is it possible to simplify the following code further, or is this the cleanest way possible? What I'm trying to do is, if the action.payload is not included in roles array, push it into it, if it is there remove it. I don't want to use lodash for this.
const idx = state.rolesFilter.findIndex(
role => role === action.payload,
);
if (idx === -1) {
nextState.roles.push(action.payload);
} else {
nextState.roles = state.roles.filter(role => role !== action.payload);
}
You could use Set
const set = new Set(state.roles);
const action = set.has(action.payload) ? 'delete' : 'add';
set[action](action.payload);
nextState.roles = [...set];
If you plan on using "toggle" a lot you may create a function
function toggle(array, item) {
const set = new Set(array);
const action = set.has(item) ? 'delete' : 'add';
set[action](item);
return [...set];
}
Related
I am using a JS class, I have following code:
class Field {
public Value = null;
public Items = [];
public UniqueKey = null;
public getItems() {
let items = [...this.Items];
items = items.filter((item) => {
if (item.VisibleIf) {
const matched = item.VisibleIf.match(/\$\[input:(.*?)\]/g);
if (matched?.length) {
const srv = Service.getInstance();
for (let match of matched) {
match = match.slice(8, -1);
if (srv.Fields?.length) {
let found = srv.Fields.find((x) => x.UniqueKey === match);
if (found) {
item.VisibleIf = item.VisibleIf.replace(
`$[input:${match}]`,
found.Value ?? ''
);
return JSON.parse('' + eval(item.VisibleIf));
}
}
}
}
}
return true;
});
return items;
}
public getInputTitle() {
let title = this.Title;
const matched = title.match(/\$\[input:(.*?)\]/g);
if (matched?.length && title) {
const srv = Service.getInstance();
for (let match of matched) {
match = match.slice(8, -1);
if (srv.Fields?.length) {
let found = srv.Fields.find((x) => x.UniqueKey === match);
if (found) {
title = title.replace(`$[input:${match}]`, found.Value ?? '');
}
}
}
}
return title;
}
}
Now I have a Vue component:
<div v-for="Field in Fields" :key="Field.UniqueKey">
<v-select
v-if="Field.Type == 'Select'"
:label="Field.getInputTitle()"
v-model="Field.Value"
:items="Field.getItems()"
item-text="Value"
item-value="Id"
/>
<v-input
v-else-if="Field.Type == 'Input'"
v-model="Field.Value"
:label="Field.getInputTitle()"
/>
</div>
// JS
const srv = Service.getInstance();
Fields = srv.getFields(); // <- API call will be there.
So basically, data comes from an API, having Title as Input $[input:uniqueKey], in a component I am looping over the data and generating the fields. See getInputTitle function in Field class, it works very well. All the fields which are dependent on the $[input:uniqueKey] are changing when I start typing into that field on which other fields are dependent.
Now I have pretty much same concept in the getItems function, so basically, what I want to do is whenever I type into a field and that field exists in the VisibleIf on the Items, the VisibleIf will be like '$[input:uniqueKey] < 1', or any other valid JavaScript expression which can be solved by eval function. But the getItems function is called only 1st time when page gets loaded, on the other hand the getInputTitle function which is pretty much same, gets called every time when I type into the field.
I tried to explain at my best, I will provide any necessary information if needed.
Any solution will be appreciated. Thanks.
You are updating the Object itself in here:
item.VisibleIf = item.VisibleIf.replace( `$[input:${match}]`, found.Value ?? '' );
Even though you tried to copy the array, but you have done shallow copy of the object in here: let items = [...this.Config.Items];
I suggest the following solution:
const visibleIf = item.VisibleIf.replace(
`$[input:${match}]`,
found.Value ?? ''
);
const val = '' + helpers.evalExp('' + visibleIf);
if (helpers.isJSON(val)) {
return JSON.parse(val);
}
Means instead of changing the VisibleIf object, just store it into the variable and just use that.
