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Accessing other parts of the state, when using combined reducers
(4 answers)
Closed 4 years ago.
I'm starting with React-Native and Redux. I'm using combineReducers to make my reducer live easy, passing just the element that I need (from 'global' state).
This is my idea of state and my code for combineReducers:
State:
{
race: [ {...}, {...}, {...}],
pilots: [ {...}, {...}, {...}],
<other stuff>
}
Code:
const rootReducer = combineReducers({
race: addLapReducer,
pilots: editingPilotsReducer
});
const store = createStore(rootReducer, devToolsEnhancer());
This is working fine as expected. The only problem is that I need to access 'pilots' array from 'addLapReducer'. Is this possible? If yes, how?
I know that if I create my store with only one reducer (instead of combineReducer), the full state will be sent to my reducer......but is not the case here.
One thing that I tought if using both: combinedReducers and 'standard' reducer, but I don't know how to do this.
The only problem is that I need to access 'pilots' array from 'addLapReducer'
I believe a better place to access the pilots array is from the action creator in which you return an action with a type handled by addLapReducer.
Say for example you have an action creator that looks like this:
function somethingLaps() {
return {type: ADD_LAPS, payload: 1}
}
You can change that to return a function with the dispatch argument as well as getState, in order to access the pilots array:
function somethingLaps() {
return (dispatch, getState) => {
dispatch({type: ADD_LAPS, payload: 1})
let {pilots} = getState()
// I'm making up what you might have needed pilots array for
// add a new pilot
let newPilots = pilots.concat([{
name: 'Chesley Sullenberger',
nickname: 'Sully'
}])
dispatch({type: UPDATE_PILOTS, payload: newPilots})
}
}
Related
OK, say I have an initial state in our Redux store that looks like this:
const initialState = {
userReports: [],
activeReport: null,
}
userReports is a list of reports. activeReport is one of those reports (the one that is actively being worked with).
I want the active report to point to one in the array. In other words, if I modify the active report, it would modify one in the userReports array. This means, the two objects must point to the same memory space. That's easy to set up.
The alternative to this approach would be to copy one of the reports that is in the userReports array and set it as the active report (now it has a different memory address). The problem is now, when I edit the activeReport, I also have to search through the array of userReports, find the report that resembles the active report and modify it there too. This feels verbose.
Here is the question:
Would it be bad practice to have the activeReport point to a report in the array (same object). When I want to change the report I could do something like this (example is using redux thunk):
export const updateReport = (report) => async (dispatch, getState) => {
try {
const report = getState().reports.activeReport
// modify the active report here
report.title = "blah blah blah"
dispatch({ type: ACTIONS.UPDATE_REPORT, payload: report })
} catch (error) {
console.log(`ERROR: ${error.message}`)
}
}
And in my reducer:
case ACTIONS.UPDATE_REPORT:
return { ...state, activeReport: action.payload }
as you can see, after updating the report I still return a "new version" of that report and set it as active, but this approach also updates the report in the userReports array because they point to the same memory address.
I would say thats not ideal, do the reports have id's? If they do I would rather hold the userReports in an object with keys being the id's, then active report can just be an id and renamed to activeReportId so you can fetch the activeReport with userReports[activeReportId]
You also asked for reasons:
So firstly any screen that looks at userReports wont rerender because the reports aren't being reassigned.
Secondly if someone later wants to update those screens they will reassign userReports which could cause problems.
Thirdly its an unusual pattern which is a huge no no for redux. The point of redux is that it has a very obvious pattern so when you add things to it you don't have to think and can just make changes with confidence.
Your activeReport should not be pointing to an object in the userReports array, but rather it should be an id of the report, which the user is currently working on. Each of the report in the userReports will have a unique id field to identify the report - this would be helpful when rendering in react - this id field can be used as key.
