I had created two arrays to store an array of data into local storage. I'm storing it by creating an array of array. But not able to remove the value.
`var divMappingArray = new Array();
var data = new Array();
data[0] = {"ID": 123, "Name": "temp" };
divMappingArray.push(data[0]);
data[1] = {"ID": 23, "Name": "temp1" };
divMappingArray.push(data[1]);`
localStorage.setItem('zoneObject', JSON.stringify(divMappingArray));
I'm saving this into local storage, but I need to remove a value based on name or id. I tried looping it and remove the item, but this is not working for me.
$.each($.parseJSON(retrievedObject), function(i, value){
delete value.ID[i];
});
Parsing the array value by retrieving from local storage and want to add the updated data into local storage back.
While removing i want to remove the whole set of array value both ID and name, the retrieved data length will be reduced after the removal.
After modifying the aray, you need to update the local storage
var rarray = $.parseJSON(retrievedObject);
$.each(rarray, function (i, value) {
if (value.ID == 23) {
rarray.splice(i, 1);
return false;
}
});
localStorage.setItem('zoneObject', JSON.stringify(rarray));
Demo: Fiddle
Related
how can I change the "ABC" field in the code below?
var data = {ABC:{key:'dynamic_key',value:'dynamic_value'}}
Normally, I can give the value I want by saying data.ABC.key, but what I really want is to go as data.CCC instead of data.ABC, so I just want to change the ABC name.
Re-assign the inner object to the new outer object key, then delete the previous.
var data = {ABC:{key:'dynamic_key',value:'dynamic_value'}}
data.CCC = {...data.ABC}
delete data.ABC
console.log(data)
That also could be (without using delete)
var data = {ABC:{key:'dynamic_key',value:'dynamic_value'}}
data = {CCC: data.ABC}
console.log(data)
EDIT... It you want to use a string from a variable to set the new key, use the bracket notation:
var data = {ABC:{key:'dynamic_key',value:'dynamic_value'}}
var newKey="CAR"
data[newKey] = data.ABC
delete data.ABC
console.log(data)
data.CCC = data.ABC // on object create new key name. Assign old value to this
delete data.ABC //delete object with old key name
output:
{
"CCC":
{
"key": "dynamic_key",
"value": "dynamic_value"
}
}
I am scraping websites using CasperJS and one of the tasks involve crawling across url set by a for loop counter. The url looks like this
www.example.com/page/no=
where the no is any number from 0-10 set by the for loop counter. The scraper then goes through all the pages, scrapes the data into a JSON object and repeats until no=10.
The data that I am trying to get is stored in discrete groups in each page- what I would like to work with is a single JSON object by joining all the scraped output from each page.
Imagine Page1 has Expense 1 and the object I am getting is { expense1 } and Page 2 has Expense 2 and object that I am getting is { expense2 }. What I would like to have is one JSON at the end of scraping that looks like this:
scrapedData = {
"expense1": expense1,
"expense2": expense2,
}
What I am having trouble is joining all the JSON object into one array.
I initialized an empty array and then each object gets pushed to array.
I have tried a check where if iterator i in for loop is equal to 10, then the JSON object is printed out but that didnt seem to work. I looked up and it seems Object spread is an option but I am not sure how to use it this case.
Any pointers would be helpful. Should I be using any of the array functions like map?
casper.then(function(){
var url = "https:example.net/secure/SaFinShow?url=";
//We create a for loop to go open the urls
for (i=0; i<11; i++){
this.thenOpen(url+ i, function(response){
expense_amount = this.fetchText("td[headers='amount']");
Date = this.fetchText("td[headers='Date']");
Location = this.fetchText("td[headers='zipcode']");
id = this.fetchText("td[headers='id']");
singleExpense = {
"Expense_Amount": expense_amount,
"Date": Date,
"Location": Location,
"id": id
};
if (i ===10){
expenseArray.push(JSON.stringify(singleExpense, null, 2))
this.echo(expenseArray);
}
});
};
});
Taking your example and expanding on it, you should be able to do something like:
// Initialize empty object to hold all of the expenses
var scrapedData = {};
casper.then(function(){
var url = "https:example.net/secure/SaFinShow?url=";
//We create a for loop to go open the urls
for (i=0; i<11; i++){
this.thenOpen(url+ i, function(response){
expense_amount = this.fetchText("td[headers='amount']");
Date = this.fetchText("td[headers='Date']");
Location = this.fetchText("td[headers='zipcode']");
id = this.fetchText("td[headers='id']");
singleExpense = {
"Expense_Amount": expense_amount,
"Date": Date,
"Location": Location,
"id": id
};
// As we loop over each of the expenses add them to the object containing all of them
scrapedData['expense'+i] = singleExpense;
});
};
});
After this runs the scrapedData variable should be of the form:
scrapedData = {
"expense1": expense1,
"expense2": expense2
}
Updated code
One problem with the above code is that inside the for loop when you loop over the expenses, the variables should be local. The variable names also should not be Date and Location since those are built-in names in JavaScript.
