I have a collection users like this:
[{
'uid' : '1',
'favourites' : [
{ // fav1 },
{ // fav2 },
{ // fav3 },
etc
]
},
{
'uid' : '2',
'favourites' : [
{ // fav1 },
{ // fav2 },
{ // fav3 },
etc
]
},
etc
]
In some situations I have to update the favourites collection with a new "fav" and I can do that in this way:
final doc = FirebaseFirestore.instance.collection('users').doc(userId);
doc.update({ 'favourites': FieldValue.arrayUnion([fav.toJson()]) });
however the item might be not there so I have to use doc.set to create a new item. As I am new with Firebase, what is a "best practice" for a problem like this (if the element is not there create it first, otherwise update it)?
You can specify a merge option to set, which does precisely what you want:
doc.set({ 'favourites': FieldValue.arrayUnion([fav.toJson()]) }, SetOptions(merge : true))
You can use a function that can check if there is a doc or not with that specific info. And you can create a if-else statement depends on if there is a doc named like that or not.
An example function for checking the doc:
Future<bool> checkIfDocExists(String stuffID) async {
try {
/// Check If Document Exists
// Get reference to Firestore collection
var collectionRef = FirebaseFirestore.instance
.collection('favorites');
var doc = await collectionRef.doc(userId).get();
return doc.exists;
} catch (e) {
throw e;
}
}
Related
I'm struggling with a recursive loop and nested create/select statements. I'm receiving an object from a post request with the following structure:
11.6042
---11.6042_01
---11.6042_02
---11.6042_02
---14x10-100
------14x10-100_01
---14x10-100
------14x10-100_01
---14x10-100
------14x10-100_01
---M10-DIN929_14020
---M10-DIN929_14020
---11.6042_05
Wanted behaviour: travel through the structure recursive, add record to Part table, self join with parent part, join with PartLib table, if no match present create PartLib record and match created record. Process next part.
The problem: part 14x10-100 occurs three times in the structure. I want to create a record for part 14x10-100 in the part_lib table and refer to that record three times. What actually happens is that for each 14x10-100 part a corresponding record in the part_lib table is created in stead of one create and two matches. If I run it again it will match like excpected. I suspect I'm lost in the promise/async await parts of the code.
Below the relevant code. I've removed some attribute mappings for readability. My thoughts behind it: I'm not returning new promises like normal in a async function since Sequelize already returns a promise. When creating a part I'm awaiting (or at least I think so) the partLibController calls to ensure that all matching/creating/joining is done before proceeding to the next part in the structure.
Thanks a bunch!!
Recursive loop
function parseChild(child, modelId, parentId, userId, level) {
return new Promise((resolve, reject) => {
partController.create({
parent_id: parentId
, name: child.name
}, { id: userId }).then((part) => {
resolve({ child: child, level: level });
if (child.children) {
child.children.forEach(grandChild => {
parseChild(grandChild, modelId, part.part_id, userId, level + '---');
});
}
}).catch(error => { console.log(error); });
}).then((obj) => { console.log(`${obj.level} ${obj.child.name}`); });
}
PartController Create
async function create(partBody, currentUser) {
let { parent_id, name } = partBody;
const match = await partLibController.match(name);
let partLibId = null;
if (match.length == 0) {
const partLib = await partLibController.createFromPart(partBody, currentUser);
partLibId = partLib.part_lib_id;
} else {
partLibId = match[0].dataValues.part_lib_id
}
return ModelAssembly.create({
parent_id: parent_id
, name: name
, part_lib_id: partLibId
});
}
PartLibController Match
function match(name) {
return PartLib.findAll({
where: {
name: name
},
});
}
PartLibController CreateFromPart
function createFromPart(partBody, currentUser) {
let { name } = partBody;
return PartLib.create({
name,
});
}
Thanks to AKX I've solved the problem: hero
The problem was in the recursive call itself I suppose but here's the working code:
async function parseChild(child, modelId, parentId, userId, level) {
const body = {
parent_id: parentId
, name: child.name
};
const ma = await partController.create(body, { id: userId });
if (child.children) {
for (const grandChild of child.children) {
await parseChild(grandChild, modelId, ma.part_id, userId, level + '---');
}
}
return;
}
I just want to Publish the relational Data for a Publication to client, but the issue is my Relational Data field is array of ID's of a Different Collection, I tried Different Packages but all works with single Relational ID but not working with Array of relational ID's, let assume I have two Collection Companies and Meteor.users below is my Company Document Looks like
{
_id : "dYo4tqpZms9j8aG4C"
owner : "yjzakAgYWejmJcuHz"
name : "Labbaik Waters"
peoples : ["yjzakAgYWejmJcuHz", "yjzakAgYWejmJcuHz"],
createdAt: "2019-09-18T15:33:29.952+00:00"
}
here you can see peoples field contains the user ID's as Array, so How I publish this userId's as user Documents, as for example I tried the most popular meteor package named publishComposit, when I tried Loop in Children's find, I got undefined in children i.e below
publishComposite('compoundCompanies', {
find() {
// Find top ten highest scoring posts
return Companies.find({
owner: this.userId
}, {sort: {}});
},
children: [
{
find(company) {
let cursors = company.peoples.forEach(peopleId => {
console.log(peopleId)
return Meteor.users.find(
{ _id: peopleId },
{ fields: { profile: 1 } });
})
//here cursor undefined
console.log(cursors)
return cursors
}
}
]
});
and if I implement async loop in children's find I got error like below code
publishComposite('compoundCompanies', {
find() {
// Find top ten highest scoring posts
return Companies.find({
owner: this.userId
}, {sort: {}});
},
children: [
{
async find(company) {
let cursors = await company.peoples.forEach(peopleId => {
console.log(peopleId)
return Meteor.users.find(
{ _id: peopleId },
{ fields: { profile: 1 } });
})
//here cursor undefined
console.log(cursors)
return cursors
}
}
]
});
the error occured in above code is Exception in callback of async function: TypeError: this.cursor._getCollectionName is not a function
I don't know what I am exactly doing wrong here, or implementing package function not as intended any help will be greatly appropriated
EDIT: my desired result should be full user documents instead of ID no matter it mapped in same peoples array or as another fields I just want as below
{
_id: "dYo4tqpZms9j8aG4C",
owner: "yjzakAgYWejmJcuHz",
name: "Labbaik Waters",
peoples: [
{
profile: {firstName: "Abdul", lastName: "Hameed"},
_id: "yjzakAgYWejmJcuHz"
}
],
createdAt: "2019-09-18T15:33:29.952+00:00"
}
I ran into a similar problem couple of days ago. There are two problems with the provided code. First, using async; it's not needed and rather complicates things. Second, publishComposite relies on receiving one cursor not multiple within its children to work properly.
Below is a snippet of the code used to solve the problem I had, hopefully you can replicate it.
Meteor.publishComposite("table.conversations", function(table, ids, fields) {
if (!this.userId) {
return this.ready();
}
check(table, String);
check(ids, Array);
check(fields, Match.Optional(Object));
return {
find() {
return Conversation.find(
{
_id: {
$in: ids
}
},
{ fields }
);
},
children: [
{
find(conversation) {
// constructing one big cursor that entails all of the documents in one single go
// as publish composite cannot work with multiple cursors at once
return User.find(
{ _id: { $in: conversation.participants } },
{ fields: { profile: 1, roles: 1, emails: 1 } }
);
}
}
]
};
});
I want to update a collection called SMUProfiles, through a method called classroom.delete. I want to pull out the classroom_id from 2 places inside SMUProfiles i.e. one inside classrooms.owner which has an array of codes, and the other inside array classrooms.students.
I have successfully one the $set part, and now trying to add the $pull, but $pull doesn't seem to work.
Can we do the $set and $pull in such way?
