I'm not sure what's wrong but following the documentation on how to grab additional fields from the server here:
return Meteor.users.find({_id: this.userId}, {fields: {'other': 1, 'things': 1}});
What ends up happening is that it only publishes the two fields other and things instead of the default fields of emails, profile, username and other, things.
This is what I have return Meteor.users.find({username: username}, {fields: {'status': 1});
So what ends up happening is that the client is only receiving two fields _id, and status. I don't want to manually add all the 'default' fields to each and every publish function, what am I doing wrong?
If you want to apply DRY principle then simply create defaultInclusionFields:
var defaultInclusionFields = function() {
return {
emails:1,
profile:1,
username:1
};
}
and extend defaultInclusionFields() using underscore with your custom fields ('other', 'status', ... ):
Meteor.users.find(
{username: username},
{fields: _.extend(defaultInclusionFields(),{"other":1,"status":1})
);
Note that you can not mix inclusions and exclusions.
Related
I have a basic schema that implements getters/setters:
var User = new Schema( {
username : { type : String , required : true , get: getUsername, set: setUsername }
} );
User.set('toObject', { getters: true , virtuals : true } );
User.set('toJSON', { getters: true , virtuals : true } );
UserModel = mongoose.model('User', User);
setUsername is fairly simple but "randomizes" the username, and obviously getUsername retrieves the original value. Now, everytime I call setUsername, I will get a different "random" string (I mean it's pretty much a hash function).
My question is, can I somehow use the getter in a query?
Like
UserModel.$where( 'this.username.get() == "<somestring>"' ).exec( function( err , users ) {
// do something with the users
}
} ); // here I get MongoError: TypeError: this.username.get is not a function
or
UserModel.find( { $where: function() {
return( getUsername( this.username ) == "<somestring>" )
} } , function( err , users ) {
// do something with the users
} ); // here I get MongoError: ReferenceError: getUsername is not defined
I tried adding a getUsername method to the schema as well, adding virtuals, etc., but I cannot seem to find a solution. i've tried about 15 different syntaxes but I either get an error, an empty array or all users.
Basically if I have a user whose username is "a", it'll be saved in my DB as *"b", "c", "d", or whatever else the setUsername function sets it to.
I'd like to retrieve the user knowing only that their username is "a".
Thank you!
Yes, this should theoretically be possible using query middleware, but you might have to think a little differently:
Let's say you want to run a query like this:
UserModel.find({user: 'a'})
where 'a' is the unscrambled input and you actually want to automatically lookup {user: getUser('a')}, which we'll say is {user: 'b'}
Then you could use this middleware to modify your Query like this:
const userFilter = function (next) {
const query = this.getQuery();
if (query.userName) {
// this transforms the query in-place from {user: 'a'} to {user : 'b'}
query.userName = setUserName(query.userName)};
}
return next();
};
// let's hook this one in!
User.pre('find', userFilter);
Note: This will hook on all queries including ".userName" If you only use UserModel.find() then this will suffice, but otherwise you might also want to register this hook on ['count', 'find', 'findOne', 'findOneAndRemove','findOneAndUpdate', 'remove', 'update', 'updateOne', 'updateMany'] and that some queries (iirc e.g. findByIdAndUpdate) is supposed to bypass mongoose and directly use the mongodbDriver, which might also bypass this hook... Even though it still seems to work currently, so you might want to test all kinds of functions with it)
EDIT:
Looking back at your question, I am not sure, if I understood your question correctly. What does the setUsername function actually return? Is it always the same output for the same input? If so, you basically always to query {userName: setUserName('a')}, right?
In Mongoose, I can use a query populate to populate additional fields after a query. I can also populate multiple paths, such as
Person.find({})
.populate('books movie', 'title pages director')
.exec()
However, this would generate a lookup on book gathering the fields for title, pages and director - and also a lookup on movie gathering the fields for title, pages and director as well. What I want is to get title and pages from books only, and director from movie. I could do something like this:
Person.find({})
.populate('books', 'title pages')
.populate('movie', 'director')
.exec()
which gives me the expected result and queries.
But is there any way to have the behavior of the second snippet using a similar "single line" syntax like the first snippet? The reason for that, is that I want to programmatically determine the arguments for the populate function and feed it in. I cannot do that for multiple populate calls.