// Initialize empty object to hold all of the expenses
var scrapedData = {};
casper.then(function(){
var url = "https:example.net/secure/SaFinShow?url=";
//We create a for loop to go open the urls
for (i=0; i<11; i++){
this.thenOpen(url+ i, function(response){
// Create our local variables to store data for this particular
// expense data
var expense_amount = this.fetchText("td[headers='amount']");
// Don't use `Date` it is a JS built-in name
var date = this.fetchText("td[headers='Date']");
// Don't use `Location` it is a JS built-in name
var location = this.fetchText("td[headers='zipcode']");
var id = this.fetchText("td[headers='id']");
singleExpense = {
"Expense_Amount": expense_amount,
"Date": date,
"Location": location,
"id": id
};
// As we loop over each of the expenses add them to the object containing all of them
scrapedData['expense'+i] = singleExpense;
});
};
});
This is my code. I am trying since a couple of days to create an Array of Objects, which I will then store in Local Storage. Here is the problem, I need to first Get the existing value from Local Storage.
I then need to add the new data object to the existing array. I then convert it into JSON so that I can store it back in the local storage.
onRegisterSubmit(){
const user = {
a: this.a,
b: this.b,
c: this.c,
id: Date.now()
}
var abc = [];
var get = JSON.parse(localStorage.getItem('user'));
abc = [get];
abc.push(user);
localStorage.setItem('user', JSON.stringify(abc));
console.log(JSON.stringify(abc));
console.log(get);
}
I want the JSON to be an array of objects like this,
[{"hour":1,"minute":21,"ampm":"PM","repeatDays":[],"message":"","todayOrTomorrow":"Tomorrow","isRepeatMode":false,"isEnabled":false,"id":"1493797882440"},{"hour":1,"minute":24,"ampm":"PM","repeatDays":[],"message":"","todayOrTomorrow":"Tomorrow","isRepeatMode":false,"isEnabled":false,"id":"1493797896257"},{"hour":6,"minute":14,"ampm":"PM","repeatDays":[],"message":"","todayOrTomorrow":"Tomorrow","isRepeatMode":false,"isEnabled":false,"id":"1493815470408"}]
This is my JSON.
[[[[[[[{"id":1493820594019},{"id":1493820606448}],{"id":1493820609111}],{"id":1493820610150}],{"id":1493820610553}],{"id":1493820610827}],{"id":1493820611015}],{"id":1493820612018}]
I've been trying for several days and any help will be greatly appreciated.
The issues with that code are:
You're wrapping the result you get in an array, but in theory, you want to already have an array.
You're storing user, not get or abc. (You removed that with an edit.)
To store the array, do what you're doing:
localStorage.setItem("users", JSON.stringify(users));
To get the array:
users = JSON.parse(localStorage.getItem("users") || "[]");
Note how that provides a default (empty array) if getItem returns null because we've never stored our users there.
To add a user to the array:
users.push({id: 1, foo: "bar"});
Example (live on jsFiddle [Stack Snippets don't allow local storage]):
(function() { // Scoping function to avoid creating globals
// Loading
var users = JSON.parse(localStorage.getItem("users") || "[]");
console.log("# of users: " + users.length);
users.forEach(function(user, index) {
console.log("[" + index + "]: " + user.id);
});
// Modifying
var user = {
id: Math.floor(Math.random() * 1000000)
};
users.push(user);
console.log("Added user #" + user.id);
// Saving
localStorage.setItem("users", JSON.stringify(users));
})();
That shows you the list of current users in the console, adding one each time you refresh the page.
Try something like this:-
link https://jsfiddle.net/sureshraina/nLexkyfw/1/
var mydatas = new Array();
mydatas[0] = "data";
mydatas[1] = "data1";
mydatas[2] = "data2";
localStorage["mydatas"] = JSON.stringify(mydatas);
var datas = JSON.parse(localStorage["mydatas"]);
See this post.
You can't store Objects, you have to store a String. So the workaround is to stringify your Object before you store it (for example, you could use change it to a JSON object, store it, and read it again when needed).
In local storage I have an object named favourites and it contains this..
"{
"id3333":{
"URL":"somewhere.comm/page1/",
"TITLE":"Page 1 Title",
},
"id4444":{
"URL":"somewhere.comm/page2/",
"TITLE":"Page 2 Title",
}
}"
How can I delete an object based on its ID (id3333 & id4444 for examples)
I have tried the following along with some other voodoo..
localStorage.removeItem('id3333'); // no errors, no removal
localStorage.removeItem('favourites':'id3333'); // SyntaxError: missing ) after argument list
localStorage.removeItem('favourites[id3333]'); // no errors, no removal
localStorage.removeItem('id3333', JSON.stringify('id3333')); // no errors, no removal
Also, I will need to get the key name to delete based on a variable, so like this..
var postID = 'id3333';
localStorage.removeItem(postID);
or
var objectName = 'favourites';
var postID = 'id3333';
localStorage.removeItem(objectName[postID]);
Is it possible to remove a nested item directly or do I need to retrieve the full object and then delete the item and then set the object back to local storage again?
The closest I can get to deleting anything directly so far is..
localStorage.removeItem('favourites');
But that of course removes the entire object.
