How to wait for query to end in aws amplify - amazon-web-services

I query 'product' on one of my screens using the following function
const getProduct = async () => {
try{
if(userId){
await DataStore.query(Product, c=>c.userID("eq", userId)).then(setProducts)
}
}catch(e){
return
}
};
But what I want is to display something like an activity indicator and wait for the query to finish and then display the products. How can I do this?

Your code above should be inside a useEffect() hook that will run any time the userId changes. That hook can return multiple states: loading, error, the data...
To get the above in a very well tested, easier to read, package with bells & whistles (e.g. caching), look into React Query.
Pseudo-code:
function ExampleComponent() {
const { isLoading, error, data } = useQuery(['products'], () =>
// fetch data here
)
if (isLoading) return 'Loading...'
if (error) return 'An error has occurred: ' + error.message
return (
<div>
<!-- map over your data here -->
</div>
)
}

There is nothing extra needed to enable indicator, it's just a visual representation on the client to show that request is in progress. You can enable indicator before query and set it disabled within the setProducts

Related

How to update local data after mutation?

I want to find a better way to update local component state after executing mutation. I'm using svelte-apollo but my question is about basic principles. I have watchQuery which get list of items and returns ObservableQuery in component.
query GetItems($sort: String, $search: String!) {
items(
sort: $sort
where: { name_contains: $search }
) {
id
name
item_picture{
pictures{
url
previewUrl
}
}
description
created_at
}
}
In component I call it:
<script>
$: query = GetItems({
variables: {
sort: 'created_at:DESC',
search
}
});
</script>
...
{#each $query.data?.items || [] as item, key (item.id)}
<div>
<Item
deleteItem={dropItem}
item={item}
setActiveItem={setActiveItem}
/>
</div>
{/each}
...
And I have addItem mutation.
mutation addItem($name: String!, $description: String) {
createItem(
input: { data: { name: $name, description: $description } }
) {
item {
name
description
}
}
}
I just simply want to update local state and add new item to an observable query result after addItem mutation, without using refetchQueries (because I don't want to get all list by network when I just added one item).
I seen this item in cache but my view is not updated.
P.S. If you have similar problems and some ways to solve it, be glad to see some cases from you.
I believe in this case, you could use the cache.modify function to modify the cache directly if you’re looking to skip the network request from refetchQueries. Would that work for your use case? https://www.apollographql.com/docs/react/data/mutations/#making-all-other-cache-updates
If you don’t mind the network request, I like using cache.evict to evict the data in the cache that I know changed personally. I prefer that to refetchQueries in most cases because it refetches all queries that used that piece of data, not just the queries I specify.

in the apollo-client how I may be able to log or intercept all the operations (queries and mutations)

For analytic purposes I'd like to keep track on the client side of all the graphql operations (including ie #client ones). I was unable to find appropriate options in the API and wonder if this may be doable on the apollo-client level or may I need to introduce some proxy to intercept the calls by my own?
A custom Apollo link is a way to go.
You can use apollo-link-logger in particular to log all operations to console.
Usage (from docs):
import apolloLogger from 'apollo-link-logger';
// ...
ApolloLink.from([
apolloLogger,
// ...
]);
Note: Place apolloLogger before other links.
Output example:
As the answer from Yuriy was exactly what I was looking for I marked is as accepted answer - Thanks!
Still for the record here is the code doing a job for me - I believe someone may find it useful, also it is worth to show it's simplicity.
It's worth noting that Apollo links are chainable - thus the argument to a link function are operation: Operation and forward: NextLink which is supposed to be called from our link implementation.
let analytics: Analytics; // this is Fabric.io Analytics to be provided by DI
const analyticsLink = new ApolloLink((
operation: Operation,
forward?: NextLink
) => {
const operationType = operation.query.definitions[0].operation;
return forward(operation)
.map((result: FetchResult) => {
try {
analytics.sendCustomEvent(`${operationType}.${operation.operationName}`);
} catch (e) {
console.error('analytics error', e);
}
return result;
});
});
as a bonus we can also catch errors (i.e. to leverage fabric.io crashlytics) by using apollo-link-error (handling of errors in Apollo is a bit more complex);
const analyticsErrorLink = onError((error: ErrorResponse) => {
try {
// it's worth to rethink what we wanna log here
const message = error.graphQLErrors ? error.graphQLErrors[0].message :
(error.networkError.name + ': ' + error.networkError.message);
analytics.sendNonFatalCrash('GraphQL error: ' + message);
} catch(e) {
console.error('cannot report error to analytics', e);
}
});
Finally to compose the links we should put our intercepting implementations at the beginning so we will be able to catch all the GraphQL operations including those marked with #client which are not reaching network link - in my case full link looks like:
ApolloLink.from([
analyticsErrorLink,
analyticsLink,
stateLink,
auth,
http])