After looking into the sourcecode of mongoose, I solved this with:
var populateQuery = [{path:'books', select:'title pages'}, {path:'movie', select:'director'}];
Person.find({})
.populate(populateQuery)
.execPopulate()
you can also do something like below:
{path:'user',select:['key1','key2']}
You achieve that by simply passing object or array of objects to populate() method.
const query = [
{
path:'books',
select:'title pages'
},
{
path:'movie',
select:'director'
}
];
const result = await Person.find().populate(query).lean();
Consider that lean() method is optional, it just returns raw json rather than mongoose object and makes code execution a little bit faster! Don't forget to make your function (callback) async!
This is how it's done based on the Mongoose JS documentation http://mongoosejs.com/docs/populate.html
Let's say you have a BookCollection schema which contains users and books
In order to perform a query and get all the BookCollections with its related users and books you would do this
models.BookCollection
.find({})
.populate('user')
.populate('books')
.lean()
.exec(function (err, bookcollection) {
if (err) return console.error(err);
try {
mongoose.connection.close();
res.render('viewbookcollection', { content: bookcollection});
} catch (e) {
console.log("errror getting bookcollection"+e);
}
//Your Schema must include path
let createdData =Person.create(dataYouWant)
await createdData.populate([{path:'books', select:'title pages'},{path:'movie', select:'director'}])
I'm using the request library to make calls from one sails app to another one which exposes the default blueprint endpoints. It works fine when I query by non-id fields, but I need to run some queries by passing id arrays. The problem is that the moment you provide an id, only the first id is considered, effectively not allowing this kind of query.
Is there a way to get around this? I could switch over to another attribute if all else fails but I need to know if there is a proper way around this.
Here's how I'm querying:
var idArr = [];//array of ids
var queryParams = { id: idArr };
var options: {
//headers, method and url here
json: queryParams
};
request(options, function(err, response, body){
if (err) return next(err);
return next(null, body);
});
Thanks in advance.
Sails blueprint APIs allow you to use the same waterline query langauge that you would otherwise use in code.
You can directly pass the array of id's in the get call to receive the objects as follows
GET /city?where={"id":[1, 2]}
Refer here for more.
Have fun!
Alright, I switched to a hacky solution to get moving.
For all models that needed querying by id arrays, I added a secondary attribute to the model. Let's call it code. Then, in afterCreate(), I updated code and set it equal to the id. This incurs an additional database call, but it's fine since it's called just once - when the object is created.
Here's the code.
module.exports = {
attributes: {
code: {
type: 'string'//the secondary attribute
},
// other attributes
},
afterCreate: function (newObj, next) {
Model.update({ id: newObj.id }, { code: newObj.id }, next);
}
}
Note that newObj isn't a Model object as even I was led to believe. So we cannot simply update its code and call newObj.save().
After this, in the queries having id arrays, substituting id with code makes them work as expected!
// in server.js
Meteor.publish("directory", function () {
return Meteor.users.find({}, {fields: {emails: 1, profile: 1}});
});
// in client.js
Meteor.subscribe("directory");
I want to now get the directory listings queried from the client like directory.findOne() from the browser's console. //Testing purposes
Doing directory=Meteor.subscribe('directory')/directory=Meteor.Collection('directory') and performing directory.findOne() doesn't work but when I do directory=new Meteor.Collection('directory') it works and returns undefined and I bet it CREATES a mongo collection on the server which I don't like because USER collection already exists and it points to a new Collection rather than the USER collection.
NOTE: I don't wanna mess with how Meteor.users collection handles its function... I just want to retrieve some specific data from it using a different handle that will only return the specified fields and not to override its default function...
Ex:
Meteor.users.findOne() // will return the currentLoggedIn users data
directory.findOne() // will return different fields taken from Meteor.users collection.
