I have refactor problems because my code dosnt work to the new versions of angular and angularfire.
Error
The line: upload.url = uploadTask.snapshot.downloadURL; is undefined.
Code
uploadTask.on(firebase.storage.TaskEvent.STATE_CHANGED,
// three observers
// 1.) state_changed observer
(snapshot) => {
// upload in progress
upload.progress = (uploadTask.snapshot.bytesTransferred / uploadTask.snapshot.totalBytes) * 100;
console.log(upload.progress);
},
// 2.) error observer
(error) => {
// upload failed
console.log(error);
},
// 3.) success observer
(): any => {
upload.url = uploadTask.snapshot.downloadURL; //?!?!UNDEFINED
upload.name = upload.file.name;
this.saveFileData(upload);
}
);
Questions
I had tried different solutions from stackoverflow but it dosnt really work. Most of the example is also more about how to retrieve the image but i want to set the variable upload.url to a value.
Another question:
I'm new to angular and web. Will it take long time to change it to firestore? The code is based on realtime firebase.
To get the downloadURL, you have to call the getDownloadURL() method of the Storage Reference Object.
Try this:
uploadTask.snapshot.ref.getDownloadURL()
.subscribe(url => console.log(url))
Related
I am working on react native application I use firebase as my backend. I fetch data from firebase real time database and render it on the page. But now I want my application to be supported offline.
I used following two functions for rendering.
For listings from database
const loadListings = () => {
let data = [];
listingRef.orderByChild("created_at").on("value", (snapshot) => {
data = [];
snapshot.forEach((listing) => {
data.push(listing.val());
});
cache.store("listings", data.slice(0, 10)); // only stores latest ten listings
setListings(data);
setLoading(false);
});
};
and then use it inside useEffect like.
useEffect(() => {
loadListings();
}, []);
and for listings from cache I used this.
const loadListingsCached = async () => {
let data = await cache.get("listings");
setListings(data);
};
Now I cant put a check inside firs function as effect hook will run only one time and initialy network status is null. its not defined.
how do I achieve this?
by the way link to package I used for detecting connectivity
Edit
I used this hook as second argument to useEffect() but didn't work for me
const netInfo = useNetInfo();
I
What you want to achieve is make the code different depending on what is the network status. In the answer linked by #Rohit there is my answer about how to check the network connectivity with Net Info Package.
What you have to do is make the effect dependant on the status change. You should pass it as a argument to the effect.
const netInfo = useNetInfo();
useEffect(() => {
loadListings();
}, [netInfo]);
This way the code will always run when a network change is detected. I hope this is what you wanted to achive. Please be more specific about you goal and what is the problem. Current questions does not specify if the hook is not working, or the rendering function does not trigger etc.
i am new in Vue JS and in Firebase. My target is get all 'eventos' that has same category. I mean, let's i have two eventos, an eventos category "SMIX" and another has "DAM". Now i want to get the eventos has category 'SMIX'
My data structure is here :
created() {
var datos = []
firebase.database().ref('usuarios').on("value", data => {
data.forEach(function(user){
user.child("eventos").orderByChild("categoria").equalTo("SMIX")
.forEach(function(evento){
datos.push(evento.val())
});
});
this.eventos = datos;
});
}[My data Structure][1]
There are several errors and points to be noted in your code:
Firstly, if you receive the error user.child(...).orderByChild is not a function
it is because with data.forEach(function(user) {...}), user is a DataSnapshot (see the forEach() doc), and by calling the child() method on this DataSnapshot you get another DataSnapshot... which does not have a orderByChild() method.
The orderByChild() method is a method of a Reference, so you need to do
user.child(...).ref.orderByChild()
using the ref property of the DataSnapshot
Secondly, you cannot do
user.ref.child("eventos").orderByChild("categoria").equalTo("SMIX")
.forEach()
because you need to use the once() or on() methods to get the data at a database location represented by a Reference.
Thirdly, Since you are going to execute several queries within a loop, you need to use the once() method instead of the on() method. The on() method set a listener that continuously "listens for data changes at a particular location."
Finally, note that you need to use Promise.all() to manage the parallel asynchronous queries to the database.
