By principle, HTTP is stateless. Meaning, unlike applications, once closed, that’s it, it can be cleared.
Local storage has great advantages. It allows the user to avoid needing to log in. All the data needed is right there. Secondly, it can also be used to stay under data pull caps on API services.
Cookies are the traditional form of storing locally. However, cookies are data capped at 4 KB. Moreover, many people block them, knowing the security risk they can hold.
However, in HTML5, local storage can store any type of data. This is accomplished by converting all to a string via JSON and pulling it back, outside of the string in.
To store data, the localstorage object can be used. Using setItem(), getItem(), and removeItem() methods, data strings can be stored, retrieved, and deleted. Data is stored as key-value pairs, separated by a comma. To store only temporarily, the sessionStorage object can be used instead. To clear all of local storage, the empty clear() method can be used.
To stringify data, use JSON.stringify() as a wrapper for the value for the set, and JSON.parse() as a total wrapper for the get.
Example:
localStorage.setItem( 'cat', JSON.stringify(catdata) );
JSON.parse( localStorage.getItem( 'cat' ) ) ;
No critical data for functionality should be stored locally, as this can not be relied on. Users can at any time clear their local data or decide to only browse in private mode.
How many of these techniques still work? How well have isolate tabs features stopped tracking? What percentage of users browse in private mode? Can this be exploited by big companies to reduce their running costs by storing locally on users’ computers?