The goal is to repeatedly fetch generation data when the Id changes...The generation Id changes at the backend
Only AFTER I used redux tool kit and createAsyncThunk, did it stop refreshing generation Id automatically, unless I manually refresh the page (will it show the latest generationId)
The change I've made, so how should I do it? Thanks.
in generationSlice.js
export const getGeneration = createAsyncThunk(
'generation/getGeneration',
async () => {
try {
const resp = await axios(url)
return resp.data
} catch (error) {
return error.response
}
}
)
and
in components/Generation.js
const { generationId, expiration, isLoading } = useSelector((store) => {
return store.generation
})
const dispatch = useDispatch()
useEffect(() => {
dispatch(getGeneration())
}, [generationId])
Related
My react app uses a redux connected component to render data from backend for a project page, so I called a GET dispatch inside a React Hook useEffect to make sure data is always rendered when the project page first open, and whenever there is a change in state project, the component will be updated accordingly using connect redux function. However, the component doesn't update after I reduce the new state using a DELETE API request, only if I dispatch another GET request then the state will be updated. So I have to call 2 dispatches, one for DELETE and one for GET to get the page updated synchronously (as you can see in handleDeleteUpdate function), and the same thing happened when I dispatch a POST request to add an update (in handleProjectUpdate). Only when I reload the page, the newly changed data will show up otherwise it doesn't happen synchronously, anyone knows what's wrong with the state update in my code? and how can I fix this so the page can be loaded faster with only one request?
I've changed the reducer to make sure the state is not mutated and is updated correctly.
I have also tried using async function in handleDeleteUpdate to make sure the action dispatch is finished
I have tried
console.log(props.project.data.updates)
to print out the updates list after calling props.deleteUpdate but it seems the updates list in the state have never been changed, but when I reload the page, the new updates list is shown up
Here is the code I have for the main connected redux component, actions, and reducers file for the component
function Project(props) {
let options = {year: 'numeric', month: 'long', day: 'numeric', hour: '2-digit', minute: '2-digit'}
const {projectID} = useParams();
const history = useHistory();
console.log(props.project.data? props.project.data.updates : null);
console.log(props.project.data);
// const [updates, setUpdates] = useState(props.project.data? props.project.data.updates : null)
useEffect(() => {
props.getProject(projectID);
}, []);
// Add an update to project is handled here
const handleProjectUpdate = async (updateInfo) => {
await props.postProjectUpdate(projectID, updateInfo)
await props.getProject(projectID);
}
const handleDeleteUpdate = async (updateID) => {
await props.deleteUpdate(projectID, updateID);
await props.getProject(projectID);
console.log(props.project.data.updates);
};
return (
<div>
<Navbar selected='projects'/>
<div className = "project-info-layout">
<UpdateCard
updates = {props.project.data.updates}
handleProjectUpdate = {handleProjectUpdate}
handleDeleteUpdate = {handleDeleteUpdate}
options = {options}
/>
</div>
</div>
)
}
const mapStateToProps = state => ({
project: state.project.project,
});
export default connect(
mapStateToProps,
{getProject, postProjectUpdate, deleteUpdate}
)(Project);
ACTION
import axios from 'axios';
import { GET_PROJECT_SUCCESS,ADD_PROJECT_UPDATE_SUCCESS, DELETE_PROJECT_UPDATE_SUCCESS} from './types';
let token = localStorage.getItem("token");
const config = {
headers: {
Authorization: `Token ${token}`,
}
};
export const getProject = (slug) => dispatch => {
axios.get(`${backend}/api/projects/` + slug, config)
.then(
res => {
dispatch({
type: GET_PROJECT_SUCCESS,
payload: res.data,
});
},
).catch(err => console.log(err));
}
export const postProjectUpdate = (slug, updateData) => dispatch => {
axios.post(`${backend}/api/projects/`+slug+ `/updates`,updateData, config)
.then(
res => {
dispatch({
type: ADD_PROJECT_UPDATE_SUCCESS,
payload: res.data,
});
},
).catch(err => console.log(err));
}
export const deleteUpdate = (slug, updateID) => dispatch => {
axios.delete(`${backend}/api/projects/`+ slug + `/updates/`+ updateID, config)
.then(
res => {
dispatch({
type: DELETE_PROJECT_UPDATE_SUCCESS,
payload: updateID,
});
},
).catch(err => console.log(err));
}
Reducer
import { GET_PROJECT_SUCCESS,ADD_PROJECT_UPDATE_SUCCESS, DELETE_PROJECT_UPDATE_SUCCESS} from "../actions/types";
const initialState = {
project: {},
};
export default function ProjectReducer(state = initialState, action) {
const { type, payload } = action;
switch (type) {
case GET_PROJECT_SUCCESS:
return {
...state, // return all initial state
project: payload
};
case ADD_PROJECT_UPDATE_SUCCESS:
return {
...state,
project: {
...state.project,
updates: [...state.project.data.updates, payload.data]
}
};
case DELETE_PROJECT_UPDATE_SUCCESS:
let newUpdatesArray = [...state.project.updates]
newUpdatesArray.filter(update => update.uuid !== payload)
return {
...state,
project: {
...state.project,
members: newUpdatesArray
}
};
default:
return state;
}
}
updateCard in the Project component is showing a list of all updates
const accounts = await web3.eth.getAccounts();
App = {
load: async () => {
await App.loadWeb3(
await App.loadAccount()
)
},
loadWeb3: async () => {
if (typeof web3 !== 'undefined') {
App.web3Provider = web3.currentProvider
web3 = new Web3(web3.currentProvider)
} else {
window.alert("Please connect to Metamask.")
