How do I update local storage array with new items

[Deon]

Hi
Please can you provide a tutorial on how to

1.create an array in local storage

1. retrieve the contents of the array

2. update and append to the array

   Thanks

[Serhii Kulibaba]

Hello Deon,

Please use a method "update" for that: https://docs.appery.io/reference#jque...

1) Read a Storage value to the local variable
2) Add new items to that variable
3) Update the Storage variable with that local variable, using a method "update"

[Deon]

Thanks, but I asked how to Update an Array.
That is not the right link. It is just normal updates of storage variables which I am familiar with.

[Jeffry Reed]

Hi Deon,

There are many ways to do this. I have been learning more about how to use lodash, its bundled with the app. Another great resource is Stackoverflow

Here is some information for you

SET
localStorage.setItem("localVarName", JSON.stringify(varName));

GET
var varName = JSON.parse( localStorage.getItem("localVarName"));

Put anything into an array using Array.push().

var a=[], b={};
a.push(b);
// a[0] === b;

Extra information on Arrays

Add more than one item at a time

var x = ['a'];
x.push('b', 'c');
// x = ['a', 'b', 'c']

Add items to the beginning of an array

var x = ['c', 'd'];
x.unshift('a', 'b');
// x = ['a', 'b', 'c', 'd']

Add the contents of one array to another

var x = ['a', 'b', 'c'];
var y = ['d', 'e', 'f'];
x.push.apply(x, y);
// x = ['a', 'b', 'c', 'd', 'e', 'f']
// y = ['d', 'e', 'f'] (remains unchanged)

Create a new array from the contents of two arrays

var x = ['a', 'b', 'c'];
var y = ['d', 'e', 'f'];
var z = x.concat(y);
// x = ['a', 'b', 'c'] (remains unchanged)
// y = ['d', 'e', 'f'] (remains unchanged)
// z = ['a', 'b', 'c', 'd', 'e', 'f']

http://stackoverflow.com/questions/62...

Or, something like this would work, I have been implementing MobiScroll which requires working the JS level so I am learning... this is how I working with the array of objects, modify to your needs

function AddItems(data) {

Code: Select all

 var list = []; 

 for (var i = 0; i < data.length; i++) { 
     list.push({ 
         text1: data[i].text1, 
         text2: data[i].text2 
     }); 
 } 

}

[Deon]

Jeffry,
Brilliant. This is exactly what I needed. Thank you so much. You have saved me a lot of time with a thorough explanation and sample. I appreciate your assistance.

Here is a sample I did to test your code. The difference is that I am using a local storage array. I am adding and retrieving items which works perfectly. What helped me was your explanation of "x.push" to a variable first before updating the local storage, as there is no way to append items directly to local storage unless you are mapping???

var id = Apperyio.storage.User.get("$['tempUserID']");
x.push(id); //x is already declared as a global variable
Apperyio.storage.userIDlist.update("$['userID']", JSON.stringify(x));
var sendID=Apperyio.storage.userIDlist.get("$['userID']");
var i, s, myStringArray = JSON.parse(sendID), len = myStringArray.length;
for (i=0; i<len; ++i) {
if (i in myStringArray) {
s = myStringArray;
alert(s);
}
}