I hope that it will fix your issue. Let me know if it works.
I have this div that perform an onclick event by increasing the value of an upvote when a user click on the div. It increment which is fine, but I only want it to increment only once even when the user clicks on the div multiple times.
Here is my code
btnUpvote(data) {
let feeds = [...this.state.feeds]
let feed = feeds.find(x => x.id === data.id)
// feed.upvote +1
let get = feed.upvote + 1
console.log(get)
if (feed.upvote !== get) {
}
this.setState({
feeds
})
}
The value of the feed.upvote is stored in an array of object, any help would be appreciated.
Try adding this condition :
let get = 0
if(!feed.upvote){
get= feed.upvote + 1}
You could use an array to store the id which has already been upvoted.
Check it and handle your clicks accordingly.
let allowOneClicks = [];
function allowOnce(id, callback) {
if (allowOneClicks.includes(id)) return;
allowOneClicks.push(id);
callback();
}
In your case, it can be like this.
// outside your component;
const upvotedIds = [];
btnUpvote(data) {
let feeds = [...this.state.feeds]
let feed = feeds.find(x => x.id === data.id)
if (upvotedIds.includes(id)) return;
upvotedIds.push(id);
// upvote here.
}
you can try this.
onHandleClick = (id) => {
this.setState({
feed: {
...this.state.feed,
[id]: (this.state.feed[id] || 0) + 1
}
})
}
movies = [1,2,3,4,5];
watchedMovies = [1,2,3];
const buttonPressed= false;
movies.map(item => buttonPressed === true ? !watchedMovies.includes(item) &&
console.log(item) : console.log(item))
How can I rethink this to use only one "console.log". I have a button in my react app that if I press will hide my watched movies and the "console.log" is actually a "JSX" element with all the logic here so will be hard for me to transform it into a component so I don't reuse code.
Based on your own answer, I think what you actually want is a filter:
let visibleMovies = movies;
if (!buttonPressed) {
visibleMovies = visibleMovies.filter(item => !watchedMovies.includes(item))
}
// ...
visibleMovies.map(item => /*make JSX element*/)
movies.map(item => (buttonPressed === true || !watchedMovies.includes(item)) &&
console.log(item))
I am trying to find index of array using lodash locationbar. but my react console showing some warnings. can be resolve?
let wishListData = wishList.result;
let j = 0; const jMax = wishListData.length;
for (; j < jMax; j++) {
var index = _.findIndex(products.result, function (product) {
return product.id === wishListData[j]['pid']
});
if (index !== -1) {
products.result[index]['isWishList'] = true;
}
}
Iterate over wishList.result with forEach instead of a for loop, and you'll avoid the warning:
wishListData.forEach(({ pid }) => {
const index = _.findIndex(products.result, ({ id }) => id === pid);
if (index !== -1) {
products.result[index].isWishList = true;
}
});
Note that this is a linter warning, not a Javascript error. Your code works, the linter just considers it to be confusing - better to use array methods instead of loops when possible.
Also, feel free to remove the _ library and just use built-in Javascript methods instead, if you want:
wishListData.forEach(({ pid }) => {
const product = products.result.find(({ id }) => id === pid);
if (product) {
product.isWishList = true;
}
});
Or, for an O(N) solution instead of an O(N^2) solution, figure out all pids first, then iterate over the products:
const pids = new Set(wishListData.map(({ pid }) => pid));
products.result.forEach((product) => {
if (pids.has(product.id)) {
product.isWishList = true;
}
});
You can try something like this as well:
Instead of mutating product in products.result[index]['isWishList'] = true;, you should create new object to minimize side-effect.