If you want this setup to work, you need to do the following:
Meteor.publish('thisNameDoesNotMatter', function () {
var self = this;
var handle = Meteor.users.find({}, {
fields: {emails: 1, profile: 1}
}).observeChanges({
added: function (id, fields) {
self.added('thisNameMatters', id, fields);
},
changed: function (id, fields) {
self.changed('thisNameMatters', id, fields);
},
removed: function (id) {
self.removed('thisNameMatters', id);
}
});
self.ready();
self.onStop(function () {
handle.stop();
});
});
No on the client side you need to define a client-side-only collection:
directories = new Meteor.Collection('thisNameMatters');
and subscribe to the corresponding data set:
Meteor.subscribe('thisNameDoesNotMatter');
This should work now. Let me know if you think this explanation is not clear enough.
EDIT
Here, the self.added/changed/removed methods act more or less as an event dispatcher. Briefly speaking they give instructions to every client who called
Meteor.subscribe('thisNameDoesNotMatter');
about the updates that should be applied on the client's collection named thisNameMatters assuming that this collection exists. The name - passed as the first parameter - can be chosen almost arbitrarily, but if there's no corresponding collection on the client side all the updates will be ignored. Note that this collection can be client-side-only, so it does not necessarily have to correspond to a "real" collection in your database.
Returning a cursor from your publish method it's only a shortcut for the above code, with the only difference that the name of an actual collection is used instead of our theNameMatters. This mechanism actually allows you to create as many "mirrors" of your datasets as you wish. In some situations this might be quite useful. The only problem is that these "collections" will be read-only (which totally make sense BTW) because if they're not defined on the server the corresponding `insert/update/remove' methods do not exist.
The collection is called Meteor.users and there is no need to declare a new one on neither the server nor the client.
Your publish/subscribe code is correct:
// in server.js
Meteor.publish("directory", function () {
return Meteor.users.find({}, {fields: {emails: 1, profile: 1}});
});
// in client.js
Meteor.subscribe("directory");
To access documents in the users collection that have been published by the server you need to do something like this:
var usersArray = Meteor.users.find().fetch();
or
var oneUser = Meteor.users.findOne();
Getting into sails.js - enjoying the cleanliness of models, routes, and the recent addition of associations. My dilemma:
I have Users, and Groups. There is a many-many relationship between the two.
var User = {
attributes: {
username: 'string',
groups: {
collection: 'group',
via: 'users'
}
}
};
module.exports = User;
...
var Group = {
attributes: {
name: 'string',
users: {
collection: 'user',
via: 'groups',
dominant: true
}
}
};
module.exports = Group;
I'm having difficulty understanding how I would save a user and it's associated groups.
Can I access the 'join table' directly?
From an ajax call, how should I be sending in the list of group ids to my controller?
If via REST URL, is this already accounted for in blueprint functions via update?
If so - what does the URL look like? /user/update/1?groups=1,2,3 ?
Is all of this just not supported yet? Any insight is helpful, thanks.
Documentation for these blueprints is forthcoming, but to link two records that have a many-to-many association, you can use the following REST url:
POST /user/[userId]/groups
where the body of the post is:
{id: [groupId]}
assuming that id is the primary key of the Group model. Starting with v0.10-rc5, you can also simultaneously create and a add a new group to a user by sending data about the new group in the POST body, without an id:
{name: 'myGroup'}
You can currently only add one linked entity at a time.
To add an entity programmatically, use the add method:
User.findOne(123).exec(function(err, user) {
if (err) {return res.serverError(err);}
// Add group with ID 1 to user with ID 123
user.groups.add(1);
// Add brand new group to user with ID 123
user.groups.add({name: 'myGroup'});
// Save the user, committing the additions
user.save(function(err, user) {
if (err) {return res.serverError(err);}
return res.json(user);
});
});
Just to answer your question about accessing the join tables directly,
Yes you can do that if you are using Model.query function. You need to check the namees of the join tables from DB itself. Not sure if it is recommended or not but I have found myself in such situations sometimes when it was unavoidable.
There have been times when the logic I was trying to implement involved a lot many queries and it was required to be executed as an atomic transaction.
In those case, I encapsulated all the DB logic in a stored function and executed that using Model.query
var myQuery = "select some_db_function(" + <param> + ")";
Model.query(myQuery, function(err, result){
if(err) return res.json(err);
else{
result = result.rows[0].some_db_function;
return res.json(result);
}
});
postgres has been a great help here due to json datatype which allowed me to pass params as JSON and also return values as JSON