I'm using AWS amplify with my Vue.js application which has a player state that stores player data from the player table from the GraphQL API. I'd like to update the state on player data update in table by using triggers or subscriptions. Can anyone help please?
You can use subscription provided by AppSync GraphQL. It will handle DynamoDB trigger itself.
import { API, graphqlOperation } from "aws-amplify";
import { onUpdatePlayer } from "../../graphql/subscriptions";
Here's Reactjs specific code
const PlayerComponent = () => {
let subscriptionOnUpdate;
const setupSubscriptions = () => {
subscriptionOnUpdate = API.graphql(
graphqlOperation(onUpdatePlayer)
).subscribe({
next: () => {
// do stuff like updating other state
},
})
}
useEffect(() => {
setupSubscriptions();
return () => {
subscriptionOnUpdate.unsubscribe()
}
}, [])
}
Related
I'm building a React Native app, using Redux and AsyncStorage. When a user deletes an item, updates happen a bit slow (2-3 seconds).
I have an array of objects (rather small).
I delete an item in this array with such function:
let idFordeleteFav = categoryArrFav.map(function(el) {return el['name']}).indexOf(itemName)
let cleanedCategory = [...categoryArrFav.slice(0, idFordeleteFav), ...categoryArrFav.slice(idFordeleteFav+1)]
let completeNewList = {...allAffirmation, [category]: cleanedCategory}
props.dispatch(setAffArr(completeNewList))
My mapStateToProps looks like this:
const mapStateToProps = (state) => {
const { appR } = state
return {
allAffirmation: appR.allAffirmation,
affirmations: appR.affirmations}
}
I wonder, what I can do to update faster.
First of all, check how much middleware you have and the logic inside them. Also, I recommend you replace async storage with react native MMKV (https://github.com/mrousavy/react-native-mmkv) which is much faster:
You need to do 2 things. First, create a wrapper for MMKV because it is sync:
import { Storage } from 'redux-persist'
import { MMKV } from "react-native-mmkv"
const storage = new MMKV()
export const reduxStorage: Storage = {
setItem: (key, value) => {
storage.set(key, value)
return Promise.resolve(true)
},
getItem: (key) => {
const value = storage.getString(key)
return Promise.resolve(value)
},
removeItem: (key) => {
storage.delete(key)
return Promise.resolve()
},
}
The second step is migration from the async store for existing users if you have https://github.com/mrousavy/react-native-mmkv/blob/master/docs/MIGRATE_FROM_ASYNC_STORAGE.md
Im working with my friends on a app project and we find an issue many times when we tring to set a use state and the console log the variable, i've looking for a solution in the website and saw that the reason is that the usestate is an async awiat which means the variable that i set in the use state isn't immidatly set in it, so i tried many solution that i found in the websites but none of them work for me.
in the screenShot you can see that the json variable is in console log before and the set varaible doesn't show after the setActiveUser , any help?
Thanks!
If you want to do something upon setting state then your best bet is to use the useEffect hook from React and adding your state in the dependency array. This will then call the function in your useEffect every time the state changes. See below a rough example:
import { Text } from 'react-native';
const MyComponent = () => {
const [activeUser, setActiveUser] = useState(null);
useEffect(() => {
// This should log every time activeUser changes
console.log({ activeUser });
}, [activeUser]);
const fetchAuthentication = async user => {
var flag = false;
await fetch('/api/authUser/', {
method: 'PUT',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify(user),
})
.then(res => {
res.ok && (flag = true);
return res.json();
})
.then(json => {
if (flag) {
setActiveUser(json);
}
})
.catch(error => console.error(error));
return flag;
};
return <Text>Hi</Text>;
};
Full documentation: https://reactjs.org/docs/hooks-effect.html
I have a portfolio site built using NuxtJS and a headless Wordpress CMS. On several pages, I'm importing a mixin that looks like this:
import { mapActions, mapState } from 'vuex';
export default {
computed: {
...mapState({
galleries: state => state.portfolio.galleries[0],
})
},
methods: {
...mapActions('portfolio', ['fetchGalleries']),
},
async fetch() {
await this.fetchGalleries();
}
}
The Vuex module looks like this:
export const state = () => ({
galleries: [],
});
export const actions = {
async fetchGalleries({ commit }) {
let res = await this.$axios.$get(`${process.env.WP_API_URL}/wp/v2/media`);
const data = res.reduce((acc, item) => {
const { slug } = item.acf.category;
(acc[slug] || (acc[slug] = [])).push(item);
return acc;
}, {});
commit('setGalleries', data);
}
};
export const mutations = {
setGalleries(state, data) {
state.galleries.push(data);
}
};
fetch is being used in the mixin to return data from the api before page load. I noticed however that each time I navigate to a new page, it's running that same fetch and continually adding duplicate data to Vuex state.
How do I prevent fetch from running and continually adding duplicate data to my state if it already exists?