Then your action creator/dispatcher will look like this:
export const updateReport = (updatedReport) => async (dispatch, getState) => {
dispatch({ type: ACTIONS.UPDATE_REPORT, payload: updatedReport });
}
You will call this on change in your component:
const onTitleChangeHandler = (e) => {
var newTitle = e.target.value;
// you will get the userReports and activeReport from props or by using some redux selector, also you will need to get dispatch and getState from redux
var activeReportObj = userReports.filter((r) => r.id === activeReport)[0];
updateReport({ title: newTitle, ...activeReportObj })(dispatch, getState);
}
Lastly, your reducer will be:
case ACTIONS.UPDATE_REPORT:
var newUserReports = state.userReports.map((r) => {
if (r.id === state.activeReport) {
return action.payload;
}
return r;
});
return { newUserReports, ...state };
I am working with Nuxt and Vue, with MySQL database, all of which are new to me. I am transitioning out of WebMatrix, where I had a single Admin page for multiple tables, with dropdowns for selecting a particular option. On this page, I could elect to add, edit or delete the selected option, say a composer or music piece. Here is some code for just 2 of the tables (gets a runtime error of module build failed):
<script>
export default {
async asyncData(context) {
let [{arrangers}, {composers}] = await Promise.all([
context.$axios.get(`/api/arrangers`),
context.$axios.get(`/api/composers`),
])
const {arrangers} = await context.$axios.get('/api/arrangers')
const {composers} = await context.$axios.get('/api/composers')
return { arrangers, composers }
},
}
</script>
You do have the same variable name for both the input (left part of Promise.all) and as the result from your axios call, to avoid naming collision, you can rename the result and return this:
const { arrangers: fetchedArrangers } = await context.$axios.get('/api/arrangers')
const { composers: fetchedComposers } = await context.$axios.get('/api/composers')
return { fetchedArrangers, fetchedComposers }
EDIT, this is how I'd write it
async asyncData({ $axios }) {
const [posts, comments] = await Promise.all([
$axios.$get('https://jsonplaceholder.typicode.com/posts'),
$axios.$get('https://jsonplaceholder.typicode.com/comments'),
])
console.log('posts', posts)
console.log('comments', comments)
return { posts, comments }
},
When you destructure at the end of the result of a Promise.all, you need to destructure depending of the result that you'll get from the API. Usually, you do have data, so { arrangers } or { composers } will usually not work. Of course, it depends of your own API and if you return this type of data.
Since destructuring 2 data is not doable, it's better to simply use array destructuring. This way, it will return the object with a data array inside of it.
To directly have access to the data, you can use the $get shortcut, which comes handy in our case. Directly destructuring $axios is a nice to have too, will remove the dispensable context.
In my example, I've used JSONplaceholder to have a classic API behavior (especially the data part) but it can work like this with any API.
Here is the end result.
Also, this is what happens if you simply use this.$axios.get: you will have the famous data that you will need to access to later on (.data) at some point to only use the useful part of the API's response. That's why I do love the $get shortcut, goes to the point faster.
PS: all of this is possible because Promise.all preserve the order of the calls: https://stackoverflow.com/a/28066851/8816585
EDIT2: an example on how to make it more flexible could be
async asyncData({ $axios }) {
const urlEndpointsToFetchFrom = ['comments', 'photos', 'albums', 'todos', 'posts']
const allResponses = await Promise.all(
urlEndpointsToFetchFrom.map((url) => $axios.$get(`https://jsonplaceholder.typicode.com/${url}`)),
)
const [comments, photos, albums, todos, posts] = allResponses
return { comments, photos, albums, todos, posts }
},
Of course, preserving the order in the array destructuring is important. It's maybe doable in a dynamic way but I don't know how tbh.
Also, I cannot recommend enough to also try the fetch() hook alternative someday. I found it more flexible and it does have a nice $fetchState.pending helper, more here: https://nuxtjs.org/blog/understanding-how-fetch-works-in-nuxt-2-12/ and in the article on the bottom of the page.
In the app I'm creating I have a base store for objects that might be used across the entire app, such as the logged in user, validation errors and the like.
I also have other namespaced modules for specific sections of my app.
When my parent component is loaded there is an ajax call that pulls in data and commits it to the various stores.
export const instantiate = ({ commit, dispatch }) => {
return axios.get('/setup/fetch')
.then((response) => {
dispatch('base/setLoggedInUser', response.data.user, { root: true })
commit('setFetishesList', response.data.fetishes)
commit('setColorsList', response.data.colors)
commit('setRolesList', response.data.roles)
commit('setGendersList', response.data.genders)
commit('setOrientationsList', response.data.orientations)
commit('setLookingsList', response.data.lookings)
commit('setSeekingsList', response.data.seekings)
commit('setBodiesList', response.data.bodies)
commit('setHeightsList', response.data.heights)
commit('setEthnicitiesList', response.data.ethnicities)
commit('setHairsList', response.data.hairs)
commit('setEyesList', response.data.eyes)
commit('setPiercingsList', response.data.piercings)
commit('setTattoosList', response.data.tattoos)
commit('setSmokingsList', response.data.smokings)
commit('setDrinkingsList', response.data.drinkings)
commit('setStatusesList', response.data.statuses)
commit('setEducationsList', response.data.educations)
commit('setAgesList', response.data.ages)
return Promise.resolve(response)
})
}
Then I use mapped getters to access items from my stores.
computed: {
...mapGetters({
user: 'base/getUser',
fetishList: 'setup/getFetishesList',
localeData: 'setup/getLocale',
colorsList: 'setup/getColorsList',
rolesList: 'setup/getRolesList',
genderList: 'setup/getGendersList',
orientationList: 'setup/getOrientationsList',
lookingList: 'setup/getLookingsList',
seekingList: 'setup/getSeekingsList',
validation: 'base/getValidationErrors',
}),
}
All is working as expected except for my user object.
