What exactly is "data" that is passed to responses? - sails.js

I'm writing a custom response that takes data as an input, and I am finding strange properties being added, namely:
add: [Function: add],
remove: [Function: remove]
When I log out some example data, I get:
[ { books:
[ { id: 1,
title: 'A Game of Thrones',
createdAt: '2015-08-04T04:53:38.043Z',
updatedAt: '2015-08-04T04:53:38.080Z',
author: 1 } ],
id: 1,
name: 'George R. R. Martin',
createdAt: '2015-08-04T04:53:38.040Z',
updatedAt: '2015-08-04T04:53:38.073Z' },
{ books:
[ { id: 2,
title: 'Ender\'s Game',
createdAt: '2015-08-04T04:53:38.043Z',
updatedAt: '2015-08-04T04:53:38.080Z',
author: 2 },
{ id: 3,
title: 'Speaker for the Dead',
createdAt: '2015-08-04T04:53:38.043Z',
updatedAt: '2015-08-04T04:53:38.081Z',
author: 2 } ],
id: 2,
name: 'Orson Scott Card',
createdAt: '2015-08-04T04:53:38.042Z',
updatedAt: '2015-08-04T04:53:38.074Z' } ]
Which looks innocent enough, but results in the strange add and remove functions when I use a custom serializer on it. If I take this data and hard-code it straight into the serializer, those are not present. Apparently something is lurking inside of data that's not being printed to the console.
So, what is data?
Edit: So, I'm still not quite sure what other magical properties live in here, but:
Object.keys(data[0].books))
reveals
[ '0', 'add', 'remove' ]
Which is where those are coming from. Why is this included in the data passed to custom responses? And what else might be hiding in there...
More importantly, how do I strip this gunk out and make data a normal object?

JSON.parse(JSON.stringify(data));
That cleans it up nicely, though it feels like a hack. (Actually, it's definitely a hack.)

I assume your data attribute is returned by a database query. e.g.:
Model.find(...).exec(function (err, data) { ... });
But what are these .add() and .remove() methods?
Here is what you can find in the docs:
For the most part, records are just plain old JavaScript objects (aka POJOs). However they do have a few protected (non-enumerable) methods for formatting their wrapped data, as well as a special method (.save()) for persisting programmatic changes to the database.
We can go deeper:
"collection" associations, on the other hand, do have a couple of special (non-enumerable) methods for associating and disassociating linked records. However, .save() must still be called on the original record in order for changes to be persisted to the database.
orders[1].buyers.add({ name: 'Jon Snow' });
orders[1].save(function (err) { ... });
So these methods (.add(), .remove(), .save()) are useful if you play with "collection" associations.
How to remove them?
You'll need to use .toObject() which returns a cloned model instance stripped of all instance methods.
You might want to use .toJSON() that also returns a cloned model instance. This one however includes all instance methods.

Related

Accessing nested documents within nested documents

I'm having a problem that is really bugging me. I don't even want to use this solution I don't think but I want to know if there is one.
I was creating a comment section with mongodb and mongoose and keeping the comments attached to the resource like this:
const MovieSchema = new mongoose.Schema({
movieTitle: {type: String, text: true},
year: Number,
imdb: String,
comments: [{
date: Date,
body: String
}]
})
When editing the comments body I understood I could access a nested document like this:
const query = {
imdb: req.body.movie.imdb,
"comments._id": new ObjectId(req.body.editedComment._id)
}
const update = {
$set: {
"comments.$.body": req.body.newComment
}
}
Movie.findOneAndUpdate(query, update, function(err, movie) {
//do stuff
})
I then wanted to roll out a first level reply to comments, where every reply to a comment or to another reply just appeared as an array of replies for the top level comment (sort of like Facebook, not like reddit). At first I wanted to keep the replies attached to the comments just as I had kept the comments attachted to the resource. So the schema would look something like this:
const MovieSchema = new mongoose.Schema({
movieTitle: {type: String, text: true},
year: Number,
imdb: String,
comments: [{
date: Date,
body: String,
replies: [{
date: Date,
body: String
}]
}]
})
My question is how would you go about accessing a nested nested document. For instance if I wanted to edit a reply it doesn't seem I can use two $ symbols. So how would I do this in mongodb, and is this even possible?
I'm pretty sure I'm going to make Comments have its own model to simplify things but I still want to know if this is possible because it seems like a pretty big drawback of mongodb if not. On the other hand I'd feel pretty stupid using mongodb if I didn't figure out how to edit a nested nested document...
according to this issue: https://jira.mongodb.org/browse/SERVER-27089
updating nested-nested elements can be done this way:
parent.update({},
{$set: {“children.$[i].children.$[j].d”: nuValue}},
{ arrayFilters: [{ “i._id”: childId}, { “j._id”: grandchildId }] });
this is included in MongoDB 3.5.12 development version, in the MongoDB 3.6 production version.
according to https://github.com/Automattic/mongoose/issues/5986#issuecomment-358065800 it's supposed to be supported in mongoose 5+
if you're using an older mongodb or mongoose versions, there are 2 options:
find parent, edit result's grandchild, save parent.
const result = await parent.findById(parentId);
const grandchild = result.children.find(child => child._id.equals(childId))
.children.find(grandchild => grandchild._id.equals(grandchildId));
grandchild.field = value;
parent.save();
know granchild's index "somehow", findByIdAndUpdate parent with:
parent.findByIdAndUpdate(id,
{ $set: { [`children.$.children.${index}.field`]: value }});

