Actually I need to handle mysite frontend fully with json objects(React and lodash).
I am getting the initial data via an ajax call we say,
starred[] //returns empty array from server
and am adding new json when user clicks on star buton it,
starred.push({'id':10,'starred':1});
if the user clicks again the starred should be 0
current_star=_findWhere(starred,{'id':10});
_.set(curren_star,'starred',0);
but when doing console.log
console.log(starred); //returns
[object{'id':10,'starred':0}]
but actually when it is repeated the global json is not updating,while am performing some other operations the json is like,
console.log(starred); //returns
[object{'id':10,'starred':1}]
How to update the global , i want once i changed the json, it should be changed ever.Should I get any idea of suggesting some better frameworks to handle json much easier.
Thanks before!
The Lodash _. isJSON() method checks whether the given value is a valid JSON or not and returns the corresponding boolean value. Syntax: _.
The Lodash _. isEqual() Method performs a deep comparison between two values to determine if they are equivalent. This method supports comparing arrays, array buffers, boolean, date objects, maps, numbers, objects, regex, sets, strings, symbols, and typed arrays.
get() method in Lodash retrieves the object's value at a specific path. If the value is not present at the object's specific path, it will be resolved as undefined . This method will return the default value if specified in such a case.
Working with arrays is complicated and usually messy. Creating an index with an object is usually much easier. You could try a basic state manager like the following:
// This is your "global" store. Could be in a file called store.js
// lodash/fp not necessary but it's what I always use.
// https://github.com/lodash/lodash/wiki/FP-Guide
import { flow, get, set } from 'lodash/fp'
// Most basic store creator.
function createStore() {
let state = {}
return {
get: path => get(path, state),
set: (path, value) => { state = set(path, value, state) },
}
}
// Create a new store instance. Only once per "app".
export const store = createStore()
// STARRED STATE HANDLERS
// Send it an id and get back the path where starred objects will be placed.
// Objects keyed with numbers can get confusing. Creating a string key.
const starPath = id => ['starred', `s_${id}`]
// Send it an id and fieldId and return back path where object will be placed.
const starField = (id, field) => starPath(id).concat(field)
// import to other files as needed
// Add or replace a star entry.
export const addStar = item => store.set(starPath(item.id), item)
// Get a star entry by id.
export const getStar = flow(starPath, store.get)
// Get all stars. Could wrap in _.values() if you want an array returned.
export const getStars = () => store.get('starred')
// Unstar by id. Sets 'starred' field to 0.
export const unStar = id => store.set(starField(id, 'starred'), 0)
// This could be in a different file.
// import { addStar, getStar, getStars } from './store'
console.log('all stars before any entries added:', getStars()) // => undefined
const newItem = { id: 10, starred: 1 }
addStar(newItem)
const star10a = getStar(10)
console.log('return newItem:', newItem === star10a) // => exact match true
console.log('star 10 after unstar:', star10a) // => { id: 10, starred: 1 }
console.log('all stars after new:', getStars())
// Each request of getStar(10) will return same object until it is edited.
const star10b = getStar(10)
console.log('return same object:', star10a === star10b) // => exact match true
console.log('return same object:', newItem === star10b) // => exact match true
unStar(10)
const star10c = getStar(10)
console.log('new object after mutate:', newItem !== star10c) // => no match true
console.log('star 10 after unstar:', getStar(10)) // => { id: 10, starred: 0 }
console.log('all stars after unstar:', getStars())
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