Ngrx/effects is not working in async with angular 2 - ngrx

Am new to Ngrx, We got stuck with the implementation , Need some help
Architecture:
We are trying to fill the store when the User is authenticated by that time am trying to redirect.
Expectation:
Effects should be called as async and In ui we have to do the redirect
Problem:
Redirection to Homepage is happening only after the ngrx/effect api call is done.
this.userService.authenticateUser(this.userId.toUpperCase(), this.password, (user) => {
this.authenticatedUser = user;
//Call the ngrx dispatchMethod to fill the store
this.router.navigateByUrl("/home");
this.ngrxGetModule_data();
async ngrxGetModule_data() {
this.store.dispatch({ type: Affaire_Action.Affaire_Addstore_Login });
//this.store.dispatch({ type: Affaire_Action.Initial_Store });
}
#Effect()
updateAffaireStore$: Observable<Action> = this.actions$
.ofType(Affaire_Action.Affaire_Addstore_Login)
.map<Action, string>(toPayload)
.switchMap(res => this.affaireService.getAffairesSearchSuggetions('')
//.delay(10000)
.map(res => (
{
type: Affaire_Action.Affaire_on_Success, payload: ({ "parameter": SearchSuggestion, "data": res })
}
)))
.catch(error => Observable.of({ type: Affaire_Action.Affaire_on_Failure, payload: null }))

What are you actually trying with the this.userService.authenticateUser ?
Seems like you are trying to call the function but the way you are doing is wrong.
What is the return type?!!! Observable or promise.
Suggestion: You should call services on you effect and dispatch actions from effect. You can also use this.router.navigateByUrl("/home"); on your effect.

Related

How to reduce Waiting TTFB time on GET request to database?

I am having problems with my Axios GET requests taking up to 3-7 seconds to retrieve the data from my Firebase Cloud Firestore Database. I have tried searching up page optimization techniques to speed up my page load such as cacheing resources or image optimization but nothing is helping with the actual request time. The image below is for 1 GET request which pulls an array of objects from the database. It's not as if it's a large array though, there is only 6 objects currently in it and it still takes very long to retrieve. This happens for all of my get requests and I'm not sure why.
It isn't only on initial page load, it still takes a couple seconds (generally 2-5 on subsequent loads) to load in even after refreshing the page or moving between pages on my site. It's not consistent at all and I was wondering if there was anything I can do to improve the request speed.
The Action for the "posts" request above. I am using React Redux to get the json data from Firebase Database and adding it to my store:
// get all posts
export const getPosts = () => (dispatch) => {
dispatch({ type: LOADING_DATA });
axios
.get("/posts")
.then((res) => {
dispatch({
type: SET_POSTS,
payload: res.data,
});
})
.catch(() => {
dispatch({
type: SET_POSTS,
payload: [],
});
});
};
The reducer:
export default function (state = initialState, action) {
switch (action.type) {
case SET_POSTS:
return {
...state,
posts: action.payload,
loading: false,
};
default:
return state;
}
}
Firebase functions:
// fetch all posts
exports.getAllPosts = (req, res) => {
db.collection("posts")
.orderBy("createdAt", "desc")
.get()
.then(data => {
let posts = [];
data.forEach(doc => {
posts.push({
postId: doc.id,
body: doc.data().body,
userHandle: doc.data().userHandle,
createdAt: doc.data().createdAt,
commentCount: doc.data().commentCount,
likeCount: doc.data().likeCount,
userImage: doc.data().userImage
});
});
return res.json(posts);
})
.catch(err => console.error(err));
};
Another example of my GET request to retrieve user data after login:

Api middleware with redux-observable

I'm refactoring my react/redux app to use redux-observable instead of redux-thunk. Using thunk, I have an api middleware set up to listen for any actions with a CALL_API key and do some manipulation of the data, prepare headers, prepare full url, perform an api call using axios, and also do some additional action dispatches related to an api call.
Importantly, the api middleware dispatches a REQUEST_START action which gives the request an id and sets its status to pending in the network part of my state. When the promise from axios resolves or rejects, the middleware dispatches a REQUEST_END action, updating the state so that the current request is set to resolved or rejected. Then the response is returned to the calling action creator that initially dispatched the CALL_API action.
I have not been able to figure out how to do this with redux-observable. The part about the api middleware described above that I want to replicate is the REQUEST_START and REQUEST_END action dispatches. It's very convenient to have a centralized place where all api call related stuff is handled. I know I can effectively dispatch the REQUEST_START and REQUEST_END actions in each of my epics that does an api call, but I don't want to have to repeat the same code in many places.
I managed to partially solve this by creating an apiCallEpic which listens for actions with type CALL_API and does the above setup for api calls. However, an issue (or rather, something I don't like) is that the epic that initiates the api call (e.g. getCurrentUserEpic) essentially gives up control to apiCallEpic.
So, for example, when the api call succeeds and has a response, I may want to format that response data in some way before dispatching an action to be handled by my reducer. That is, getCurrentUserEpic should do some formatting of data returned from api call before sending to reducer. I was able to achieve something close to this by passing a payloadHandler callback function defined in getCurrentUserEpic that the apiCallEpic can call if/when it gets a successful response. However, I don't like this callback architecture and it seems like there's got to be a better way.
Here is some code that demonstrates my use of api middleware using thunk.
import axios from 'axios';
// actionCreators.js
// action types
const CALL_API = "CALL_API";
const FETCH_CURRENT_USER = "FETCH_CURRENT_USER";
const RECEIVE_CURRENT_USER = "RECEIVE_CURRENT_USER";
// action creators for request start and end
export const reqStart = (params = {}) => (dispatch) => {
const reduxAction = {
type: REQ_START,
status: 'pending',
statusCode: null,
requestId: params.requestId,
}
dispatch(reduxAction);
}
export const reqEnd = (params = {}) => (dispatch) => {
const {
requestId,
response = null,
error = null,
} = params;
let reduxAction = {}
if (response) {
reduxAction = {
type: REQ_END,
status: 'success',
statusCode: response.status,
requestId,
}
}
else if (error) {
if (error.response) {
reduxAction = {
type: REQ_END,
status: 'failed',
statusCode: error.response.status,
requestId,
}
}
else {
reduxAction = {
type: REQ_END,
status: 'failed',
statusCode: 500,
requestId,
}
}
}
dispatch(reduxAction);
}
// some api call to fetch data
export const fetchCurrentUser = (params = {}) => (dispatch) => {
const config = {
url: '/current_user',
method: 'get',
}
const apiCall = {
[CALL_API]: {
config,
requestId: FETCH_CURRENT_USER,
}
}
return dispatch(apiCall)
.then(response => {
dispatch({
type: RECEIVE_CURRENT_USER,
payload: {response},
})
return Promise.resolve({response});
})
.catch(error => {
return Promise.reject({error});
})
}
// apiMiddleware.js
// api endpoint
const API_ENTRY = "https://my-api.com";
// utility functions for request preparation
export const makeFullUrl = (params) => {
// ...prepend endpoint url with API_ENTRY constant
return fullUrl
}
export const makeHeaders = (params) => {
// ...add auth token to headers, etc.
return headers;
}
export default store => next => action => {
const call = action[CALL_API];
if (call === undefined) {
return next(action);
}
const requestId = call.requestId;
store.dispatch(reqStart({requestId}));
const config = {
...call.config,
url: makeFullUrl(call.config),
headers: makeHeaders(call.config);
}
return axios(config)
.then(response => {
store.dispatch(reqEnd({
response,
requestId,
}))
return Promise.resolve(response);
})
.catch(error => {
store.dispatch(reqEnd({
error,
requestId,
}))
return Promise.reject(error);
})
}
// reducers.js
// Not included, but you can imagine reducers handle the
// above defined action types and update the state
// accordingly. Most usefully, components can always
// subscribe to specific api calls and check the request
// status. Showing loading indicators is one
// use case.
Here's the code I've implemented to accomplish a similar thing with redux-observable.
export const fetchCurrentUserEpic = (action$, state$) => {
const requestType = FETCH_CURRENT_USER;
const successType = RECEIVE_CURRENT_USER;
const requestConfig = {
url: "/current_user",
method: "get",
}
const payload = {requestConfig, requestType, successType};
const payloadNormalizer = ({response}) => {
return {currentUser: response.data.data};
}
return action$.ofType(FETCH_CURRENT_USER).pipe(
switchMap((action) => of({
type: CALL_API,
payload: {...payload, requestId: action.requestId, shouldFail: action.shouldFail, payloadNormalizer},
})),
)
}
export const apiEpic = (action$, state$) => {
return action$.ofType(CALL_API).pipe(
mergeMap((action) => (
concat(
of({type: REQ_START, payload: {requestId: action.payload.requestId, requestType: action.payload.requestType}}),
from(callApi(action.payload.requestConfig, action.payload.shouldFail)).pipe(
map(response => {
return {
type: action.payload.successType,
payload: action.payload.payloadNormalizer({response})
}
}),
map(() => {
return {
type: REQ_END,
payload: {status: 'success', requestId: action.payload.requestId, requestType: action.payload.requestType},
}
})
)
)
).pipe(
catchError(error => {
console.log('error', error);
return of({type: REQ_END, payload: {status: 'failed', requestId: action.payload.requestId, requestType: action.payload.requestType}, error});
})
)
)
)
}
Any comments or suggestions are appreciated!
I've found redux-fetch-epic-builder (A lib for building "fetch actions" and generic epics handled by redux-observable) to be similar to what you are trying to achieve here (beware it uses rxjs 5, this guide to rescue). It uses fetch, not axios, but it's easy to replace that. Plus it has transformers for successful/failed actions.
The library is a bit old, but the base idea to overcome boilerplate code is still valid: Generic epic-builder to fetch data with calls to API(s).
I am a novice in React / Redux / RxJS, but the only problem I see with the redux-fetch-epic-builder is the way to configure the client (in axios terms). That is, I am not fully satisfied with (due to it being not FSA or RSAA):
//action creators
const getComments = (id, page = 1) => ({
type: GET_COMMENTS,
host: 'http://myblog.com',
path: `/posts/${id}/comments`,
query: {
page,
},
})
// ...
const epics = [
buildEpic(GET_COMMENTS),
]
but this may still be an elegant way. And the license allow to develop the library further. I have not converted the example from the library documentation to your user-related example, but with react-observable there is certainly no need to introduce a separate "api middleware". (Also, I like /SUBACTION better than _SUBACTION, but it's trivial to change.)

