I have a question regarding Firestore,
I created a "category" collection in which I have several documents, I created a "construction sites" sub-collection!
I want to retrieve all my sub collections from each category, but when I try to do like this:
useEffect(() => {
const listConstruction = [];
db.collection('category').get().then((collectionCategory) => {
collectionCategory.forEach((doc) => {
doc.ref.collection('construction').get().then((collectionConstruction) => {
collectionConstruction.forEach((doc1) => {
listConstruction.push({
idCategory: doc.id,
libelleCategory: doc.data().libelle,
title: doc1.data().title,
description: doc1.data().description,
});
});
});
});
}).finally(() => {
setConstruction(listConstruction);
});
}, []);
The problem is that it hasn't finished pushing the constructs it passes into my finally!
Having no experience with NoSQL and Firestore yet, I would have liked if I'm not completely wrong about its use and if so how to fix it?
If I correctly understand your problem, you need to use a Collection Group query.
As explained in the doc:
A collection group consists of all collections with the same ID. By default, queries retrieve results from a single collection in your
database. Use a collection group query to retrieve documents from a
collection group instead of from a single collection.
Side note: If you want to call asynchronous methods in a forEach loop, you should use Promise.all().
Related
I'm executing this mutation in my NewBook component:
const [addBook] = useMutation(ADD_BOOK, {
update: (cache, response) => {
cache.updateQuery({ query: ALL_BOOKS }, ({ allBooks }) => {
return { allBooks: allBooks.concat(response.data.addBook) };
});
},
refetchQueries: [{ query: ALL_AUTHORS }, { query: ALL_GENRES }],
options: {
awaitRefetchQueries: true,}});
Instead of having to refetch those two queries, I'd like to update them like ALL_BOOKS - but could not find any example in the docs. Does anyone know a way to accomplish that?
Thank you.
What you need to do is make multiple cache updates based on response data.
Once you add your new book to the query, the next step is to fetch all authors.
cache.updateQuery({ query: ALL_BOOKS }, ({ allBooks }) => {
return { allBooks: allBooks.concat(response.data.addBook) };
});
//Get all authors
const existingAuthors = cache.readQuery({
query: ALL_AUTHORS,
//variables: {}
});
//If we never called authors, do nothing, as the next fetch will fetch updated authors. This might be a problem in the future is some cases, depending on how you fetch data. If it is a problem, just rework this to add newAuthor to the array, like allAuthors: [newAuthor]
if(!existingAuthors.?length) {
return null
}
The next thing is that we need to compare the new book's author with existing authors to see if a new author was added.
//continued
const hasAuthor = existingAuthors.find(author => author.id === response.data.createBook.id)
//Double check response.data.createBook.id. I don't know what is returned from response
//If author already exists, do nothing
if(hasAuthor) {
return null
}
//Get a new author. Make sure that this is the same as the one you fetch with ALL_AUTHORS.
const newAuthor = {
...response.data.createBook.author //Check this
}
cache.writeQuery({
query: ALL_AUTHORS,
//variables: {}
data: {
allAuthors: [newAuthor, ...existingAuthors.allAuthors]
},
});
Then continue the same with ALL_GENRES
Note:
If you called ALL_GENERES or ALL_BOOKS with variables, you MUST put the SAME variables in the write query and read query. Otherwise Apollo wont know what to update
Double check if you are comparing numbers or strings for authors and genres
Double check all of the variables I added, they might be named different at your end.
Use console.log to check incoming variables
You can probably make this in less lines. There are multiple ways to update cache
If it doesn't work, console.log cache after the update and see what exactly did apollo do with the update (It could be missing data, or wrong variables.)
Add more checks to ensure some cases like: response.data returned null, authors already fetched but there are none, etc...
I'm trying to figure out how to access a full object reference through Sanity.io. Example code:
const fetchExperience = async () => {
const data = await sanityClient.fetch(`*[_type == 'experience'] {
company,
title,
'techStack': stack[]->technology,
'imageUrl': image.asset->url,
}`);
return data;
};
I have another schema declared called Skill that contains two fields: technology, and icon. This Experience schema that I am working with above and references the Skill schema. Using this post, I was able to figure out how to grab a singular field through the reference and populate a field called techStack. However, I want to take this one step further: how can I write a GROQ that returns me an array of objects that might look like this?:
[
{ technology: 'React.js', icon: 'pretend-this-is-a-link-to-an-asset' },
...