Also, instead of looping on wishListData, you can create a list of PIDs and just check index. If this list is created outside, you can create list of PIDs outside as well. That will reduce processing it every time
const wishListPID = wishList.result.map((x) => x.pid);
const result = products.result.map((product) => {
const isWishList = wishListPID.indexOf(product.id) !== -1;
return { ...product, isWishList }
});
I am new to react js. I am creating a comparison between user typing and actual sentence to be typed Somehow I am able to achieve this but It is not perfect like nested map is not rendering properly if letter typed correctly it should render green background My state is updated properly But my nested map Kinda not working there is a delay
Component Code
renderLine = () => {
let test = this.props.test.get('master')
return test.map(line => {
return line.check.map( (ltr,i) => ltr.status ? <span key={i} className="correct">{ltr.letter}</span> : ltr.letter )
})
};
handleKeyPress = e => {
if(e.charCode === 32) {
this.setState({
pushToNext:true,
currentTyping:""
})
}
};
handleInput = e => {
if(e.target.value !== " "){
let {storeValue} = this.state;
console.log(storeValue.length);
let updatedWord = e.target.value;
let updateArr = [];
if(storeValue.length === 0){
updateArr = storeValue.concat(updatedWord)
}else {
if(this.state.pushToNext){
updateArr = storeValue.concat(updatedWord)
}else {
storeValue.pop();
updateArr = storeValue.concat(updatedWord);
}
}
this.setState({
currentTyping:updatedWord,
storeValue:updateArr,
pushToNext:false
},() => {
let {storeValue} = this.state
let lastWordIndex = storeValue.length === 0 ? storeValue.length : storeValue.length - 1;
let lastLetterIndex = storeValue[lastWordIndex].length === 0 ? storeValue[lastWordIndex].length : storeValue[lastWordIndex].length - 1;
let lastWordValue = storeValue[lastWordIndex];
let lastLetterValue = lastWordValue[lastLetterIndex];
// console.log(lastWordIndex,lastLetterIndex,lastWordValue,lastLetterValue,"After tstae")
return this.props.compareCurrentTextWithMater(lastWordIndex,lastLetterIndex,lastWordValue,lastLetterValue)
});
}
};
Redux Reducer
import {FETCH_USER_TYPING_TEXT,COMPARE_TEXT_WITH_MASTER} from "../actions/types";
import {fromJS} from 'immutable';
const initialState = fromJS({
text:null,
master:[],
inputBoxStatus:false
});
export default function (state = initialState,action) {
switch (action.type){
case FETCH_USER_TYPING_TEXT:
return setTextManipulated(state,action);
case COMPARE_TEXT_WITH_MASTER:
return compareTextWithMaster(state,action)
default:
return state
}
}
const compareTextWithMaster = (state,action) => {
let {lastWordIndex,lastLetterIndex,lastLetterValue} = action;
let masterWord = state.get('master')[lastWordIndex];
let masterLetter = masterWord.check[lastLetterIndex];
let newState = state.get('master');
if(typeof masterLetter !== "undefined"){
if(masterLetter.letter === lastLetterValue){
masterWord.check[lastLetterIndex].status = true;
newState[lastWordIndex] = masterWord;
return state.set('master',newState)
}else {
masterWord.check[lastLetterIndex].status = false;
newState[lastWordIndex] = masterWord;
return state.set('master',newState)
}
}else {
console.log('Undefinedd Set Eroing or wrong Space Chratced set Box Red Colot',newState);
}
};
UPDATE
I did the same Logic with plain React.js it works Perfectly and nested map rendering the if else logic properly there is no on letter delay
https://codesandbox.io/s/zx3jkxk8o4
But the same logic with Redux State with immutable js Does'nt take effect with nested loop if else statement I don't know where the problem Relies ..and My Code Snippet will be little bit different from CodeSanbox COde But the Logic is Same
Probably, the diffing algorithm of react does see that oldState === newState and skips the re rendering. To avoid that situation, use a new object in the root of the state so that the above check returns false. I see that you use immutableJs, so maybe force re-render with componentShouldUpdate method instead.
Also consider using dev tools to step through the code line by line to see what is going on.
If nothing at all works, switch to something simpler with less dependencies and go from there, incrementally adding what you need.