Using objects as options in Autoform

In my Stacks schema i have a dimensions property defined as such:
dimensions: {
type: [String],
autoform: {
options: function() {
return Dimensions.find().map(function(d) {
return { label: d.name, value: d._id };
});
}
}
}
This works really well, and using Mongol I'm able to see that an attempt to insert data through the form worked well (in this case I chose two dimensions to insert)
However what I really what is data that stores the actual dimension object rather than it's key. Something like this:
[
To try to achieve this I changed type:[String] to type:[DimensionSchema] and value: d._id to value: d. The thinking here that I'm telling the form that I am expecting an object and am now returning the object itself.
However when I run this I get the following error in my console.
Meteor does not currently support objects other than ObjectID as ids
Poking around a little bit and changing type:[DimensionSchema] to type: DimensionSchema I see some new errors in the console (presumably they get buried when the type is an array
So it appears that autoform is trying to take the value I want stored in the database and trying to use that as an id. Any thoughts on the best way to do this?.
For reference here is my DimensionSchema
export const DimensionSchema = new SimpleSchema({
name: {
type: String,
label: "Name"
},
value: {
type: Number,
decimal: true,
label: "Value",
min: 0
},
tol: {
type: Number,
decimal: true,
label: "Tolerance"
},
author: {
type: String,
label: "Author",
autoValue: function() {
return this.userId
},
autoform: {
type: "hidden"
}
},
createdAt: {
type: Date,
label: "Created At",
autoValue: function() {
return new Date()
},
autoform: {
type: "hidden"
}
}
})
According to my experience and aldeed himself in this issue, autoform is not very friendly to fields that are arrays of objects.
I would generally advise against embedding this data in such a way. It makes the data more difficult to maintain in case a dimension document is modified in the future.
alternatives
You can use a package like publish-composite to create a reactive-join in a publication, while only embedding the _ids in the stack documents.
You can use something like the PeerDB package to do the de-normalization for you, which will also update nested documents for you. Take into account that it comes with a learning curve.
Manually code the specific forms that cannot be easily created with AutoForm. This gives you maximum control and sometimes it is easier than all of the tinkering.
if you insist on using AutoForm
While it may be possible to create a custom input type (via AutoForm.addInputType()), I would not recommend it. It would require you to create a template and modify the data in its valueOut method and it would not be very easy to generate edit forms.
Since this is a specific use case, I believe that the best approach is to use a slightly modified schema and handle the data in a Meteor method.
Define a schema with an array of strings:
export const StacksSchemaSubset = new SimpleSchema({
desc: {
type: String
},
...
dimensions: {
type: [String],
autoform: {
options: function() {
return Dimensions.find().map(function(d) {
return { label: d.name, value: d._id };
});
}
}
}
});
Then, render a quickForm, specifying a schema and a method:
<template name="StacksForm">
{{> quickForm
schema=reducedSchema
id="createStack"
type="method"
meteormethod="createStack"
omitFields="createdAt"
}}
</template>
And define the appropriate helper to deliver the schema:
Template.StacksForm.helpers({
reducedSchema() {
return StacksSchemaSubset;
}
});
And on the server, define the method and mutate the data before inserting.
Meteor.methods({
createStack(data) {
// validate data
const dims = Dimensions.find({_id: {$in: data.dimensions}}).fetch(); // specify fields if needed
data.dimensions = dims;
Stacks.insert(data);
}
});
The only thing i can advise at this moment (if the values doesnt support object type), is to convert object into string(i.e. serialized string) and set that as the value for "dimensions" key (instead of object) and save that into DB.
And while getting back from db, just unserialize that value (string) into object again.