I'm not sure why this was tripping me up so much, but I figured out a very simple solution.
async fetch() {
if (this.galleries.length) return;
await this.fetchGalleries();
}
Just added a conditional return statement as the first line within the fetch function.
I'm struggling to implement an EDIT_DETAILS feature in vuex but I can implement this without using vuex but I prefer to use vuex because I am practicing my vuex skills.
Below snippets are the code that I am using to make my edit feature work.
this is in my profile.vue
editUser(id) {
this.id = id;
let details = {
id: this.id,
FULL_NAME: this.personDetails[0].FULL_NAME,
EMAIL: this.personDetails[0].EMAIL
};
//this will pass the details to my actions in vuex
this.editDetails(details);
}
personDetails, just retrieves the details of my user in my database.
id is the user number which is the primary key of my table in my backend.
below is the example json came from my database
this is my action in my vuex:
async editDetails({ commit }, payload) {
try {
const response = await axios.put("http:/localhost:9001/profile/edit/" + payload);
commit("EDIT_DETAILS", response.data);
} catch (err) {
console.log(err);
}
}
and this is my mutation:
EDIT_DETAILS(state, detail) {
state.details.findIndex((param) => param.id === detail);
let details = state.details
details.splice(details.indexOf(detail), 1)
state.details = details.body
}
and my state:
details: [],
Use a comma instead of plus in your axios request
Not sure what your response is but this does nothing
state.details.findIndex((param) => param.id === detail);
You need to push into array if not exists
I'm currently working on a new Vue.js application. It depends heavily on api calls to my backend database.
For a lot of things I use Vuex stores because it manages shared data between my components. When looking at other Vue projects on github I see a special vuex directory with files that handles all the actions, states and so on. So when a component has to call the API, it includes the actions file from the vuex directory.
But, for messages for example, I don't want to use Vuex because those data is only important for one specific view. I want to use the component specific data here. But here is my problem: I still need to query my api. But I shouldn't include the Vuex actions file. So in that way I should create a new actions file. This way I have a specific file with api actions for vuex and for single components.
How should I structure this? Creating a new directory 'api' that handles actions for both vuex data and component-specific data? Or separate it?
I am using axios as HTTP client for making api calls, I have created a gateways folder in my src folder and I have put files for each backend, creating axios instances, like following
myApi.js
import axios from 'axios'
export default axios.create({
baseURL: 'http://localhost:3000/api/v1',
timeout: 5000,
headers: {
'X-Auth-Token': 'f2b6637ddf355a476918940289c0be016a4fe99e3b69c83d',
'Content-Type': 'application/json'
}
})
Now in your component, You can have a function which will fetch data from the api like following:
methods: {
getProducts () {
myApi.get('products?id=' + prodId).then(response => this.product = response.data)
}
}
Similarly you can use this to get data for your vuex store as well.
Edited
If you are maintaining product related data in a dedicate vuex module,
you can dispatch an action from the method in component, which will internally call the backend API and populate data in the store, code will look something like following:
Code in component:
methods: {
getProducts (prodId) {
this.$store.dispatch('FETCH_PRODUCTS', prodId)
}
}
Code in vuex store:
import myApi from '../../gateways/my-api'
const state = {
products: []
}
const actions = {
FETCH_PRODUCTS: (state, prodId) => {
myApi.get('products?id=' + prodId).then(response => state.commit('SET_PRODUCTS', response))
}
}
// mutations
const mutations = {
SET_PRODUCTS: (state, data) => {
state.products = Object.assign({}, response.data)
}
}
const getters = {
}
export default {
state,
mutations,
actions,
getters
}
Note: vue-resource is retired ! Use something else, such as Axios.
I'm using mostly Vue Resource.I create services directory, and there put all connections to endpoints, for e.g PostService.js
import Vue from 'vue'
export default {
get(id) {
return Vue.http.get(`/api/post/${id}`)
},
create() {
return Vue.http.post('/api/posts')
}
// etc
}
Then in my file I'm importing that service and create method that would call method from service file
SomeView.vue
import PostService from '../services/PostService'
export default {
data() {
item: []
},
created() {
this.fetchItem()
},
methods: {
fetchItem() {
return PostService.get(to.params.id)
.then(result => {
this.item = result.json()
})
}
}
}
Based on concept of Belmin Bedak`s answer, i have wrapped it all into a simple library:
https://github.com/robsontenorio/vue-api-query
You can request your API like this:
All results
// GET /posts?filter[status]=ACTIVE
let post = await Post
.where('status', 'ACTIVE')
.get()
Specific result
// GET /posts/1
let post = await Post.find(1)
Editing
// PUT /posts/1
post.title = 'Awsome!'
post.save()
Relationships
// GET /users/1
let user = await User.find(1)
// GET users/1/posts
let posts = await user
.posts()
.get()