I have a issue with fetching json from server. When I'm trying to getState() from store there's "undefined" value. I'm using "redux-thunk". Help!
Store and state:
const store = createStore(reducer, applyMiddleware(thunk));
const initialState = {
datas: [],
loading: false
};
Reducer:
function reducer(state = initialState, action) {
switch(action.type){
case FETCH_DATA_BEGIN:
return {
...state,
loading: true
};
case FETCH_DATA_SUCCESS:
return {
...state,
datas: action.payload.TableData
};
default:
return state;
};
}
Actions:
function fetchData() {
return dispatch => {
dispatch(fetchDataBegin());
return fetch("http://www.blblblblb.com")
.then(res => res.json())
.then(json => {
dispatch(fetchDataSuccess(json.TableData));
return json.TableData;
})
};
}
const FETCH_DATA_SUCCESS = 'FETCH_DATA_SUCCESS';
const fetchDataSuccess = TableData => ({
type: FETCH_DATA_SUCCESS,
payload: {TableData}
});
const FETCH_DATA_BEGIN = 'FETCH_DATA_BEGIN';
const fetchDataBegin = () => ({
type: FETCH_DATA_BEGIN
});
Thanks!
Related
I have a problem with my redux reducer.It doesn't return the expected state after dispatching the getCurrentProfile action, it returns the initial state which is "null" instead of "{}", which is fetched with an ajax request, so when the network return the result the state profile change to the result returned but when it is an error returned it stay null instead of empty object, so that is my code:
enter image description here
profileAcction.js :
import axios from 'axios';
import { GET_PROFILE, PROFILE_LOADING, CLEAR_CURRENT_PROFILE} from './types';
//Loading profile
const setProfileLoading = () => {
return {
type: PROFILE_LOADING
}
};
// Clear current profile
export const clearCurrentProfile = () => {
return {
type: CLEAR_CURRENT_PROFILE,
}
}
// Get current profile
export const getCurrentProfile = () => dispatch => {
dispatch(setProfileLoading());
axios.get('/api/profile')
.then(res => dispatch({
type: GET_PROFILE,
payload: res.data
})).catch(error =>
dispatch({
type: GET_PROFILE,
payload: {}
}))
};
profileReducer.js:
import {GET_PROFILE, PROFILE_LOADING, CLEAR_CURRENT_PROFILE} from '../actions/types';
const initialState = {
profile: null,
profiles: null,
loading: false
};
const profileReducer = (state=initialState, action) => {
switch(action.type) {
case PROFILE_LOADING:
return {
...state,
loading: true
}
case GET_PROFILE:
return {
...state,
profile: action.payload,
loading: false
}
case CLEAR_CURRENT_PROFILE:
return {
...state,
profile: null,
loading: false
}
default:
return state;
}
};
export default profileReducer;
I am struggling with an issue with the custom fetch hook.Simply i am trying to test my fetch hook if the data already fetched the hook needs to get data from cache instead of api.
The test case fails and looks like caching mechanism not working, but if i try on the browser with manual prop change caching mechanism works properly.
import { render, waitFor } from "#testing-library/react";
const renderList = (filterParams = testFilterParamsList[0]) =>
render(<List filterParams={filterParams} />);
it("should re-render without fetch", async () => {
const { rerender } = renderList(testFilterParamsList[0]);
rerender(<List filterParams={testFilterParamsList[1]} />);
expect(window.fetch).toHaveBeenCalledTimes(1);
});
// useFetch.js
import {useEffect, useReducer} from "react";
const cache = {};
const FETCH_REQUEST = "FETCH_REQUEST";
const FETCH_SUCCESS = "FETCH_SUCCESS";
const FETCH_ERROR = "FETCH_SUCCESS";
const INITIAL_STATE = {
isPending: false,
error: null,
data: [],
};
const useFetch = ({url, filterOptions}) => {
const [state, dispatch] = useReducer((state, action) => {
switch (action.type) {
case FETCH_REQUEST:return {...INITIAL_STATE, isPending: true};
case FETCH_SUCCESS: return {...INITIAL_STATE, isPending: false, data: action.payload};
case FETCH_ERROR: return {...INITIAL_STATE, isPending: false, error: action.payload};
default: return state;
}
}, INITIAL_STATE);
useEffect(() => {
const fetchData = async () => {
dispatch({type: FETCH_REQUEST});
if (cache[url]) {
const data = cache[url];
dispatch({type: FETCH_SUCCESS, payload: data});
} else {
try {
const response = await window.fetch(url);
let data = await response.json();
cache[url] = data
dispatch({type: FETCH_SUCCESS, payload: data});
} catch (err) {
dispatch({type: FETCH_ERROR, payload: err});
}
}
};
fetchData();
}, [filterOptions, url]);
return state;
};
export default useFetch;
// List.js
import useFetch from "../hooks/useFetch";
export const RocketsList = ({ filterParams }) => {
const { isPending, error, data } = useFetch({
url: "https://api.spacexdata.com/v3/launches/past",
name:filterParams.name,
});
return (
<div>
Doesn't matter
</div>
);
};
I am working on a MERN app and I have a problem when updating items. I am getting rejections when sending a patch request and there is not much info for debugging to solve the problem. I will appreciate it if someone can point out some logic that is not correct in my code. Thank you in advance.