]
Thanks in advance!
You can do this to get the specific fields:
"techStack": stack[]-> { technology, icon }
I am performing a query on my collection documents and trying to return just all phone numbers into an array. I just want to set the phone numbers into array for use by another function. Firebase docs only show a console log for (doc.id) and (doc.data) and no practical use for any other objects in your documents. My console log for info.phoneNumbers returns all the phoneNumbers.
async getPhone() {
await this.afs.collection('members', ref => ref.where('phoneNumber', '>=', 0))
.get().toPromise()
.then(snapshot => {
if (snapshot.empty) {
console.log('No Matches');
return;
}
this.getInfo(snapshot.docs);
});
}
getInfo(data) {
data.forEach(doc => {
let info = doc.data();
console.log(info.phoneNumber, 'Phonenumbers');
// let myArray = [];
// myArray.push(doc.doc.data());
// const phoneNumber = info.phoneNumber as [];
// console.log(myArray, 'ARRAY');
return info.phoneNumber;
})
}```
Firestore is a "document store database". You fetch and store entire DOCUMENTS (think "JSON objects") at a time. One of the "anti-patterns" when using document store databases is thinking of them in SQL/relational DB terms. In SQL/relational DB, you "normalize" data. But in a document store database (a "NoSQL" database) we explicitly denormalize data -- that is, we duplicate data -- across documents on write operations. This way, when you fetch a document, it has all the data you need for its use cases. You typically want to avoid "JOINs" and limit the number of references/keys in your data model.
What you are showing in the code above is valid in terms of fetching documents, and extracting the phoneNumber field from each. However, use of .forEach() is likely not what you want. forEach() iterates over the given array and runs a function, but the return value of forEach() is undefined. So the return info.phoneNumber in your code is not actually doing anything.
You might instead use .map() where the return value of the map() function is a new array, containing one entry for each entry of the original array, and the value of that new array is the return value from map()'s callback parameter.
Also, mixing await and .then()/.catch() is usually not a good idea. It typically leads to unexpected outcomes. I try to use await and try/catch, and avoid .then()/.catch() as much as possible.
So I would go with something like:
try {
let querySnap = await this.afs.collection('members', ref =>
ref.where('phoneNumber', '>=', 0)).get();
let phoneNumbers = await this.getInfo(querySnap.docs[i].data());
} catch(ex) {
console.error(`EXCEPTION: ${ex.message}`);
}
getInfo(querySnapDocs) {
let arrayPhoneNumbers = querySnapDocs.map(docSnap => {
let info = doc.data();
let thePhoneNum = info.phoneNumber
console.log(`thePhoneNum is: ${thePhoneNum}`);
return thePhoneNum;
});
return arrayPhoneNumbers;
});
I solved this with help and I hope this may be helpful to others in Getting access to 1 particular field in your documents. In my service:
async getPhone() {
return await this.afs.collection('members', ref => ref.where('phoneNumber', '>=', 0))
.get().toPromise()
.then(snapshot => {
if (snapshot.empty) {
console.log('No Matches');
return;
}
return this.getInfoNum(snapshot.docs);
});
}
getInfoNum(data) {
return data.map(doc => {
let info = doc.data();
return info.phoneNumber
});
}
In my Component using typescript
phoneNumbers: string[] = [];
getPhone() {
this.dbService.getPhone().then(phoneNumbers => {
this.phoneNumbers = phoneNumbers;
this.smsGroupForm.controls.number.setValue(phoneNumbers.join(',')) //sets array seperated by commas
console.log(phoneNumbers);
});
}
This returns all the phone numbers in a comma separated array.
In my template I pull the numbers into an input for another function to send multiple text. Code in the template is not polished yet for the form, I am just getting it there for now.
<ion-list>
<ion-item *ngFor="let phoneNumber of phoneNumbers">
<ion-label position="floating">Phone Number</ion-label>
<ion-input inputmode="number"
placeholder="Phone Number"
formControlName="number"
type="number">{{ phoneNumber }}
</ion-input>
</ion-item>
</ion-list>
I have a firestore with lessons, see the picture below, I get from the firestore the title property from each object and display it in the browser, but everytime I refresh the website the lessons are sorted by how they want, why is that happening? I want to sort them how I want, I want to start with 'Introduction' and so on, how can I do that? I think the orderBy() is not working here.
