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React projects cannot save store? using redux, data
react projects cannot save store? using redux, data
index.js
ReactDOM.render(
<Provider store={store}>
<Router >
< Provider>, document.getElementById( root ))
registerServiceWorker()
actions
export const SET_USER = ...
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.dispatch is not a function
component 1:
const mapDispatchToProps = (dispatch) => {
return {
currency: (data) => dispatch(currency(data)),
}
}
const mapStateToProps = (state) => {
return ({
changeContent: state.changeContent
}
)
}
handleClick = (e...
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React two unrelated components how does component 2 change when component 1 changes a state
I pass values through redux
scenario is when I click on the navigation bar of component 1 and refresh the ajax of component 2
is the data returned by ajax accepted by this.state.contnet
what should I write? There is an urgent need for ideas.
...
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Redux-saga keeps executing action.
rootSaga.js saga Total entry
import { fork, all } from "redux-saga effects";
import { assemblyLineSaga } from "@ routes Devops AssemblyLine saga";
export default function* rootSaga() {
yield all([...assemblyLineSaga]);
yie...
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Switch routes, the timer on the previous page is still running
at the home page, the message prompts you to jump to the Detail component to initialize the data that can only be rendered from Control. Clicking on a new message here will not trigger constructor, so I am dealing with nextProps data. If the time of the ...
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What is the problem with redux-saga triggering action multiple times?
1.rootSaga.js
import { fork, all } from "redux-saga effects";
import sub-sagas from submodules
import { assemblyLineSaga } from "@ routes Devops AssemblyLine saga";
import { DashboardSaga } from "@ routes Devops Dashboard sa...
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How to cancel loading? when an error occurs in a dva request
The loading effect is handled uniformly in dva, but loading cannot be cancelled when an error occurs in the request. What should I do? ...
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How redux updates store twice in a row
update the store data twice in a row, and the second time you will get the original store such as .
initState ={
a: ,
b:
};
dispatch(setState(a,1))
dispatch(setState(b,1))
the final state result is
{
a: ,
b:1
}
if you repla...
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React error report solution!
Warning: Encountered two children with the same key, `.$4`. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and or omitted the behavior is unsupported and could change i...
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Websocket re-new the address after being disconnected. Ws.onmessage has no data.
after WebSocket was disconnected, I re-new a link. In the new connection, I can continue to receive and send data, but I found that ws.onmessage did not return the data after reconnection. I think he is still waiting for the data of the address before ...
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Basic use of redux
realize the function of adding and subtracting numbers by clicking buttons through redux. it doesn t work according to other demo. I don t know what the problem is. Please explain paste the code
below.
...
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After redux calls store.dispatch in the js of the tool class to change the state, the component cannot be updated automatically.
1. The question is as follows: after getting store in any js utility class, the page cannot be updated automatically after the status of store.dispatch (actions), is changed? Can the page be automatically updated only when the state of the dispatch that...
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Is @ connect a grammatical sugar in react-redux? How to use it?
currently only know the traditional usage
const App = connect(
mapStateToProps,
mapDispatchToProps
)(Counter);
but many projects use
@connect(state => ({
value: state.global.value,
extinfo: state.extinfo,
}))
I can understand what i...
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How does reducer get data from the background to initialize store?
I want to write that the value of state is retrieved from the background when reducer, is initialized. How should it be implemented? whether to use redux-thunk directly dispatch a function operation interface or state? that dispat already exists when u...
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Different events in multiple components of React produce the same action
as mentioned, I have a project with multiple components, all of which have some event handling and operations. And different action events within these components may result in the same result, including updates to the redux.
for example, I have two m...
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Why not replace the role of redux-thunk with asynchronous dispatch (action)?
redux-thunk
const fetchData = (params) => (dispatch) => {
setTimeout(() => {
dispatch({action: GET_DATA , payload: 111})
})
}
dispatch
const fetchData = (params) => ({action: GET_DATA , payload: 111});
setTimeout(() =>...
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On the Design of store when developing Multi-page applications with react+react router+redux
recently, I am learning the framework of react. I have only used a single-page application before, but now I want to use it to build a multi-page forum application. If I encounter some questions, I will ask my predecessors to answer them.
I now get th...
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React is a headache to learn, and many concepts don't seem to be clear.
Family bucket
"react": "^16.2.0",
"react-dev-utils": "^5.0.0",
"react-dom": "^16.2.0",
"react-redux": "^5.0.7",
"react-router-dom": "^4.2...
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Redux changes state
component 1
import React from react ;
import {Table} from antd ;
import {connect} from react-redux ;
class Trade extends React.Component {
componentWillMount() {
const data = [
{
key: 1 ,
name: John Brown ,
...
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Reducer has a return value, and no matter how the state of reducer changes, the printed store clock is empty {}
As a matter of fact, there are several questions, which have been stuck for a long time. I don t know why 1. If the state of both reducer has a value, store.subscribe (() = > {
console.log("================store:"+JSON.stringify(store));
});...