So, having noted all the points above, the following code will do the trick (to put in created()):
var datos = []
firebase.database().ref('usuarios').once('value')
.then(dataSnapshot => {
var promises = [];
dataSnapshot.forEach(user => {
promises.push(user.ref.child("eventos").orderByChild("categoria").equalTo("SMIX").once('value'));
});
return Promise.all(promises);
})
.then(results => {
//console.log(results);
results.forEach(dataSnapshot => {
dataSnapshot.forEach(evento => {
datos.push(evento.val());
});
});
this.eventos = datos;
});
I need to add current system time into child data field.
I'm using TypeScript, but this might still give you and idea how you could do it.
My code uses the event.timestamp property to get date and time:
export const onWrite = functions.database.ref('/{databaseName}/{tableName}/{key}').onCreate((event) => {
let ref = event.data.ref;
let isCreate = event.eventType == 'providers/google.firebase.database/eventTypes/ref.create';
ref.once('value').then(e => {
// Cloud functions are sometimes executed with a delay and the record might not exist anymore.
if (e.val() === null) {
return;
}
if (isCreate) {
return ref.update({
'createdDateTime': event.timestamp
});
}
});
});
The created events for clients won't include this added data yet, only a later change event does.
I'm haven't investigated yet if this can be fixed (perhaps by making use of transaction).
I saw your image description and understood u want to add system time into firebase.
If you want to do you can do that by , like below
var fb_db=firebase.database().ref('treeName');
var key=fb_db.push().key;
var updatenode={}
updatenode[key+"\"]= new Date();
fb_db.update(updatenode).then(function(){
alert("Success")
})
I use a Cloud Function to generate a short unique URL on a record on the 'onWrite' event, and save it. This works well, but when I save a record from my Ember app using EmberFire, I do get a model back as an argument to a callback, but the URL of this model is undefined. Is there a way to return this back to the client? Or do I need to query the record to get the generated URL?
This is how my Cloud Function code looks:
exports.generateUrl = functions.database.ref('/tournaments/{tid}')
.onWrite(event => {
if (event.data.previous.exists()) {
return;
}
if (!event.data.exists()) {
return;
}
const url = shortid.generate();
return event.data.ref.update({ url });
});
Here is my component that saves data through form submission. I'm using an add-on called ember-changeset to handle some validations, but this shouldn't be related to the issue.
export default Ember.Component.extend({
submit(e) {
e.preventDefault();
let snapshot = this.changeset.snapshot();
return this.changeset
.cast(Object.keys(this.get('schema')))
.validate()
.then(() => {
if (this.changeset.get('isValid')) {
return this.changeset
.save()
.then((result) => {
// Here, result.get('url') is undefined.
})
}
})
}
});
If you have a function that writes new data back to a location in the database after a write, you'll have to keep listening to that location on the client in order to get that data back. Don't use a one-time read (once()), use a persistent listener (on()), and in that listener, make sure you're getting the URL or whatever you expect to be generated by the function. Then remove that listener if you don't need it any more.
(Sorry, I don't know Ember or what abstractions it provides around Realtime Database - I'm giving you the plain JavaScript API methods you'd use on a reference.)
Is there a way to update a part of the URL reactively without using FlowRouter.go() while using React and react-layout?
I want to change the value in the document that is used to get the document from the DB. For example, if I have a route like ~/users/:username and update the username field in the document, I then have to user FlowRouter.go('profile', {data}) to direct the user to that new URL. The "old" route is gone.
Below is the working version I have, but there are two issues:
I have to use FlowRouter.go(), which is actually a full page refresh (and going back would be a 404).
I still get errors in the console because for a brief moment the reactive data for the component is actually wrong.
Relevant parts of the component are like this:
...
mixins: [ReactMeteorData],
getMeteorData() {
let data = {};
let users = Meteor.subscribe('user', {this.props.username});
if (user.ready())
data.user = user;
return data;
}
...
updateName(username) {
Users.update({_id:this.data.user._id}, {$set:{username}}, null, (e,r) => {
if (!e)
FlowRouter.go('profile', {username});
});
},
...
The route is like this:
FlowRouter.route('/users/:username', {
name: 'profile',
action(params) {
ReactLayout.render(Main, {content: <UserProfile {...params} />});
}
});
The errors I get in the console are:
Exception from Tracker recompute function:
and
TypeError: Cannot read property '_id' of undefined