

I think you are misunderstanding subdocuments. The way you have your schema setup you are creating references to documents in other collections.
For example if you create a post, in the database it will look like this:
{
"author": ObjectId(123),
"title": "post title",
"message": "post message",
"comments": [ObjectId(456), ObjectId(789)]
}
Notice the "author" field just contains the ID of the author who created it. It does not actually contain the document itself.
When you read the document from the DB you can use the mongoose 'populate' functionality to also fetch the referred to document.
Ex (with populate):
Post
.findOne({ title: 'Post title'})
.populate('author', function(err, post) {
// this will print out the whole user object
console.log(post.author)
});
Ex (no populate):
Post
.findOne({ title: 'Post title'}, function(err, post) {
// this will print out the object ID
console.log(post.author)
});
Subdocuments:
You can actually nest data in the DB using subdocuments, the schema would look slightly different:
var postSchema = new mongoose.Schema({
author: { userSchema },
title: String,
message: String,
comments: [commentSchema]
});
When saving a post the user document would be nested inside the post:
{
"author": {
"name": "user name",
"email": "test#email.com"
...
},
"title": "post title",
"message": "post message",
"comments": [{
"message": "test",
...
}, {
"message": "test",
...
}]
}
Subdocuments can be useful in mongo, but probably not for this case because you would be duplicating all of the user data in every post.
Removing documents
When you issue a Comment.remove(id) the comment will be removed but it will not affect the other documents referring to it. So you will then have a Post and a User with a comment ID that does not exist. You need to manually clean up the comment ID from the other documents. You could use the mongoose pre remove event to do this. http://mongoosejs.com/docs/middleware.html
commentSchema.pre('remove', function (next) {
// this refers to the document being removed
var userId = this.author;
var postId = this.post;
User.findById(userId, function(err, user) {
// remove comment id from users.comments here;
Post.findById(postId, function(err, post) {
// remove comment id from post.comments;
next();
});
});
});

Access user email address in Meteor JS app

I am building an app using Meteor and need to access the stored email address of a logged-in user.
I am currently using:
var userObj = Meteor.user();
console.log(userObj);
to access the user. However, I am only able to access the id. The email address is stored in a nested object that looks like this:
[Object {address="address#gmail.com", verified=false}]
I have tried various ways to traverse the JSON object but can't figure out how to access the value I need.

Meteor.user().emails[0].address works for me.
Here's what the doc says:
By default the server publishes username, emails, and profile. See
Meteor.users for more on the fields used in user documents.
Example user document:
{
_id: "bbca5d6a-2156-41c4-89da-0329e8c99a4f", // Meteor.userId()
username: "cool_kid_13", // unique name
emails: [
// each email address can only belong to one user.
{ address: "cool#example.com", verified: true },
{ address: "another#different.com", verified: false }
],
createdAt: 1349761684042,
profile: {
// The profile is writable by the user by default.
name: "Joe Schmoe"
},
services: {
facebook: {
id: "709050", // facebook id
accessToken: "AAACCgdX7G2...AbV9AZDZD"
},
resume: {
loginTokens: [
{ token: "97e8c205-c7e4-47c9-9bea-8e2ccc0694cd",
when: 1349761684048 }
]
}
}
}

You don't specify how you are authenticating users. For example, if you were using Google authentication only, the email address would be found only in
Meteor.user().services.google.email
So, it depends.

Try this:
Meteor.user().emails[0].address
Regards,