Is it possible to alter local storage settings?

Question

Is it possible to alter local storage settings?

I've integrated simplecartjs into my online store to manage product data. The data is stored in local storage and currently looks like this:

{"SCI-1":{"quantity":1,"id":"SCI-1","price":20,"name":"Matt Black Tape","size":"Empty"},"SCI-3":{"quantity":1,"id":"SCI-3","price":19,"name":"Mohawk Soundproofing Mat 48 x 39cm"},"SCI-5":{"quantity":2,"id":"SCI-5","price":8,"name":"Car Speaker Air Freshener","color":"Green Tea"},"SCI-7":{"quantity":1,"id":"SCI-7","price":50,"name":"Installation Package"},"SCI-9":{"quantity":1,"id":"SCI-9","price":30,"name":"Quartz Films","color":"Yellow","size":"50cm x 30cm"},"SCI-11":{"quantity":1,"id":"SCI-11","price":30,"name":"Quartz Films","color":"True Blue","size":"50cm x 30cm"}}

Now, I want to include the following line before it closes.

"SCI-12":{"quantity":1,"id":"SCI-12","price":5,"name":"Shipping Costs"}

However, the number of products may vary based on the user, so SCI-12 should adjust accordingly with the items.

EDIT It doesn't have to be SCI-1, any identifier will work as long as it comes after the items.

EDIT2 I'm attempting the following code... But it's not working as expected.

$("#matkahuolto").click(function(){
    var value_object = '"Shipping Costs":{"quantity":1,"id":"Shipping Costs","price":5,"name":"Shipping Costs"}';
    var json_object = JSON.parse(localStorage.your_json); // convert string to object

    json_object["simpleCart_items"] = value_object; // add value

    localStorage.your_json = JSON.stringify(json_object);  // store it again.

    });

    $("#posti").click(function(){
    var json_object = JSON.parse(localStorage.your_json); // convert string to object

    json_object["simpleCart_items"] = value_object; // add value

    localStorage.your_json = JSON.stringify(json_object);  // store it again.

    });

EDIT3 A snapshot of the local storage.

javascript local-storage

Answer 1

Answer №1

Understanding how items are stored in localStorage is crucial. It functions like a hashmap/dictionary where items are saved in key-value pairs.

For instance, to store a string in localStorage, you would use:

localStorage["myKey"] = "some value";

To retrieve the value later, you simply reverse the process:

var myValue = localStorage["myKey"];

It's important to note that only strings can be stored in localStorage. If you wish to store an object, you must first convert it into a string format, usually using JSON. The JSON.stringify method converts an object to JSON, and JSON.parse does the opposite.

Here's an example of converting an object to JSON:

var someObject = {id: 1, name: 'Test'};

var jsonSomeObject = JSON.stringify(someObject);
// jsonSomeObject now looks like "{"id":1,"name":"test"}"

To read an object from JSON:

someObject = JSON.parse(jsonSomeObject);

In your case, assuming your object contains the necessary data, you can simply stringify your object and add it to localStorage with a specific key:

var jsonData = JSON.stringify({"SCI-12":{"quantity":1,"id":"SCI-12","price":5,"name":"Toimituskulut"}});

localStorage["aKey"] = jsonData;

When you need to access this data later:

var mySCI = JSON.parse(localStorage["aKey"])

If you want to update a specific entry in localStorage, read it in, make changes, and then overwrite it:

var mySCI = JSON.parse(localStorage["aKey"]);
mySCI.SCI-12.quantity = 2;
localStorage["aKey"] = JSON.stringify(mySCI);

Remember that while most browsers support JSON natively, older ones may not. You can include Douglass Crockford's JSON-js script for compatibility.

Edit:

Based on the screenshot provided, it appears that values are stored under the key simpleCart_items in localStorage (not your_json as used in the code) and object keys follow a pattern like "SCI-1". To work with this structure:

 $("#matkahuolto").click(function(){
    var value_object = {quantity: 1, id: 1, name: "someName"} ; 
    var jsonObject = JSON.parse(localStorage["simpleCart_items"]);
    json_object["SCI_1"] = value_object; // add value

 localStorage["simpleCart_items"] = JSON.stringify(json_object);  // store it again.