/* Method for deleting Classroom */
'classroom.delete'(classroom_id) {
if (!this.userId) {
throw new Meteor.Error('not-authorised');
}
Classrooms.remove(classroom_id)
let classids = Classrooms.find({ owner: this.userId }).fetch().map(function(classrooms){
return classrooms._id })
//console.log(classids);
SMUProfiles.update({
owner: this.userId,
}, {
$set: {
'classrooms.owner': classids
},
$pull: {
'classrooms.students': classroom_id
}
}
)
}
You're trying to $set and $pull on the same field in the same update - the two operations conflict; so no, you can't use these operators in this way.
You could easily split this into two:
SMUProfiles.update(
{ owner: this.userId },
{ $set: { 'classrooms.owner': classids },
);
SMUProfiles.update(
{ owner: this.userId },
{ $pull: { 'classrooms.students': classroom_id },
);
See e.g. this answer
I have data like this:
scores: {
uid1: {
score: 15,
displayName: "Uciska"
},
uid2: {
score: 3,
displayName: "Bob"
},
uid3: {
etc...
}
}
I want to rank them by score and keep only the top 100.
I did that by following the doc. But it does not work. It always returns the same order even if the score changes.
const query = firebase.database().ref('scores')
.orderByChild('score')
.limitToLast(100)
query.on('child_added', snapshot => {
const score = snapshot.val().score
console.log(score)
})
I added that too in the rules to optimize but I'm not sure it's correct:
"scores": {
".indexOn": ["score"]
}
What is the right way to go?
Your code is correct and should show the desired result.
You may encounter difficulties to see the result due to the 'child_added' event since "the listener is passed a snapshot containing the new child's data", as detailed here in the doc.
You could use the once() method, as follows, which will show the result a bit more clearly since it will display the entire set of scores.
const query = firebase.database().ref('scores')
.orderByChild('score')
.limitToLast(100)
query.once('value', function (snapshot) {
snapshot.forEach(function (childSnapshot) {
var childKey = childSnapshot.key;
var childData = childSnapshot.val();
console.log(childData);
// ...
});
});
Also, your rule can be written as ".indexOn": "score" since there is only one parameter.
Forms of this question have been asked a few times, but I've been unable to find a solution:
I have a schema like this (simplified):
StatusObject = new SimpleSchema({
statusArray: [statusSchema]
});
where statusSchema is
{
topicId:{
type: String,
optional: true
},
someInfo:{
type: Number,
optional: true,
decimal: true
},
otherInfo:{
type: Number,
optional: true
}
}
I am trying to upsert - with the following meteor method code:
var upsertResult = BasicInfo.update({
userId: this.userId,
statusArray: {
$elemMatch: { topicId : newStatus.topicId }
}
}, {
$set: {
"statusArray.$.topicId": newStatus.topicId,
"statusArray.$.someInfo": newStatus.someInfo,
"statusArray.$.otherInfo": newStatus.otherInfo
}
}, {
multi: true,
upsert: true
});
But I keep getting an error: statusArray must be an array
I thought by adding the $, I was making sure it is recognized as an array? What am I missing?
It seems (after your clarification comments), that you want to find a document with particular userId and modify its statusArray array using one of these scenarios:
Update existing object with particular topicId value;
Add a new object if the array doens't have one with particular topicId value.
Unfortunately, you can't make it work using just one DB query, so it should be like this:
// try to update record
const updateResult = BasicInfo.update({
userId: this.userId,
'statusArray.topicId': newStatus.topicId
}, {
$set: {
"statusArray.$": newStatus
}
});
if (!updateResult) {
// insert new record to array or create new document
BasicInfo.update({
userId: this.userId
}, {
$push: {
statusArray: newStatus
},
$setOnInsert: {
// other needed fields
}
}, {
upsert: true
});
}
Your code is treating StatusArray as an object,
Before you do the upsert, build the status array first, assuming that your current value is currentRecord
newStatusArray = currentRecord.statusArray
newStatusArray.push({
topicId: newStatus.topicId,
someInfo : newStatus.someInfo,
otherInfo: newStatus.otherInfo
})
and in the upsert, simply refer to it like this
$set: { statusArray: newStatusArray}