Create Both Parent/Child Associated Record in Sailsjs

I'm having a hard time trying to figure out if sails/waterline even does this.
(so an adequate answer would simply be if this is possible or not, I have been reading docs, looking through github issues and looking through code, but still not sure)
I have a one to one association setup where an 'account' has a 'contact'
I'm trying to create a contact within sails blueprints (so basically just using the create() method)
account =
{ name: 'Corp'
contact:{
firstName: 'Bob',
lastName: 'Jones'
}
}
so should Account.create(account).exec() create the account and the associated contact? Because I'm getting the following error
TypeError: Cannot convert null to object
My model is setup like so
account.js
module.exports = {
migrate: 'safe',
tableName: 'accounts',
autoPK: false,
attributes: {
id: {
type: 'INTEGER',
primaryKey: true,
autoIncrement: true
},
contactId: 'INTEGER',
name: {type: 'STRING', maxLength: 100},
contact: {
model: 'contact',
columnName:'contactId'
}
}
};
I'm using sails 10.0-rc8 / waterline 10.0-rc15
Creating an associated instance at the same time as its parent (aka "nested create") should work, but it's tricky to get things just right when you're dealing with a legacy database. In your case, the contactId attribute declaration is probably causing the issue, since Waterline expects the foreign key field to be implicit, not explicit. Try removing:
contactId: 'INTEGER',
entirely and see where that gets you.
After some research I found out that as of version 0.10.0-rc15 of waterline you can NOT have a customized foreign keys. In the above model if I change the "contactId" column to just "contact" (basically make it look exactly like it does in the docs. Then it works.
I made the following bug report
https://github.com/balderdashy/waterline/issues/529

Building a dynamic mongo query for meteor

I'm building an app that has clickable 'filters'; I'm creating a list of objects(?) that I want to pass to a mongo 'find', so that I can pull out listings if selected attributes match a certain score.
My data is structured like this (a snippet):
name: 'Entry One',
location: {
type: 'Point',
coordinates: [-5.654182,50.045414]
},
dogs: {
score: '1',
when: 'seasonal',
desc: 'Dogs allowed from October to April'
},
lifeguard: {
score: '1',
when: 'seasonal',
desc: 'A lifeguard hut is manned between April and October',
times: ''
},
cafe: {
score: '1',
name:'Lovely cafe',
open:'seasonal'
}, ...
My search variable is a list of objects (I think?) that I assign to a session variable. If I output this session var ('searchString') via JSON.stringify, it looks like this:
{"cafe":{"score":"1"},"dogs":{"score":"1"}}
I'd like to pass this to my mongo find so that it only lists entries that match these scores on these attributes, but it's returning zero results. Do I need to somehow make this an $and query?
Currently it looks like this:
Beaches.find(searchString);
Unfortunately as soon as I drop searchString into the find, I get zero results even if it's empty {}. (When it's just a find() the entries list fine, so the data itself is ok)
What am I doing wrong? I'm relatively new to mongo/meteor, so I apologise in advance if it's something stupidly obvious!
Don't stringify the query. Flatten the object instead. Example:
Beaches.find({
"cafe.score": 1,
"dogs.score": 1,
});

Does Moongoose 3.8.8 support $position operator?

Does Moongoose 3.8.8 (the lastest version) support $position (http://docs.mongodb.org/manual/reference/operator/update/position/) operator from MongoDB 2.6.0?
In the following code example the new elements is inserted in the end of the array userActivity.activities:
model:
var userActivity = new schema({
userId: {type:String, required:true, unique:true},
activities: [activity]
});
var activity = new schema({
act: {type: Number, required:true},
});
query:
var activity = { act: 1 };
model.userActivity.update(
{ _id: dbact._id },
{ $push: { activities: {
$each: [ activity ],
$position: 0
}
}
},
function (err, numAffected) {
if (!err) {
// do something
}
});
This actually doesn't matter and never matters for any "framework" implementation and I do not mind explaining why.
Every single "framework" ( such as Mongoose, Mongoid, Doctrine, MongoEngine, etc, etc, etc ) are all basically built upon a basic "driver" implementation that has in most cases been developedby the MongoDB staff themselves. So the basic functionality is always ther even if you need to "delve" down to a level in order to use those "native" methods.
So here would be the native usage example in this case:
List.collection.update(
{},
{ "$push": {
"list": {
"$each": [ 1, 2, 3 ],
"$position": 0 }
}
},function(err,NumAffected) {
console.log("done");
});
Note the "collection" method used from the model, which is getting the "raw" collection details from the driver. So you are using it's method and not some "wrapped" method that may be doing additional processing.
The next and most basic reason is if you cannot find the method and application of the operators that you need the here is a simple fact.
Every single operation as used by the methods in every framework and basic driver method is essentially a call to the "runCommand" method in the basic API. So since that basic call is available everywhere ( in some form or another, because it has to be ), then you can do everything that you find advertised on the MongoDB site with every language implementation on any framework.
But the short call to your particular request is, since this is not actually a method call but is simply part of the BSON arguments as passed in, then of course there is no restriction by a particular language driver to actually use this.
So you can use these new argument without of course updating to the most recent version. But you probably will get some nice methods to do so if you actually do.
Yes, you should be able to use it directly as Mongoose will pass through the update clause:
Model.update(
query, /* match the document */
{ $push:
{ yourArrayField:
{
$each: [ 1, 2, 3 ],
$position: 0
}
}
}, function (err, res) { /* callback */ });
The above would insert the values 1, 2, 3 at the front of the array named yourArrayField.
As it's just a pass-through, you'll need to make sure it works with the server version that you're connecting the client to.