I found this example to use the Node API to apply filters to related models, but I was wondering if it was possible to achieve the same result using REST?
Node Example:
Post.find({
include: {
relation: 'owner', // include the owner object
scope: { // further filter the owner object
fields: ['username', 'email'], // only show two fields
include: { // include orders for the owner
relation: 'orders',
scope: {
where: {orderId: 5} // only select order with id 5
}
}
}
}
}, function() { ... });
The closest version of a REST url I can get to work is:
...?filter[include][owners][orders]
Is it possible to create a REST url that behaves the same way as the above Node example, by limiting the results based on a related model filter... in this case orders?
I have this functions so when I call the Hdates/coming REST API it shows the events with date greater than today and also includes the venues... Hope it helps.
Hdate.coming = function(cb) {
Hdate.find({
where : {
event_date :{gt: Date.now()}
},
include : {
relation: 'event',
scope : {
include: {
relation: 'venue'
}
}
}
}, cb);
};
Hdate.setup = function() {
Hdate.base.setup.apply(this, arguments);
this.remoteMethod('coming', {
description: 'Find Coming Events by Date',
returns: {arg: 'events', root: true},
http: { verb: 'GET' }
});
};
Hdate.setup();
Related
Every tutorial I have found thus far has achieved pagination in GraphQL via Apollo, Relay, or some other magic framework. I was hoping to find answers in similar asked questions here but they don't exist. I understand how to setup the queries but I'm unclear as to how I would implement the resolvers.
Could someone point me in the right direction? I am using mongoose/MongoDB and ES5, if that helps.
EDIT: It's worth noting that the official site for learning GraphQL doesn't have an entry on pagination if you choose to use graphql.js.
EDIT 2: I love that there are some people who vote to close questions before doing their research whereas others use their knowledge to help others. You can't stop progress, no matter how hard you try. (:
Pagination in vanilla GraphQL
// Pagination argument type to represent offset and limit arguments
const PaginationArgType = new GraphQLInputObjectType({
name: 'PaginationArg',
fields: {
offset: {
type: GraphQLInt,
description: "Skip n rows."
},
first: {
type: GraphQLInt,
description: "First n rows after the offset."
},
}
})
// Function to generate paginated list type for a GraphQLObjectType (for representing paginated response)
// Accepts a GraphQLObjectType as an argument and gives a paginated list type to represent paginated response.
const PaginatedListType = (ItemType) => new GraphQLObjectType({
name: 'Paginated' + ItemType, // So that a new type name is generated for each item type, when we want paginated types for different types (eg. for Person, Book, etc.). Otherwise, GraphQL would complain saying that duplicate type is created when there are multiple paginated types.
fields: {
count: { type: GraphQLInt },
items: { type: new GraphQLList(ItemType) }
}
})
// Type for representing a single item. eg. Person
const PersonType = new GraphQLObjectType({
name: 'Person',
fields: {
id: { type: new GraphQLNonNull(GraphQLID) },
name: { type: GraphQLString },
}
})
// Query type which accepts pagination arguments with resolve function
const PersonQueryTypes = {
people: {
type: PaginatedListType(PersonType),
args: {
pagination: {
type: PaginationArgType,
defaultValue: { offset: 0, first: 10 }
},
},
resolve: (_, args) => {
const { offset, first } = args.pagination
// Call MongoDB/Mongoose functions to fetch data and count from database here.
return {
items: People.find().skip(offset).limit(first).exec()
count: People.count()
}
},
}
}
// Root query type
const QueryType = new GraphQLObjectType({
name: 'QueryType',
fields: {
...PersonQueryTypes,
},
});
// GraphQL Schema
const Schema = new GraphQLSchema({
query: QueryType
});
and when querying:
{
people(pagination: {offset: 0, first: 10}) {
items {
id
name
}
count
}
}
Have created a launchpad here.
There's a number of ways you could implement pagination, but here's two simple example resolvers that use Mongoose to get you started:
Simple pagination using limit and skip:
(obj, { pageSize = 10, page = 0 }) => {
return Foo.find()
.skip(page*pageSize)
.limit(pageSize)
.exec()
}
Using _id as a cursor:
(obj, { pageSize = 10, cursor }) => {
const params = cursor ? {'_id': {'$gt': cursor}} : undefined
return Foo.find(params).limit(pageSize).exec()
}
I'm using sails.js for a project and everything is going fine so far. Except that I don't know how to have an optional association between my two models. If I don't specify one, then if I use populate() it takes the first one available.