Here below is the logic I have implemented.
postService.js:
import axios from 'axios';
const API_URL = '/api/posts/';
const updatePost = async (postId, postData, token) => {
const config = {
headers: {
Authorization: `Bearer ${token}`,
},
};
const response = await axios.patch(`${API_URL}/${postId}/`, postData, config);
if (response.data) {
return {
...response.data,
id: postId,
};
}
};
postSlice.js:
import { createSlice, createAsyncThunk } from '#reduxjs/toolkit';
import postService from './postService';
const initialState = {
posts: [],
isError: false,
isSuccess: false,
isLoading: false,
message: '',
};
export const updatePost = createAsyncThunk(
'posts/updatePost',
async (id, postData, thunkAPI) => {
try {
const token = thunkAPI.getState().auth.user.token;
return await postService.updatePost(id, postData, token);
} catch (error) {
const message =
(error.response.data.message) ||
error.toString();
return thunkAPI.rejectWithValue(message);
}
}
);
export const postSlice = createSlice({
name: 'post',
initialState,
reducers: {
reset: (state) => initialState,
},
extraReducers: (builder) => {
builder
.addCase(updatePost.pending, (state) => {
state.isLoading = true;
})
.addCase(updatePost.fulfilled, (state, action) => {
state.isLoading = false;
state.isSuccess = true;
state.posts = state.posts.map((post) =>
post.id === action.payload.id ? action.payload : post
);
})
.addCase(updatePost.rejected, (state, action) => {
state.isLoading = false;
state.isError = true;
state.message = action.payload;
})
});
},
});
export const selectAllPosts = (state) => state.posts.posts;
export const { reset } = postSlice.actions;
export default postSlice.reducer;
Form.js:
const Form = ({ postId, setPostId }) => {
const [formData, setFormData] = useState({
postCreator: '',
title: '',
body: '',
imageFile: '',
});
const dispatch = useDispatch();
const user = JSON.parse(localStorage.getItem('user'));
const post = useSelector((state) =>
postId ? state.posts.posts.find((post) => post._id === postId) : null
);
useEffect(() => {
if (post) setFormData(post);
}, [post]);
const clearPost = () => {
setPostId(0);
setFormData({
postCreator: '',
title: '',
body: '',
imageFile: '',
});
};
const handleSubmit = async (e) => {
e.preventDefault();
if (
!formData.postCreator &&
!formData.title &&
!formData.body &&
!formData.imageFile
) {
toast.warning(
'Please fill out all fields, and make sure you are also logged in'
);
} else if (postId) {
dispatch(updatePost(postId, formData));
console.log(postId);
} else {
dispatch(createPost(formData));
clearPost();
setPostId(null);
}
clearPost();
};
The second param of createAsyncThunk is the payloadCreator.
The first param of the payloadCreator is the arguments. The second param of payloadCreator is thunkAPI.
So you should combine id and postData into a single object to represent the arguments.