Share actions between domains

Usually I use redux-saga, but currently I need redux-thunk. I'm using ducks for modular structure and now for example I have two ducks: auth and user with async actions below:
auth-duck.js
register(credentials) {
return dispatch => {
dispatch(actions.registerRequest());
return service.requestRegister(credentials)
.then((response) => {
dispatch(actions.registerSuccess(...));
// Here I need to dispatch some action from user-duck.js
})
.catch(() => dispatch(actions.registerError(...)))
}
}
user-duck.js
fetchUser() {
return dispatch => {...}
}
I really don't know how to not mess these two modules and dispatch fetchUser after successful register.
I could return register result (e.g. token or something else) to container from here it was dispatched and then using chaining dispatch fetchUser.
AuthContainer.js
_onSubmit() {
this.props.register().then(() => this.props.fetchUser);
}
But I don't know is it the best way to manage such operations with redux-thunk?
There is no rule thunks can only make one HTTP request. If you need to fetch the user after login, then fetch it.
const login = credentials => dispatch => {
fetchLogin(credentials).then(() => {
dispatch({ type: "LoginSuccess" })
return fetchUser()
}).then(() => {
dispatch({ type: "UserFetched" })
})
}
If you want to reuse the user fetch action, then dispatch a thunk from a thunk.
const fetchCurrentUser = login => dispatch => {
return fetchUser(login.userId).then(user => {
dispatch({ type: "UserLoad" })
return user
})
}
const login = credentials => dispatch => {
return fetchLogin(credentials).then(login => {
dispatch({ type: "LoginSuccess" })
return dispatch(fetchCurrentUser(login))
}
}
In one of my apps, I call 7 action thunks after successful login.
After a long search I found two options how to share the logic from separate domains.
The first one is to use mapDispatchToProps (Thanks #DonovanM), just like this:
function mapDispatchToProps(dispatch) {
return {
login: (credentials) => {
return dispatch(authActions.login(credentials)).then(
() => dispatch(userActions.fetchUser())
);
}
}
}
login function returns Promise thats why we can chain it to another one.
And the second possible option:
Use something like a "bridge" file in our case it is app-sagas.js
app-duck.js
import {actions as authActions} from './auth-duck.js';
import {actions as userActions} from './user-duck.js';
export function doLogin(credentials) {
return dispatch => {
return dispatch(authAction.login(credentials)).then(
() => dispatch(userActions.fetchUser())
);
}
}
In the second case we can place all logic into ducks and avoid spreading the logic within containers. But I guess it is possible to combine both methods.