You have a a single key and you are acting like there are multiple keys
var obj = {
"id3333":{
"URL":"somewhere.comm/page1/",
"TITLE":"Page 1 Title",
},
"id4444":{
"URL":"somewhere.comm/page2/",
"TITLE":"Page 2 Title",
}
};
window.localStorage.favs = JSON.stringify(obj); //store object to local storage
console.log("before : ", window.localStorage.favs); //display it
var favs = JSON.parse(window.localStorage.favs || {}); //read and convert to object
var delKey = "id3333"; //key to remove
if (favs[delKey]) { //check if key exists
delete favs[delKey]; //remove the key from object
}
window.localStorage.favs = JSON.stringify(favs); //save it back
console.log("after : ", window.localStorage.favs); //display object with item removed
With localStorage.removeItem you can only remove top level keys, i.e. keys directly on localStorage.
Because id3333 is on localStorage.favourites you cannot remove it using localStorage.removeItem.
Instead try delete localStorage.favourties['id3333']
Simple, actually: you just delete it. :)
x = {
"id3333":{
"URL":"somewhere.comm/page1/",
"TITLE":"Page 1 Title",
},
"id4444":{
"URL":"somewhere.comm/page2/",
"TITLE":"Page 2 Title",
}
};
console.log(x);
delete x.id3333;
console.log(x);
delete does what you're looking for. You could also do something like delete x.id3333.TITLE if you were so inclined. Note also that delete returns true if successful and false if not.
Suppose you set a nested object in localStorage like that
const dataObj = {
uid: {
name: 'robin',
age: 24,
}
}
window.localStorage.setItem('users', JSON.stringify(dataObj));
Now you want to delete the age property. You can't remove it with removeItem native function since it allows to delete from top level.
So you need to get the data first and delete the property you want and set the data again to localStorage with updated value like that
const existingLocalStorage = JSON.parse(window.localStorage.getItem('users') || {});
if(existingLocalStorage['uid']['age']) { // if throws any error, use lodash get fucntion for getting value
delete existingLocalStorage['uid']['age'];
}
window.localStorage.setItem('users', JSON.stringify(existingLocalStorage));
what I need
I need to toggle image on click.
like if user select favorite choice & then it mark unfavorite image is altered and data is deleted from localstoarge.
html code
<div style="display:block; float:right; width:auto; color:#7c7c7c;">
</div>
js code
function favaorite(sess_id,name,city,country,event_url,pointer){
var eventData;
//is anything in localstorage?
if (localStorage.getItem('eventData') === null) {
eventData = [];
} else {
// Parse the serialized data back into an array of objects
eventData = JSON.parse(localStorage.getItem('eventData'));
//alert(eventData);
$.each(eventData, function(key, value){
//console.log(value);
var imageUrl='http://im.gifbt.com/images/star1_phonehover.png';
//var imageUrl='http://im.gifbt.com/images/star1_phone.png';
$(pointer).closest('.evt_date').find('.favourate_dextop').css('background-image', 'url("' + imageUrl + '")');
//$(pointer).closest('.evt_date').find('.favourate_dextop').css('background-image', 'url("' + imageUrl + '")');
});
}
var details={};
details.sess_id=sess_id;
details.name=name;
details.city=city;
details.country=country;
details.event_url=event_url;
// Push the new data (whether it be an object or anything else) onto the array
eventData.push(details);
// Alert the array value
//alert(eventData); // Should be something like [Object array]
// Re-serialize the array back into a string and store it in localStorage
var jsondata=localStorage.setItem('eventData', JSON.stringify(eventData));
}
problem
I'm new in localstorage I need to know how could I delete data from json string.
I have implemented add to favorite now I need to mark unfavorite.
data is stored:
[{
"sess_id":182104,
"name":"AUTOMECH FORMULA",
"city":"Cairo",
"country":"Egypt",
"event_url":"automech-formula"
},]
To delete data from localstorage you use localStorage.removeItem('itemNam')
example
localStorage.setItem('name','hello');
to delete the name item from the localStorage you use
localStorage.removeItem('name');
BUT IF YOUR QUESTION IS HOW TO DELETE DATA FROM JSON OBJECT THEN YOU HAVE TWO METHODS
1: changing the original json object
delete originalJson.attributeName
originalJson = {name:'myname',age:30};//our object to test with
example :
delete originalJson.age //in this case originalJson.age is no more available
2: don't change the original object and make another copy instead
originalJson2 = JSON.stringify(originalJson);
originalJson2 = JSON.parse(originalJson2);
delete originalJson2.age //originalJson.age is available but originalJson2.age is not available
here is the : jsfiddle
let assume that sess_id is your unique id for events
function unfavorite(sess_id){
var eventData = localStorage.getItem('eventData');
//is anything in localstorage?
if (localStorage.getItem('eventData') === null) {
console.log('invalid event');
}
eventData = JSON.parse(eventData);
// Keep all without the one with specified sess_id
$.grep(eventData, function(value) {
return value.sess_id != sess_id;
});
var jsondata=localStorage.setItem('eventData', JSON.stringify(eventData));
}