Ember makes unwanted call to backend in model hook

I want to be able to retrieve a certain conversation when its id is entered in the URL. If the conversation does not exist, I want to display an alert message with a record not found.
here is my model hook :
model: function(params){
return this.store.filter('conversation', { status : params.status}, function(rec){
if(params.status == 'all'){
return ((rec.get('status') === 'opened' || rec.get('status') === 'closed'));
}
else{
return (rec.get('status') === params.status); <--- Problem is here
}
});
}
For example, if I want to access a certain conversation directly, I could do :
dev.rails.local:3000/conversations/email.l#email.com#/convid
The problem is when I enter a conversation id which doesn't exist (like asdfasdf), ember makes call to an inexisting backend route.
It makes a call to GET conversation/asdfasdf. I'm about sure that it is only due to the record not existing. I have nested resources in my router so I'm also about sure that it tries to retrieve the conversation with a non existing id.
Basically, I want to verify the existence of the conversation before returning something from my hook. Keep in mind that my model hook is pretty much set and won't change, except for adding a validation on the existence of the conversation with the id in the url. The reason behind this is that the project is almost complete and everything is based on this hook.
Here is my router (some people are going to tell me you can't use nested resources, but I'm doing it and it is gonna stay like that so I have to work with it because I'm working on a project and I have to integrate ember in this section only and I have to use this setup) :
App.Router.map(function(){
// Routing list to raw namespace path
this.resource('conversations', { path : '/' }, function() {
this.resource('conversation', { path : '/:conversation_id'});
});
});
This also happens when I dont specify any id and I use the hashtag in my url like this :
dev.rails.local:3000/conversations/email.l#email.com#/ would make a call to conversation/
I know it is because of my nested resource. How can I do it?
By passing a query to filter (your { status : params.status}) you are asking Ember Data to do a server query. Try removing it.
From the docs at http://emberjs.com/api/data/classes/DS.Store.html#method_filter:
Optionally you can pass a query, which is the equivalent of calling find with that same query, to fetch additional records from the server. The results returned by the server could then appear in the filter if they match the filter function.
So, remove the query:
model: function(params){
return this.store.filter('conversation', function(rec) {
if (params.status == 'all') {
return rec.get('status') === 'opened' || rec.get('status') === 'closed';
} else {
return rec.get('status') === params.status;
}
});
}
Ok so here is what I did. I removed my nested resource because I realised I wasn't using it for any good reason other than redirecting my url. I decided to manually redirect my url using javascript window.location.
This removed the unwanted call (which was caused by the nested resource).
Thanks to torazaburo, you opened my eyes on many things.

How to forcefully remove a record from the store, and find it again

Whenever my backend replies with an error, I would like to:
Discard the record as it is in the store. I do not care what state the record is in, I just want it out of the store.
Request it again from the backend. The record should be in a normal state now.
Is it possible to do this? Can I do it in a becameError? How?
This is currently my code:
var entry = this.get('content');
this.transaction = this.get('store').transaction();
this.transaction.add(entry);
...
this.transaction.commit();
entry.on('becameError', this, function () { this.handleFailure(); });
And handleFailure:
handleFailure : function() {
console.error('handleFailure > ');
this.transaction.rollback();
this.goBack();
},
What can I do in handleFailure so that the record is forgotten and requested again?
Or, as alternative, how can I clear any flag in the record so that I can continue to use it normally, without getting problems like:
Uncaught Error: Attempted to handle event `becomeDirty` on <SettingsApp.Scvoicemail:ember1027:08b8fc66-cd90-47a1-9053-4f6fefabdfe3> while in state root.error.
record.unload() is the way to do it, but it wasn't introduced until 1.0 beta, and it's a ton easier without the unnecessary transaction stuff.