Ngrx: populate success dispatched actions on component

I'm dispatching an ADD_SOURCE action from my component that when it success dispatches another ADD_SOURCE_SUCCESS:
this.store$
.select(fromRoot.getUserState)
.filter(user => user.id != null && user.logged)
.takeUntil(this.componentDestroyed$)
.do(user => this.store$.dispatch({type: 'ADD_SOURCE', payload: user.username}))
.subscribe();
This is the effect that returns the ADD_SOURCE_SUCCESS according to a net call:
#Effect({ dispatch: true })
addSource$: Observable<Action> = this.actions$
.ofType('ADD_SOURCE')
.switchMap(
(action: Action) =>
this.userService.addCard(action.payload.username, action.payload.token)
.map((card: CardDTO) => {
return <Action>{
type: 'ADD_SOURCE_SUCCESS',
payload: <ICard>{ ... }
};
})
.catch(_ => {
return Observable.of(<Action>{ type: 'ADD_SOURCE_FAILED', payload: { }});
}));
So, then a new ADD_SOURCE_SUCCESS is dispatched on my reducer:
private static saveSourceSuccess(sourcesRdx, type, payload) {
return <ISourceRedux>{
ids: [ ...sourcesRdx.ids, payload.id ],
entities: Object.assign({}, sourcesRdx.entities, {[payload.id]: payload}),
selectedIds: sourcesRdx.selectedIds,
editingSource: null
};
}
Nevertheless, I don't quite figure out how to say on my component that the operation has been success and do one thing or another one...
Any ideas?
in your reducer, you should also handle the success & fail errors, set the store with an error message or whatever you need as data, and make a selector on it. Then the ui should subscribe to this new selector and you ll be notified
check this chapter
selectors

Why does redux-mock-store don't show an action dispatched in catch promises?

I'm very bad when it comes to thinking of a title question, sorry for that.
My Problem:
I'm unit testing my async redux actions like it's suggested in the docs. I mock the API calls with nock and check for the dispatched actions with redux-mock-store. It works great so far, but I have one test that fails even though it clearly does work. The dispatched action neither does show up in the array returned by store.getActions() nor is the state changed in store.getState(). I'm sure that it does happen because I can see it when I test manually and observe it with Redux Dev Tools.
The only thing that is different in this action dispatch is that it is called in a promise in a catch of another promise. (I know that sounds confusing, just look at the code!)
What my code looks like:
The action:
export const login = (email, password) => {
return dispatch => {
dispatch(requestSession());
return httpPost(sessionUrl, {
session: {
email,
password
}
})
.then(data => {
dispatch(setUser(data.user));
dispatch(push('/admin'));
})
.catch(error => {
error.response.json()
.then(data => {
dispatch(setError(data.error))
})
});
};
}
This httpPost method is just a wrapper around fetch that throws if the status code is not in the 200-299 range and already parses the json to an object if it doesn't fail. I can add it here if it seems relevant, but I don't want to make this longer then it already is.
The action that doesn't show up is dispatch(setError(data.error)).
The test:
it('should create a SET_SESSION_ERROR action', () => {
nock(/example\.com/)
.post(sessionPath, {
session: {
email: fakeUser.email,
password: ''
}
})
.reply(422, {
error: "Invalid email or password"
})
const store = mockStore({
session: {
isFetching: false,
user: null,
error: null
}
});
return store.dispatch(actions.login(
fakeUser.email,
""))
.then(() => {
expect(store.getActions()).toInclude({
type: 'SET_SESSION_ERROR',
error: 'Invalid email or password'
})
})
});
Thanks for even reading.
Edit:
The setErroraction:
const setError = (error) => ({
type: 'SET_SESSION_ERROR',
error,
});
The httpPostmethod:
export const httpPost = (url, data) => (
fetch(url, {
method: 'POST',
headers: createHeaders(),
body: JSON.stringify(data),
})
.then(checkStatus)
.then(response => response.json())
);
const checkStatus = (response) => {
if (response.status >= 200 && response.status < 300) {
return response;
}
const error = new Error(response.statusText);
error.response = response;
throw error;
};
Because of you are using nested async function in catch method - you need to return the promise:
.catch(error => {
return error.response.json()
.then(data => {
dispatch(setError(data.error))
})
});
Otherwise, dispatch will be called after your assertion.
See primitive examples:
https://jsfiddle.net/d5fynntw/ - Without returning
https://jsfiddle.net/9b1z73xs/ - With returning

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