As you see in the image above, the order in the firestore is alphabetical, but in my page is sorted by its own, see the picture below.
I want the result to be by in a specific order, for example we have the following titles, these titles are from the firestore: "Display", "Introduction", "Alignment", my problem is that these 3 titles are in a new order every time I refresh the website, I want them to be: "Introduction", "Alignment", "Display". In my case I have more titles but this is what's happening, I don't know how to align them how I want or even alphabetical if is possible.
Below is the code that I used to get the data from firestore:
useEffect(() => {
db.collection("users")
.doc(`${user.uid}`)
.get()
.then((doc) => {
const allData = { ...doc.data(), id: doc.id };
const intoArray = Object.entries(allData);
intoArray.sort(); // I used sort here because I had the same problem
// (every time a new order) with the
// data when I converted it to an array
const getCSSLessons = intoArray[0][1];
const cssData = Object.values(getCSSLessons);
setCss(cssData);
const getHTMLLessons = intoArray[1][1];
const htmlData = Object.values(getHTMLLessons);
setHtml(htmlData);
const getResLessons = intoArray[3][1];
const resData = Object.values(getResLessons);
setRes(resData);
})
.catch((error) => console.log(error));
}, [user]);
I tried using sort(), for a variable (htmlData) but its not working.
Also, I use map() to display them, if this helps you to answer to my question.
If you use sort without any argument, it will sort array elements alphabetically. It looks like your array elements are arrays, which will end with unexpected behaviors. Use sort argument to ensure it uses your own sorting rules. For example:
const intoArray = Object
.entries(allData)
// I don't know what should be the sorting algorithm
// As an example, I consider each element (`a` and `b`) to
// be arrays and compare both first element as a Number
.sort( (a, b) => a[0] - b[0])
Edit
A more secure way to find elements in an array is to use find:
const getCSSLessons = intoArray[0]
.find( element => element.name === 'CSS Lessons');
I was doing something unnecessary as you see in the first picture I had a main object css and in that object I had sub-objects like alignment and in the sub object I had the properties that I want to display, that sub object was unncessary, istead of sub objects with a pre defined name, I let the firebase to count the sub objects and add as a name a number and the order is the same as I wanted to be.
The code that I used to add data to firebase:
fire
.auth()
.createUserWithEmailAndPassword(email, password)
.then((cred) => {
return db
.collection("users")
.doc(cred.user.uid)
.set({
css: [
{
title: "Introduction",
path: "/css3/introduction",
},
{
title: "Priority",
path: "/css3/priority",
},
],
});
I've got two types of docs in pouchdb:
todos - list of todos
user - just user number put in pochdb by separate form
When I write todos I also have variable for userNo. This way I know which todos he owns.
I've got two functions in provider to get todos, and user number.
In html list I want to filter todos by user number through pipe:
<ion-item-sliding *ngFor="let todo of todos | filter : 'numer_p' : this.todoService.userNo">
If I enter this number by hand it works great. Todos are filtered by this number.
The problem is that I have two calls in home.ts ionViewLoaded:
//call provider to get all docs to show on the list
this.todoService.getTodos().then((data) => {
this.todos = data;
});
//call provider to get userNo from pouchdb and set variable in the provider
this.todoService.getUser().then((result) => {
console.log("getBadacz result:" + JSON.stringify(result));
this.todoService.userNo = result['name'];
}).then(function(second){;
console.log("second");
});
I need to call getTodos AFTER getUser. So I need to run this functions in sequence using Promises.
Without it this.todoService.userNo in filter is undefined, because it is not set yet. And it will not work.
I tried to do it like this:
this.todoService.getUser().then((result) => {
console.log("getBadacz result:" + JSON.stringify(result));
this.todoService.userNo = result['name'];
}).then(function(second){;
console.log("second");
this.todoService.getTodos().then((data) => {
this.todos = data;
});
});
But there is an error:
EXCEPTION: Error: Uncaught (in promise): TypeError: Cannot read property 'todoService' of null
I tried to arrange this promises in sequence but without success.
Here is fiddle where you can find implementation of functions in provider:
Filter pouchdb docs by userID saved in another doc
Thank you very much for your help.
In situation like this, I would try to include userId in the todo key, that would increase performance (a todos document may have key like this userId_todoId).
So you will not need two promises at all.