Adding item to filtered result from ember-data

I have a DS.Store which uses the DS.RESTAdapter and a ChatMessage object defined as such:
App.ChatMessage = DS.Model.extend({
contents: DS.attr('string'),
roomId: DS.attr('string')
});
Note that a chat message exists in a room (not shown for simplicity), so in my chat messages controller (which extends Ember.ArrayController) I only want to load messages for the room the user is currently in:
loadMessages: function(){
var room_id = App.getPath("current_room.id");
this.set("content", App.store.find(App.ChatMessage, {room_id: room_id});
}
This sets the content to a DS.AdapterPopulatedModelArray and my view happily displays all the returned chat messages in an {{#each}} block.
Now it comes to adding a new message, I have the following in the same controller:
postMessage: function(contents) {
var room_id = App.getPath("current_room.id");
App.store.createRecord(App.ChatMessage, {
contents: contents,
room_id: room_id
});
App.store.commit();
}
This initiates an ajax request to save the message on the server, all good so far, but it doesn't update the view. This pretty much makes sense as it's a filtered result and if I remove the room_id filter on App.store.find then it updates as expected.
Trying this.pushObject(message) with the message record returned from App.store.createRecord raises an error.
How do I manually add the item to the results? There doesn't seem to be a way as far as I can tell as both DS.AdapterPopulatedModelArray and DS.FilteredModelArray are immutable.
so couple of thoughts:
(reference: https://github.com/emberjs/data/issues/190)
how to listen for new records in the datastore
a normal Model.find()/findQuery() will return you an AdapterPopulatedModelArray, but that array will stand on its own... it wont know that anything new has been loaded into the database
a Model.find() with no params (or store.findAll()) will return you ALL records a FilteredModelArray, and ember-data will "register" it into a list, and any new records loaded into the database will be added to this array.
calling Model.filter(func) will give you back a FilteredModelArray, which is also registered with the store... and any new records in the store will cause ember-data to "updateModelArrays", meaning it will call your filter function with the new record, and if you return true, then it will stick it into your existing array.
SO WHAT I ENDED UP DOING: was immediately after creating the store, I call store.findAll(), which gives me back an array of all models for a type... and I attach that to the store... then anywhere else in the code, I can addArrayObservers to those lists.. something like:
App.MyModel = DS.Model.extend()
App.store = DS.Store.create()
App.store.allMyModels = App.store.findAll(App.MyModel)
//some other place in the app... a list controller perhaps
App.store.allMyModels.addArrayObserver({
arrayWillChange: function(arr, start, removeCount, addCount) {}
arrayDidChange: function(arr, start, removeCount, addCount) {}
})
how to push a model into one of those "immutable" arrays:
First to note: all Ember-Data Model instances (records) have a clientId property... which is a unique integer that identifies the model in the datastore cache whether or not it has a real server-id yet (example: right after doing a Model.createRecord).
so the AdapterPopulatedModelArray itself has a "content" property... which is an array of these clientId's... and when you iterate over the AdapterPopulatedModelArray, the iterator loops over these clientId's and hands you back the full model instances (records) that map to each clientId.
SO WHAT I HAVE DONE
(this doesn't mean it's "right"!) is to watch those findAll arrays, and push new clientId's into the content property of the AdapterPopulatedModelArray... SOMETHING LIKE:
arrayDidChange:function(arr, start, removeCount, addCount){
if (addCount == 0) {return;} //only care about adds right now... not removes...
arr.slice(start, start+addCount).forEach(function(item) {
//push clientId of this item into AdapterPopulatedModelArray content list
self.getPath('list.content').pushObject(item.get('clientId'));
});
}
what I can say is: "its working for me" :) will it break on the next ember-data update? totally possible
For those still struggling with this, you can get yourself a dynamic DS.FilteredArray instead of a static DS.AdapterPopulatedRecordArray by using the store.filter method. It takes 3 parameters: type, query and finally a filter callback.
loadMessages: function() {
var self = this,
room_id = App.getPath('current_room.id');
this.store.filter(App.ChatMessage, {room_id: room_id}, function (msg) {
return msg.get('roomId') === room_id;
})
// set content only after promise has resolved
.then(function (messages) {
self.set('content', messages);
});
}
You could also do this in the model hook without the extra clutter, because the model hook will accept a promise directly:
model: function() {
var self = this,
room_id = App.getPath("current_room.id");
return this.store.filter(App.ChatMessage, {room_id: room_id}, function (msg) {
return msg.get('roomId') === room_id;
});
}
My reading of the source (DS.Store.find) shows that what you'd actually be receiving in this instance is an AdapterPopulatedModelArray. A FilteredModelArray would auto-update as you create records. There are passing tests for this behaviour.
As of ember.data 1.13 store.filter was marked for removal, see the following ember blog post.
The feature was made available as a mixin. The GitHub page contains the following note
We recommend that you refactor away from using this addon. Below is a short guide for the three filter use scenarios and how to best refactor each.
Why? Simply put, it's far more performant (and not a memory leak) for you to manage filtering yourself via a specialized computed property tailored specifically for your needs