I am using JavaScript to store an array in local Storage. Reading this site gave me the idea of using JSON.stringify to convert the array to a string before storing it. This code works to convert an array to a JSON string for local storage.
localStorage["search_history_record"] = JSON.stringify(search_history_record);
My problem has been retrieving the array from local storage. I can parse the array from the stored string in local storage (I checked this using console.log), but this parsed array will not save properly.
search_history_record = JSON.parse(localStorage["search_history_record"]);
I've been unable to find a solution in other stack overflow questions to solve this problem so far. Why would this console log the stored string back to an array properly, but not store the parsed string back to my local array?
Related
As per my previous post, I was referred to create a new post.
As seen in the comments, there is a trail of progression for the issue, I'll rephrase here in this post:
I'm using a TamperMonkey script in FireFox.
I'm trying to persist a Dexie object/database into TamperMonkey's local storage with GM.setValue('unique-dexie-db-name', dexieDBvariable);
However when I go to retrieve this value (ex. I store this on google.com, and retrieve this on yahoo.com) with var dexieDB = GM.getValue('unique-dexie-db-name'); My returned object value is not a Dexie database object, but rather something else I can't use as a database.
My question: I'm unsure, but I think when storing this Dexie Database into TamperMonkey, it gets stored as a string, and, I should try to somehow JSON.stringify() the object fully in order to be able to reproduce and re-create it when I need it in the GM.getValue() call. How do I store this Javascript object as a string in order to be able to retrieve the value again as a whole later?
This is my working example code;
https://gist.github.com/n-bell/b375c80b638d3a59a250e903afb4a36b.js
https://gist.github.com/n-bell/b375c80b638d3a59a250e903afb4a36b
(second link looks better formatted in browser)
And, as stated before, I've tried playing around with JSON.parse() / JSON.stringify() but I'm not sure this is the path to go down.
I've a popup to enter the data and once the data is added, I need to show data in parent page Gridview. But that data don't need to be stored until I click the save button below the Gridview in the parent page. It will still be displayed and maintained on the screen - (like it has active/inactive button).
When I click the save below the gridview, it will be stored in the database all at once. I need to do this using javascript. How can I do that?
I'm working on asp.net web project.
You can save your data temporarily using localStorage instead of your database for instance:
localStorage.setItem('myDataName', 'myDataValue') // Save data
And:
localStorage.getItem('myDataName') // Get data
This works for strings. If you want to save objects or arrays of objects, you must convert them to strings like this:
localStorage.setItem('myDataName', JSON.stringify(myObject)) // Save object
Take a look at LocalStorage
The localStorage property allows you to access a local Storage object.
localStorage is similar to sessionStorage. The only difference is
that, while data stored in localStorage has no expiration time, data
stored in sessionStorage gets cleared when the browsing session
ends—that is, when the browser is closed.
It should be noted that data stored in either localStorage or
sessionStorage is specific to the protocol of the page.
Store Data
localStorage.setItem('Key', 'YOUR_DATA');
Read Data
var YOUR_DATA = localStorage.getItem('Key');
You can also store objects by stringifying it.
localStorage.setItem('Key', JSON.stringify(YOUR_DATA_OBJ));
when reading parse to object
var YOUR_DATA_OBJ = JSON.parse(localStorage.getItem('Key'));
I could read in the Chrome storage API page that we can store string values inside Chrome storage against keys. Is there any way to store files against keys inside Chrome storage?
chrome.storage stores data as the JSON stringification of the values which it's given to store. So, yes, if you convert your file(s) into a form that can be converted to JSON (e.g. by JSON.stringify()), then the contents of the file can be stored. If the value that you are trying to store in chrome.storage can not be converted to JSON, then it can't be stored (e.g. DOM elements). chrome.storage does not inherently care what the data represents, only that it can be JSON stringified.
If you're asking, as stated in your comment, if it's a good idea to store thousands of different "files" totaling more than 5GB in chrome.storage, then the answer is: "NO!".
If you are looking for alternatives, then some are provided in Can you use HTML5 local storage to store a file? If not, how?
I want to send some data from one HTML page to another. I am sending the data through the query parameters like http://localhost/project/index.html?status=exist. The problem with this method is that data remains in the URL. Is there any other method to send the data across HTML pages using JavaScript or jquery.
why don't you store your values in HTML5 storage objects such as sessionStorage or localStorage, visit HTML5 Storage Doc to get more details. Using this you can store intermediate values temporarily/permanently locally and then access your values later.
To store values for a session:
sessionStorage.setItem('label', 'value')
sessionStorage.getItem('label')
or more permanently:
localStorage.setItem('label', 'value')
localStorage.getItem('label')
So you can store (temporarily) form data between multiple pages using HTML5 storage objects which you can even retain after reload..
I know this is an old post, but figured I'd share my two cents. #Neji is correct in that you can use sessionStorage.getItem('label'), and sessionStorage.setItem('label', 'value') (although he had the setItem parameters backwards, not a big deal). I much more prefer the following, I think it's more succinct:
var val = sessionStorage.myValue
in place of getItem and
sessionStorage.myValue = 'value'
in place of setItem.
Also, it should be noted that in order to store JavaScript objects, they must be stringified to set them, and parsed to get them, like so:
sessionStorage.myObject = JSON.stringify(myObject); //will set object to the stringified myObject
var myObject = JSON.parse(sessionStorage.myObject); //will parse JSON string back to object
The reason is that sessionStorage stores everything as a string, so if you just say sessionStorage.object = myObject all you get is [object Object], which doesn't help you too much.
possibly if you want to just transfer data to be used by JavaScript then you can use Hash Tags
like this
http://localhost/project/index.html#exist
so once when you are done retriving the data show the message and change the
window.location.hash to a suitable value.. now whenever you ll refresh the page the hashtag wont be present
NOTE: when you will use this instead ot query strings the data being sent cannot be retrived/read by the server
Well, you can actually send data via JavaScript - but you should know that this is the #1 exploit source in web pages as it's XSS :)
I personally would suggest to use an HTML formular instead and modify the javascript data on the server side.
But if you want to share between two pages (I assume they are not both on localhost, because that won't make sense to share between two both-backend-driven pages) you will need to specify the CORS headers to allow the browser to send data to the whitelisted domains.
These two links might help you, it shows the example via Node backend, but you get the point how it works:
Link 1
And, of course, the CORS spec:
Link 2
~Cheers
Where are the data stored in local storage? Is it in form of some text or ASCII format or some other? Is it possible to store JSON data in text files (which can be regularly) updated and retrieve them back? I want to store some JSON data but since my requirement is not so big, I want to abstain from using a database for now.
Local storage can only store strings (any data you might have, have to be converted to string upon saving in storage and "revived" upon reading from it).
JSON data is more than fine to be stored as a string so it is good choice of format for keeping complex data in browser storage (either local storage or session storage).
You can learn more about storage here: http://diveintohtml5.info/storage.html
As to where the data is being stored, I imagine it varies from browser to browser but you don't have to worry about where is the data, since you don't have any direct access to it (only through storage API).
Edit: Quick note - I've found this article stating where is storage data stored by Firefox - https://developer.mozilla.org/en/DOM/Storage (see section "Storage location and clearing the data" at the bottom of the page).
I wrote a tiny script to allow storage, and reading of arrays, strings, and objects into local storage. IT even lets you modify nested keys within the objects you store. Here is a link to the tiny script. https://github.com/andresgallo/truStorage/blob/master/truStorage.js
Getting:
const got = JSON.parse(localStorage.getItem('my-key'));
Setting:
localStorage.setItem('my-key', JSON.stringify({ a: 'A' }));