}
// Modern dapp browsers...
if (window.ethereum) {
window.web3 = new Web3(ethereum)
try {
// Request account access if needed
await ethereum.enable()
// Acccounts now exposed
web3.eth.sendTransaction({/* ... */})
} catch (error) {
// User denied account access...
}
}
// Legacy dapp browsers...
else if (window.web3) {
App.web3Provider = web3.currentProvider
window.web3 = new Web3(web3.currentProvider)
// Acccounts always exposed
web3.eth.sendTransaction({/* ... */})
}
// Non-dapp browsers...
else {
console.log('Non-Ethereum browser detected. You should consider trying MetaMask!')
}
},
loadAccount: async () => {
App.account = web3.eth.accounts[0]
console.log(App.account)
}
}
$(() => {
$(window).load(() => {
App.load()
})
})
The error is in LINE 1 where I get the accounts from Ganache but await is valid only for async.
What changes should I make in this code to remove the error? Please help me.
If I remove this line the error says that it cannot access accounts and after this await does not work.
Is there any way to make this piece of code in the form of an ASYNC function?
await calls can only be made in functions marked as async. As you have used await in line 1 it is not wrapped in an async function. You can wrap your code in a async function and then call that function. e.g something like:
const main = async () => { // <- the async wrapper function
const accounts = await web3.eth.getAccounts();
// .... rest of your code
$(() => {
$(window).load(() => {
App.load()
})
})
}
main()
Or if you want to be more advanced and not save the function at all
(async ()=>{
const accounts = await web3.eth.getAccounts();
// .... rest of your code
})() // <- call the function right after declaring it
I'm new to next js. And I have one user.js file inside of my pages directory in next.js. This is the source code:
// pages/user.js
function user(props) {
const [userList, setUserList] = useState([])
const [roleList, setRoleList] = useState([])
async function initialFetch() {
const userList = await fetch('GET', GET_ALL_USERS)
setUserList(userList)
const roleList = await fetch('GET', GET_ALL_ROLES)
setRoleList(roleList)
console.log('userList in async')
console.log(userList)
}
if (!props.userList.status) {
initialFetch()
} else {
setUserList(props.userList)
setRoleList(props.roleList)
}
console.log('userList outside')
console.log(userList)
return (
<>
<TableUserManagement users={userList} roles={roleList}/>
</>
)
};
user.getInitialProps = async (ctx) => {
const userList = await fetch('GET', GET_ALL_USERS)
const roleList = await fetch('GET', GET_ALL_ROLES)
return {userList, roleList}
}
The problem is that above async initialFetch() function is always called uninfinitively :
So what am I doing wrong here? Thank you
Note: I have tried to use useEffect() but the looping still happening. This the code :
useEffect(
() => {
if (!props.userList.status) {
initialFetch()
} else {
setUserList(props.userList)
setRoleList(props.roleList)
}
console.log('user list diliuar')
console.log(userList)
}
)
This issue is not related to Next.js but React itself. This is the code that cause unfinite calls:
if (!props.userList.status) {
initialFetch()
} else {
setUserList(props.userList)
setRoleList(props.roleList)
}
Since after setting any state, your component re-renders and that part of code keeps running again, and the fetch cause setting state again,... that loops forever.
You should move you data-fetching logic in side componentDidMount or useEffect. Remember to provide the dependency array of useEffect. In this case, you may only need to fetch data only once so you should provide the empty dependency array.
useEffect(() => {
async function initialFetch() {
const userList = await fetch('GET', GET_ALL_USERS)
setUserList(userList)
const roleList = await fetch('GET', GET_ALL_ROLES)
setRoleList(roleList)
}
if (!props.userList.status) {
initialFetch()
} else {
setUserList(props.userList)
setRoleList(props.roleList)
}
}, []);
P/s: you should name you React component in PascalCase (ex: User)
app.js
const mapStateToProps = (state) => {
return {home:state}
}
const mapDispatchToProps = (dispatch) => {
return {
guestLogin: (data)=>{dispatch(guestLogin(data)).then(()=>{
dispatch(initiateTrans(stateProps.home))
})},
};
}
const mergeProps = (stateProps, dispatchProps, ownProps) => {
return Object.assign({}, ownProps, stateProps, dispatchProps,{
initiateTrans: () => dispatchProps.initiateTrans(stateProps.home),
})
}
Action.js
export const guestLogin= (state)=>{
var data={
'email':state.email,
'name':state.name,
'phone_number':state.ph_number,
'phone_code':state.country_code
}
return function(dispatch) {
return dataservice.guestSignup(data).then(res => {
dispatch(afterLoggedGuest(res))
}).catch(error => {
throw(error);
});
}
}
function afterLoggedGuest(result) {
return {type: guestLoginChange, result};
}
export const initiateTrans= (updatedState)=>{
return function(dispatch) {
return dataservice.initiateTransaction(updatedState).then(res => {
console.log("initiateTransaction",res)
}).catch(error => {
throw(error);
});
}
}
Reducer.js
if(action.type === guestLoginChange){
return {
...state,guestData: {
...state.guestData,
Authorization: action.result.authentication ,
auth_token: action.result.auth_token ,
platform: action.result.platform
} ,
}
}
I am having two api requests.. After first api request success i want to update state value then pass that updated state to another api request..