Update postSlice.js:
export const updatePost = createAsyncThunk(
'posts/updatePost',
async ({id, postData}, thunkAPI) => {
try {
const token = thunkAPI.getState().auth.user.token;
return await postService.updatePost(id, postData, token);
} catch (error) {
const message =
(error.response.data.message) ||
error.toString();
return thunkAPI.rejectWithValue(message);
}
}
);
Update where you dispatch the updatePost thunk:
updatePost({
id: 123,
postData: {
foo: 'bar'
}
})
I am trying to create a scraping application using redux toolkit for learning purposes but the scraping process fails whenever I pass custom parameters in the dispatch statement but works correctly on passing default parameters in the thunk
My async thunk
export const loadData = createAsyncThunk(
"alldata/getdata",
async ({ pageNo, language }, thunkAPI) => {
const data = await fetch(
`http://localhost:5000/scrape?pageNo=${encodeURIComponent(
pageNo
)}&language=${encodeURIComponent(language)}`
);
const json = data.json();
return json;
}
);
My slice
const projectSlice = createSlice({
name: "allprojects",
state: {
projectState: [],
workingState: [],
isLoading: false,
hasError: false,
},
reducers: {
addProject: (state, action) => {
return state.workingState.push(action.payload);
},
removeProject: (state, action) => {
return state.workingState.filter(
(project) => project.id !== action.payload.id
);
},
},
extraReducers: {
[loadData.pending]: (state, action) => {
state.isLoading = true;
state.hasError = false;
},
[loadData.fulfilled]: (state, action) => {
const { json } = action.payload;
state.isLoading = false;
state.hasError = false;
},
[loadData.rejected]: (state, action) => {
state.isLoading = false;
state.hasError = true;
},
},
});
export const { addProject, removeProject } = projectSlice.actions;
export const { Projectreducer } = projectSlice.reducer;
export const selectAllPosts = (state) => state.allprojects.projectState;
Calling the async action
React.useEffect(() => {
console.log(dispatch(loadData(1, "ruby")));
}, []);
//url:https://github.com/search?p=undefined&q=language%3Aundefined
how do I solve this error
The async thunk arguments must be collected in one object:
dispatch(loadData({ pageNo: 1, language: "ruby" }))
See https://redux-toolkit.js.org/api/createAsyncThunk#payloadcreator
Being a newbie with RN and Redux, I'm confused as to why my props are undefined after reading from AsyncStorage.
I log in, save the state to the store and storage... I reload the app and read from the storage and update the state. The storage is retrieving my object but the props are undefined.
actions.js:
export const getSession = (data) => ({
type: 'GET_SESSION',
payload: {
user: data
}
});
export const getUserSession = () => dispatch => {
return AsyncStorage.getItem('userSession').then((data) => {
console.log('Props at asynsstorage: ', data);
// {"current_user":{"uid":"1","roles":["authenticated","administrator"], ...}
dispatch(loading(false));
dispatch(getSession(data));
})
.catch((err) => {
})
}
reducer.js
import { combineReducers } from 'redux';
const defaultState = {
xcsrf: '',
user: {},
loading: false,
error: '',
};
const authReducer = ( state = defaultState, action ) => {
switch(action.type) {
case 'GET_SESSION':
return {
...state,
user: action.payload.user,
loading: false,
}
case 'SAVE_SESSION':
return {
...state,
user: action.payload.user,
loading: false,
}
default:
return state;
}
}
export default combineReducers({
authReducer: authReducer
});
authLoading.js // screen
class AuthLoadingScreen extends React.Component {
constructor() {
super();
}
componentDidMount = () => {
this.props.getUserSession().then(() => {
console.log( 'Props at loading: ', this.props.user );
// undefined
})
.catch(error => {
})
};
// Render any loading content that you like here
render() {
return ();
}
}
const mapStateToProps = state => ({
user: state.user,
});
const mapDispatchToProps = dispatch => ({
getUserSession: () => dispatch(getUserSession()),
});
export default connect(mapStateToProps, mapDispatchToProps)(AuthLoadingScreen);
You cannot access directly user of reducer. So change
const mapStateToProps = state => ({
user: state.user,
});
To
const mapStateToProps = state => ({
user: state.authReducer.user,
});
And one more thing AsyncStorage's getItem() method return string of stored data. You have not converted to it json. So please also convert that as below :
export const getUserSession = () => dispatch => {
return AsyncStorage.getItem('userSession').then((data) => {
console.log('Props at asynsstorage: ', data);
// {"current_user":{"uid":"1","roles":["authenticated","administrator"], ...}
dispatch(loading(false));
dispatch(getSession(JSON.parse(data))); //convert to json here
})
.catch((err) => {
})
}