});

$("#posti").click(function(){
 // convert string to object
 var json_object = JSON.parse(localStorage["simpleCart_items"]); 

json_object["SCI-1"] = value_object; // add value

 localStorage["simpleCart_items"] = JSON.stringify(json_object);  // store it again.

});

Answer 2

Understanding how items are stored in localStorage is crucial. It functions like a hashmap/dictionary where items are saved in key-value pairs.

For instance, to store a string in localStorage, you would use:

localStorage["myKey"] = "some value";

To retrieve the value later, you simply reverse the process:

var myValue = localStorage["myKey"];

It's important to note that only strings can be stored in localStorage. If you wish to store an object, you must first convert it into a string format, usually using JSON. The JSON.stringify method converts an object to JSON, and JSON.parse does the opposite.

Here's an example of converting an object to JSON:

var someObject = {id: 1, name: 'Test'};

var jsonSomeObject = JSON.stringify(someObject);
// jsonSomeObject now looks like "{"id":1,"name":"test"}"

To read an object from JSON:

someObject = JSON.parse(jsonSomeObject);

In your case, assuming your object contains the necessary data, you can simply stringify your object and add it to localStorage with a specific key:

var jsonData = JSON.stringify({"SCI-12":{"quantity":1,"id":"SCI-12","price":5,"name":"Toimituskulut"}});

localStorage["aKey"] = jsonData;

When you need to access this data later:

var mySCI = JSON.parse(localStorage["aKey"])

If you want to update a specific entry in localStorage, read it in, make changes, and then overwrite it:

var mySCI = JSON.parse(localStorage["aKey"]);
mySCI.SCI-12.quantity = 2;
localStorage["aKey"] = JSON.stringify(mySCI);

Remember that while most browsers support JSON natively, older ones may not. You can include Douglass Crockford's JSON-js script for compatibility.

Edit:

Based on the screenshot provided, it appears that values are stored under the key simpleCart_items in localStorage (not your_json as used in the code) and object keys follow a pattern like "SCI-1". To work with this structure:

 $("#matkahuolto").click(function(){
    var value_object = {quantity: 1, id: 1, name: "someName"} ; 
    var jsonObject = JSON.parse(localStorage["simpleCart_items"]);
    json_object["SCI_1"] = value_object; // add value

 localStorage["simpleCart_items"] = JSON.stringify(json_object);  // store it again.

});

$("#posti").click(function(){
 // convert string to object
 var json_object = JSON.parse(localStorage["simpleCart_items"]); 

json_object["SCI-1"] = value_object; // add value

 localStorage["simpleCart_items"] = JSON.stringify(json_object);  // store it again.

});

Answer 3

Answer №2

When using LocalStorage, keep in mind that all data is stored as a string of text. It's best to make modifications before it gets converted into a string.

If you need to add a property to the JSON string, you'll have to first convert it into an object, add the property, then convert it back to a string for storage.

Code Example

var json_obj = JSON.parse(localStorage.your_data); // turn string into object
json_obj[key] = value; // add the property
localStorage.your_data = JSON.stringify(json_obj);  // store it again.

Important Note

Consider using indexedDB as an alternative solution.
It offers more flexibility and robustness compared to LocalStorage.

Answer 4

When using LocalStorage, keep in mind that all data is stored as a string of text. It's best to make modifications before it gets converted into a string.

If you need to add a property to the JSON string, you'll have to first convert it into an object, add the property, then convert it back to a string for storage.

Code Example

var json_obj = JSON.parse(localStorage.your_data); // turn string into object
json_obj[key] = value; // add the property
localStorage.your_data = JSON.stringify(json_obj);  // store it again.

Important Note

Consider using indexedDB as an alternative solution.
It offers more flexibility and robustness compared to LocalStorage.

Is it possible to alter local storage settings?

Answer №1

Answer №2

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