I have those two models:
// Book.js
module.exports = {
attributes: {
title: 'string',
serie: { model: 'serie' }
},
};
// Serie.js
module.exports = {
attributes: {
name: 'string',
books: { collection: 'book', via: 'serie' }
}
};
If I do this:
$ sails console
> Book.create({title: "Title"}).exec(function(err, book) {
Book.findOne({id: book.id }).populateAll().exec(function(err, book) {
console.log(book);
});
});
I get this:
{
serie: { name: 'Previously inserted serie' },
title: 'Title',
id: '55d6230122e3b1e70d877351'
}
Why isn't serie empty ? When inserting the book, I didn't specify any serie but it is still linked to a random one.
It was actually a bug from the sails-mongo adapter. I made a pull request that fixes it.
I am trying to give a default association from a user to a pet, whenever a new User created.
Model:: User.js
var User = {
attributes: {
name: {type: 'string'},
// Add a One Way Relation to pet model
pets: {
collection: 'pet'
},
},
/*** This did not work ***/
beforeCreate: function (user, next) {
var defaultPet = {name: 'Default Pet 1'};
Pet.find(defaultPet).exec(function(err, pet) {
user.name = "BEFORECREATE",
user.pets = pet[0].id;
next();
});
},
}
module.exports = User;
However when a new record is created the user.pet is [ ], but user.name is changed to "BEFORECREATE".
How do I get user.pets = [{name: 'Default Pet 1'}] automatically for the new user created?
Or is there a better place for setting such defaults?
----- UPDATE: More info
I am using sails-disk currently.
Model: Pet.js
module.exports = {
attributes: {
name: {
type: 'string',
required: true
}
}
};
You can't add associations to a model in a lifecycle callback like beforeCreate. Currently, Waterline looks for and processes "nested models" like these before lifecycle callbacks run, so by the time beforeCreate is called it's too late. The simplest solution would be to create a User.createUser class method that wraps the logic you want:
createUser: function(data, cb) {
// If there are already pets specified, just use those
if (data.pets) {return User.create(data).exec(cb);}
// Otherwise look up the default pet
Pet.findOne({name:"Default Pet 1"}).exec(function(err,pet) {
// Return in case of error
if (err) {return cb(err);}
// Assuming the default pet exists, attach it
if (pet) {
console.log("SETTING DEFAULT PET", pet.id);
data.pets = [pet.id];
}
// Create the pet
return User.create(data).exec(cb);
});
}
A few notes:
In your example you were setting pets directly to an ID, but since it's a collection you must set it to an array.
If you're using the sails-disk adapter, you'll need to set schema: true in your model for this to work.
The new User model you get back will not be populated; you'll have to do a find with a populate('pets') with the new User ID to get the pet data attached.
Let's say I have an Invoice model in SailsJS. It has 2 date attributes: issuedAt and dueAt. How can I create a custom validation rule that check that the due date is equal or greater than the issued date?
I tried creating a custom rule, but it seems I cannot access other properties inside a rule.
module.exports = {
schema: true,
types: {
duedate: function(dueAt) {
return dueAt >= this.issuedAt // Doesn't work, "this" refers to the function, not the model instance
}
},
attributes: {
issuedAt: {
type: 'date'
},
dueAt: {
type: 'date',
duedate: true
}
}
};
I hope you found a solution now, but for those interested to a good way to handle this i will explain my way to do it.
Unfortunatly as you said you can't access others record attributes in attribute customs validation function.
#Paweł Wszoła give you the right direction and here is a complete solution working for Sails#1.0.2 :
// Get buildUsageError to construct waterline usage error
const buildUsageError = require('waterline/lib/waterline/utils/query/private/build-usage-error');
module.exports = {
schema: true,
attributes: {
issuedAt: {
type: 'ref',
columnType: 'timestamp'
},
dueAt: {
type: 'ref',
columnType: 'timestamp'
}
},
beforeCreate: (record, next) => {
// This function is called before record creation so if callback method "next" is called with an attribute the creation will be canceled and the error will be returned
if(record.dueAt >= record.issuedAt){
return next(buildUsageError('E_INVALID_NEW_RECORD', 'issuedAt date must be equal or greater than dueAt date', 'invoice'))
}
next();
}
};
beforeCreate method in model as first param takes values. The best place for this kind of validation I see here.
beforeCreate: (values, next){
if (values.dueAt >= values.issuedAt) {
return next({error: ['...']})
}
next()
}
I'm using MongoDB as a log keeper for my app to then sync mobile clients. I have this models set up in NodeJS:
var UserArticle = new Schema({
date: { type: Number, default: Math.round((new Date()).getTime() / 1000) }, //Timestamp!