In my Vue inspector I can see that the user object is stored properly in Vuex as expected, but when I console.log(this.user) I get null and anytime I try to access a user property I get console errors.
Can anyone explain why this might be happening, I've never seen this before and have no idea what I'm looking for?
Thanks.
My guess is that your dispatch() (Vue.js actions are ALWAYS expected to be async) is not completing properly. This is how I would rewrite it with a single caveat:
Your base/setLoggedInUser Vuex action MUST return a Promise for this to work properly.
/*
export const instantiate = ({ commit, dispatch }) => {
return axios.get('/setup/fetch')
.then((response) => {
dispatch('base/setLoggedInUser', response.data.user, { root: true })
commit('setFetishesList', response.data.fetishes)
commit('setColorsList', response.data.colors)
commit('setRolesList', response.data.roles)
commit('setGendersList', response.data.genders)
commit('setOrientationsList', response.data.orientations)
commit('setLookingsList', response.data.lookings)
commit('setSeekingsList', response.data.seekings)
commit('setBodiesList', response.data.bodies)
commit('setHeightsList', response.data.heights)
commit('setEthnicitiesList', response.data.ethnicities)
commit('setHairsList', response.data.hairs)
commit('setEyesList', response.data.eyes)
commit('setPiercingsList', response.data.piercings)
commit('setTattoosList', response.data.tattoos)
commit('setSmokingsList', response.data.smokings)
commit('setDrinkingsList', response.data.drinkings)
commit('setStatusesList', response.data.statuses)
commit('setEducationsList', response.data.educations)
commit('setAgesList', response.data.ages)
return Promise.resolve(response)
})
}
*/
export const instantiate = ({ commit, dispatch }) => {
return axios.get('/setup/fetch')
.then((response) => Promise.all([
dispatch('base/setLoggedInUser', response.data.user, { root: true }),
Promise.resolve(response)
]))
.then(([dispatchResponse, response]) => {
commit('setFetishesList', response.data.fetishes)
commit('setColorsList', response.data.colors)
commit('setRolesList', response.data.roles)
commit('setGendersList', response.data.genders)
commit('setOrientationsList', response.data.orientations)
commit('setLookingsList', response.data.lookings)
commit('setSeekingsList', response.data.seekings)
commit('setBodiesList', response.data.bodies)
commit('setHeightsList', response.data.heights)
commit('setEthnicitiesList', response.data.ethnicities)
commit('setHairsList', response.data.hairs)
commit('setEyesList', response.data.eyes)
commit('setPiercingsList', response.data.piercings)
commit('setTattoosList', response.data.tattoos)
commit('setSmokingsList', response.data.smokings)
commit('setDrinkingsList', response.data.drinkings)
commit('setStatusesList', response.data.statuses)
commit('setEducationsList', response.data.educations)
commit('setAgesList', response.data.ages)
return Promise.resolve(response)
})
}
There are two main posibilities here:
The first one is that you might not be defining properly the user getter.
The second one, console.log is being executed previous to the data being set by this action:
dispatch('base/setLoggedInUser', response.data.user, { root: true })
Vuex actions are asynchronous, so setLoggedInUser could have started before the console.log (and the code giving you errors) is executed, but the actual data might not have been received yet at that point (it would be undefined).
If this is the case, add the following condition to the part of the template or the component(s) that are using the block of code where you are getting those errors:
v-if="user"
This will make Vue to wait for the mapped getter user to have a value to mount said template segment or components, avoiding trying to access properties of undefined.
I am trying to update an array inside of my array (nested array) with react-redux. I found a solution to how to do this but is there any easier way of doing this rather than passing multiple parameter to the action.
