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Use localStorage with JavaScript.
I usually wish to rewrite localStorage to implement a sure operate. What are the strategies to rewrite the strategies in localStorage? There are numerous builders who wish to rewrite the strategies in localStorageto comprehend the expiration time of the important thing, or to observe the learn and write of the important thing. So what are the strategies to override the strategies in localStorage. That is my forty third Medium article.
Many builders like the concept of rewriting, first maintaining the unique methodology after which rewriting the tactic instantly on localStorage like under.
Nonetheless, this fashion of writing shouldn’t be overriding the tactic setItem(), however so as to add a setItem attribute to localStorage. When the worth attribute of the tactic is asserted, the native setItem() methodology is overwritten.
I haven’t examined it an excessive amount of, however in some browsers, this attribute might be ignored and inflicting our rewriting to fail.
If we glance intently, setItem and getItem are inherited from Storage __proto__ pseudo property.
Then we instantly override the above localStorage.__proto__ methodology.
This implements the true override of the setItem() methodology.
However there may be nonetheless an issue right here. Each localStorage and sessionStorage inherit from Storage. After rewriting the properties or strategies on localStorage.__proto__, the strategies in sessionStorage are additionally rewritten.
We don’t instantly modify the tactic of localStorage itself, however wrap a layer on the skin, after which use localStorage to comprehend the storage operate on the backside layer.
On this means, the diploma of freedom is comparatively increased, and there’s no compatibility downside in Part 1. Solely the identify used has modified and the properties and strategies in localStorage are fully blocked.
If you wish to use a customized object with out the pack then it is advisable implement all of the properties and strategies. It’s not potential to mock a way alone just like the above.
Use Object.definePropertyor Proxyequal to fully overriding the localStorage variable. Higher than Part 3 in that the identify has not modified.
4.1 Direct protection, no impact
If you happen to use the next methodology to cowl instantly, it would haven’t any impact.
window.localStorage = Object.create(null); console.log(window.localStorage); //nonetheless native
We get the property descriptor of localStorage by means of Object.getOwnPropertyDescriptor. It may be discovered that there isn’t a writable: true attribute, which implies that localStorage shouldn’t be instantly writable.
4.2 Overriding with Object.defineProperty
Since there isn’t a writableattribute, we’ll add one to it. We are able to override localStorage with Object.defineProperty.
However you’ll be able to’t use the above writing methodology with one layer exterior. If you happen to instantly give the above myLocalStorage to localStorage then it would generate infinite recursion (to keep away from deceptive, the flawed writing methodology is not going to be written right here).
I’ve made a backup of localStorage right here. If you happen to want a local methodology then you may also function it.
On this article, we don’t particularly implement a operate equivalent to setting the expiration time. However discuss the right way to rewrite localStorage or the strategies in it from one other perspective.
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