user: [{type: Schema.ObjectId, ref: "User"}],
article: [{type: Schema.ObjectId, ref: "Article"}],
place: Number,
read: Number,
starred: Number,
source: String
});
mongoose.model("UserArticle",UserArticle);
var Log = new Schema({
user: [{type: Schema.ObjectId, ref: "User"}],
action: Number, // O => Insert, 1 => Update, 2 => Delete
uarticle: [{type: Schema.ObjectId, ref: "UserArticle"}],
timestamp: { type: Number, default: Math.round((new Date()).getTime() / 1000) }
});
mongoose.model("Log",Log);
When I want to retrive the log I use the follwing code:
var log = mongoose.model('Log');
log
.where("user", req.session.user)
.desc("timestamp")
.populate("uarticle")
.populate("uarticle.article")
.run(function (err, articles) {
if (err) {
console.log(err);
res.send(500);
return;
}
res.json(articles);
As you can see, I want mongoose to populate the "uarticle" field from the Log collection and, then, I want to populate the "article" field of the UserArticle ("uarticle").
But, using this code, Mongoose only populates "uarticle" using the UserArticle Model, but not the article field inside of uarticle.
Is it possible to accomplish it using Mongoose and populate() or I should do something else?
Thank you,
From what I've checked in the documentation and from what I hear from you, this cannot be achieved, but you can populate the "uarticle.article" documents yourself in the callback function.
However I want to point out another aspect which I consider more important. You have documents in collection A which reference collection B, and in collection B's documents you have another reference to documents in collection C.
You are either doing this wrong (I'm referring to the database structure), or you should be using a relational database such as MySQL here. MongoDB's power relies in the fact you can embed more information in documents, thus having to make lesser queries (having your data in a single collection). While referencing something is ok, having a reference and then another reference doesn't seem like you're taking the full advantage of MongoDB here.
Perhaps you would like to share your situation and the database structure so we could help you out more.
You can use the mongoose-deep-populate plugin to do this. Usage:
User.find({}, function (err, users) {
User.deepPopulate(users, 'uarticle.article', function (err, users) {
// now each user document includes uarticle and each uarticle includes article
})
})
Disclaimer: I'm the author of the plugin.
I faced the same problem,but after hours of efforts i find the solution.It can be without using any external plugin:)
applicantListToExport: function (query, callback) {
this
.find(query).select({'advtId': 0})
.populate({
path: 'influId',
model: 'influencer',
select: { '_id': 1,'user':1},
populate: {
path: 'userid',
model: 'User'
}
})
.populate('campaignId',{'campaignTitle':1})
.exec(callback);
}
Mongoose v5.5.5 seems to allow populate on a populated document.
You can even provide an array of multiple fields to populate on the populated document
var batch = await mstsBatchModel.findOne({_id: req.body.batchId})
.populate({path: 'loggedInUser', select: 'fname lname', model: 'userModel'})
.populate({path: 'invoiceIdArray', model: 'invoiceModel',
populate: [
{path: 'updatedBy', select: 'fname lname', model: 'userModel'},
{path: 'createdBy', select: 'fname lname', model: 'userModel'},
{path: 'aircraftId', select: 'tailNum', model: 'aircraftModel'}
]});
how about something like:
populate_deep = function(type, instance, complete, seen)
{
if (!seen)
seen = {};
if (seen[instance._id])
{
complete();
return;
}
seen[instance._id] = true;
// use meta util to get all "references" from the schema
var refs = meta.get_references(meta.schema(type));
if (!refs)
{
complete();
return;
}
var opts = [];
for (var i=0; i<refs.length; i++)
opts.push({path: refs[i].name, model: refs[i].ref});
mongoose.model(type).populate(instance, opts, function(err,o){
utils.forEach(refs, function (ref, next) {
if (ref.is_array)
utils.forEach(o[ref.name], function (v, lnext) {
populate_deep(ref.ref_type, v, lnext, seen);
}, next);
else
populate_deep(ref.ref_type, o[ref.name], next, seen);
}, complete);
});
}
meta utils is rough... want the src?
or you can simply pass an obj to the populate as:
const myFilterObj = {};
const populateObj = {
path: "parentFileds",
populate: {
path: "childFileds",
select: "childFiledsToSelect"
},
select: "parentFiledsToSelect"
};
Model.find(myFilterObj)
.populate(populateObj).exec((err, data) => console.log(data) );