I tried to get the updted props
how to dispatch the initiateTrans with update props
I need to update value at api request success in call back i need to call one more request with updated state value
currently i am not able to get the update props value
I think this is a good use case for thunk (redux-thunk), which is a middleware that allows you to execute multiple dispatches in an action.
You will need to apply the middleware when you configure the initial store (see docs on link above). But then in your actions, you can wrap the code with a dispatch return statement, which gives you access to multiple calls. For example:
export const guestLogin= (state)=>{
return dispatch => {
var data={...} // some data in here
return dataservice.guestSignup(data).then(res => {
dispatch(afterLoggedGuest(res))
}).catch(error => {
throw(error);
// could dispatch here as well...
});
}
}
I'm having a real hard time understanding how to implement aor-realtime (trying to use it with firebase; reads only, no write).
The first place I get stuck: This library generates a saga, right? How do I connect that with a restClient/resource? I have a few custom sagas that alert me on errors, but there is a main restClient/resource backing those. Those sagas just handles some side-effects. In this case, I just don't understand what the role of the client is, and how it interacts with the generated saga (or visa-versa)
The other question is with persistence: Updates stream in and the initial set of records is not loaded in one go. Should I be calling observer.next() with each update? or cache the updated records and call next() with the entire collection to-date.
Here's my current attempt at doing the later, but I'm still lost with how to connect it to my Admin/Resource.
import realtimeSaga from 'aor-realtime';
import { client, getToken } from '../firebase';
import { union } from 'lodash'
let cachedToken
const observeRequest = path => (type, resource, params) => {
// Filtering so that only chats are updated in real time
if (resource !== 'chat') return;
let results = {}
let ids = []
return {
subscribe(observer) {
let databaseRef = client.database().ref(path).orderByChild('at')
let events = [ 'child_added', 'child_changed' ]
events.forEach(e => {
databaseRef.on(e, ({ key, val }) => {
results[key] = val()
ids = union([ key ], ids)
observer.next(ids.map(id => results[id]))
})
})
const subscription = {
unsubscribe() {
// Clean up after ourselves
databaseRef.off()
results = {}
ids = []
// Notify the saga that we cleaned up everything
observer.complete();
}
};
return subscription;
},
};
};
export default path => realtimeSaga(observeRequest(path));
How do I connect that with a restClient/resource?
Just add the created saga to the custom sagas of your Admin component.
About the restClient, if you need it in your observer, then pass it the function which return your observer as you did with path. That's actually how it's done in the readme.
Should I be calling observer.next() with each update? or cache the updated records and call next() with the entire collection to-date.
It depends on the type parameter which is one of the admin-on-rest fetch types:
CRUD_GET_LIST: you should return the entire collection, updated
CRUD_GET_ONE: you should return the resource specified in params (which should contains its id)
Here's the solution I came up with, with guidance by #gildas:
import realtimeSaga from "aor-realtime";
import { client } from "../../../clients/firebase";
import { union } from "lodash";
const observeRequest = path => {
return (type, resource, params) => {
// Filtering so that only chats are updated in real time
if (resource !== "chats") return;
let results = {}
let ids = []
const updateItem = res => {
results[res.key] = { ...res.val(), id: res.key }
ids = Object.keys(results).sort((a, b) => results[b].at - results[a].at)
}
return {
subscribe(observer) {
const { page, perPage } = params.pagination
const offset = perPage * (page - 1)
const databaseRef = client
.database()
.ref(path)
.orderByChild("at")
.limitToLast(offset + perPage)
const notify = () => observer.next({ data: ids.slice(offset, offset + perPage).map(e => results[e]), total: ids.length + 1 })
databaseRef.once('value', snapshot => {
snapshot.forEach(updateItem)
notify()
})
databaseRef.on('child_changed', res => {
updateItem(res)
notify()
})
const subscription = {
unsubscribe() {
// Clean up after ourselves
databaseRef.off();
// Notify the saga that we cleaned up everything
observer.complete();
}
};
return subscription;
}
};
}
};
export default path => realtimeSaga(observeRequest(path));