[types.HISTORY_UPDATE](state, action){
return {
...state,
budgets: [
...state.budgets.slice(0,action.id),
{
key: action.key,
id: action.idd,
name: action.name,
budgetType: action.budgetType,
startDate: action.startDate,
currency: action.currency,
amount: action.amount,
amountLeft: action.amountLeft,
rollOver: action.rollOver,
color: action.color,
iconName: action.iconName,
history: [
...state.budgets[action.id].history.slice(0,action.histId),
{
note: action.note,
amount: action.amount,
type: action.type,
date: action.date,
fullDate: action.fullDate,
hours: action.hours,
min: action.min,
month: action.month,
year: action.year
},
...state.budgets[action.id].history.slice(action.histId+1)
]
},
...state.budgets.slice(action.id+1)
]
}
},
and the action goes like this
export function updateHistory(id,key,idd,name,budgetType,startDate,currency,amount,amountLeft,rollOver,color,iconName,histId,........){
I don't want to spend time with passing multiple parameter like this while using react-redux and also while I tried to run my application on my phone sometimes it really slows the application. Is it because of the example above?
I would be really appreciated If you guys come up with a solution.
I typically do not store arrays in redux, since updating a single element really is a burden as you noticed. If the objects you have inside your array all have a unique id, you can easily convert that array to an object of objects. As key for each object you take that id.
const convertToObject = (array) => {
let items = {};
array.map((item) => {
items[item.id] = item;
});
return items;
};
In your action you simply just pass the item you want to update as payload, and you can update the redux store very easily. In this example below I am just updating the budgets object, but the same logic applies when you assign a history object to each budget.
[types.BUDGET_UPDATE](state, action){
const item = action.payload;
return {
...state,
budgets: {
...state.budgets,
[item.id]: item
}
}
}
And if you want an array somewhere in your component code, you just convert the redux store object back to an array:
const array = Object.values(someReduxStoreObject);
Problem: ignore some part of the .snap file test results
the question here: there are some components in my test that have a random values and i don't really care about testing them. is there any way to ignore part of my X.snap file? so when i run tests in the future it won't give me test fail results.
Now you can also use property matcher for these cases.
By example to be able to use snapshot with these object :
const obj = {
id: dynamic(),
foo: 'bar',
other: 'value',
val: 1,
};
You can use :
expect(obj).toMatchSnapshot({
id: expect.any(String),
});
Jest will just check that id is a String and will process the other fields in the snapshot as usual.
Actually, you need to mock the moving parts.
As stated in jest docs:
Your tests should be deterministic. That is, running the same tests multiple times on a component that has not changed should produce the same results every time. You're responsible for making sure your generated snapshots do not include platform specific or other non-deterministic data.
If it's something related to time, you could use
Date.now = jest.fn(() => 1482363367071);
I know it's quite old question but I know one more solution. You can modify property you want to ignore, so it will be always constant instead of random / dynamic. This is best for cases when you are using third party code and thus may not be able to control the non deterministic property generation
Example:
import React from 'react';
import Enzyme, { shallow } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
import Card from './Card';
import toJSON from 'enzyme-to-json';
Enzyme.configure({ adapter: new Adapter() });
describe('<Card />', () => {
it('renders <Card /> component', () => {
const card = shallow(
<Card
baseChance={1}
name={`test name`}
description={`long description`}
imageURL={'https://d2ph5fj80uercy.cloudfront.net/03/cat1425.jpg'}
id={0}
canBeIgnored={false}
isPassive={false}
/>
);
const snapshot = toJSON(card);
// for some reason snapshot.node.props.style.backgroundColor = "#cfc5f6"
// does not work, seems the prop is being set later
Object.defineProperty(snapshot.node.props.style, 'backgroundColor', { value: "#cfc5f6", writable: false });
// second expect statement is enaugh but this is the prop we care about:
expect(snapshot.node.props.style.backgroundColor).toBe("#cfc5f6");
expect(snapshot).toMatchSnapshot();
});
});
You can ignore some parts in the snapshot tests replacing the properties in the HTML. Using jest with testing-library, it would look something like this:
it('should match snapshot', async () => {
expect(removeUnstableHtmlProperties(await screen.findByTestId('main-container'))).toMatchSnapshot();
});
function removeUnstableHtmlProperties(htmlElement: HTMLElement) {
const domHTML = prettyDOM(htmlElement, Infinity);
if (!domHTML) return undefined;
return domHTML.replace(/id(.*)"(.*)"/g, '');
}
I used this to override moment's fromNow to make my snapshots deterministic:
import moment, {Moment} from "moment";
moment.fn.fromNow = jest.fn(function (this: Moment) {
const withoutSuffix = false;
return this.from(moment("2023-01-12T20:14:00"), withoutSuffix);
});