What is the best way to modify items in localStorage?

Question

What is the best way to modify items in localStorage?

I'm currently facing an issue where the cached object is not reflecting the correct data. It seems like updating the most recent version to the browser cache might help solve this problem.

Could you please provide guidance on how to update localStorage with a new object? For example, if I have a controller with an assessment that has been updated, how can I push that new assessment object up to the localStorage?

javascript angularjs local-storage local

Answer 1

Answer №1

If you wanted to achieve the same result using vanilla JavaScript, you could follow these steps:

localStorage.setItem('itemKey', JSON.stringify(yourObject));
var item = JSON.parse(localStorage.getItem('itemKey'));

When working within an Angular environment, it is recommended to create a localStorage service to serve as a wrapper for localStorage. This service can then be injected into your controller or service. Alternatively, you can inject $window and access localStorage directly like so: $window.localStorage

Answer 2

If you wanted to achieve the same result using vanilla JavaScript, you could follow these steps:

localStorage.setItem('itemKey', JSON.stringify(yourObject));
var item = JSON.parse(localStorage.getItem('itemKey'));

When working within an Angular environment, it is recommended to create a localStorage service to serve as a wrapper for localStorage. This service can then be injected into your controller or service. Alternatively, you can inject $window and access localStorage directly like so: $window.localStorage

Answer 3

Answer №2

Here is a tailored response for the original poster of this similar inquiry:

When working with LocalStorage, keep in mind that it can only store strings. This is why you need to stringify your object before storing it. To manipulate the stored string as an object, utilize `JSON.parse` (as long as it's valid JSON). And when saving the modified version back into LocalStorage, remember to convert it back to a string.

// Create a JSON-formatted object, stringify it, and store it as "ship"
const ship = { name: "Black Pearl", captain: "Jack Sparrow" };
const originalStringifiedForStorage = JSON.stringify(ship);
localStorage.setItem("ship", JSON.stringify(ship));

// Retrieve the string from LocalStorage, parse it into a JavaScript object
const retrievedString = localStorage.getItem("ship");
const parsedObject = JSON.parse(retrievedString);

// Modify the object, stringify it, and update the existing 'ship' in LocalStorage
parsedObject.name = "New Name";
const modifiedAndStringifiedForStorage = JSON.stringify(parsedObject);
localStorage.setItem("ship", modifiedAndStringifiedForStorage);

Answer 4

Here is a tailored response for the original poster of this similar inquiry:

When working with LocalStorage, keep in mind that it can only store strings. This is why you need to stringify your object before storing it. To manipulate the stored string as an object, utilize `JSON.parse` (as long as it's valid JSON). And when saving the modified version back into LocalStorage, remember to convert it back to a string.

// Create a JSON-formatted object, stringify it, and store it as "ship"
const ship = { name: "Black Pearl", captain: "Jack Sparrow" };
const originalStringifiedForStorage = JSON.stringify(ship);
localStorage.setItem("ship", JSON.stringify(ship));

// Retrieve the string from LocalStorage, parse it into a JavaScript object
const retrievedString = localStorage.getItem("ship");
const parsedObject = JSON.parse(retrievedString);

// Modify the object, stringify it, and update the existing 'ship' in LocalStorage
parsedObject.name = "New Name";
const modifiedAndStringifiedForStorage = JSON.stringify(parsedObject);
localStorage.setItem("ship", modifiedAndStringifiedForStorage);

Answer 5

Answer №3

If the data is structured in JSON form (it's unclear if Angular utilizes a different structure), you may be able to utilize the setItem() and getItem() functions for updating and retrieving items from local storage!

Here is an example referenced from the following article:

var me = {name:'myname',age:99,gender:'myGender'};
localStorage.setItem("user",me);
//retrieve object
console.log(localStorage.getItem("user")); // will output "[object Object]"

Answer 6

If the data is structured in JSON form (it's unclear if Angular utilizes a different structure), you may be able to utilize the setItem() and getItem() functions for updating and retrieving items from local storage!

Here is an example referenced from the following article:

var me = {name:'myname',age:99,gender:'myGender'};
localStorage.setItem("user",me);
//retrieve object
console.log(localStorage.getItem("user")); // will output "[object Object]"

Answer 7

Answer №4

If you're looking to utilize the full functionality of Angular, check out the robust Angular module known as angular-local-storage

This AngularJS module allows seamless access to your browser's local storage with a cookie fallback option

Implementation of 'set' function:

myApp.controller('MainCtrl', function($scope, localStorageService) {
  //...
  function submit(key, val) {
   return localStorageService.set(key, val);
  }
  //...
});

And now for the 'get' function:

myApp.controller('MainCtrl', function($scope, localStorageService) {
  //...
  function getItem(key) {
   return localStorageService.get(key);
  }
  //...
});

Answer 8

If you're looking to utilize the full functionality of Angular, check out the robust Angular module known as angular-local-storage

This AngularJS module allows seamless access to your browser's local storage with a cookie fallback option

Implementation of 'set' function:

myApp.controller('MainCtrl', function($scope, localStorageService) {
  //...
  function submit(key, val) {
   return localStorageService.set(key, val);
  }
  //...
});

And now for the 'get' function:

myApp.controller('MainCtrl', function($scope, localStorageService) {
  //...
  function getItem(key) {
   return localStorageService.get(key);
  }
  //...
});

Answer 9

Answer №5

If you try using setItem, it won't update the existing item in localStorage but create a new one with the same name.

Instead, simply use:

localStorage.item = (whatever modification you want to make)

Answer 10

If you try using setItem, it won't update the existing item in localStorage but create a new one with the same name.

Instead, simply use:

localStorage.item = (whatever modification you want to make)

What is the best way to modify items in localStorage?

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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