How is HTML5 localStorage Isolated: Per Page or Domain?

localStorage Isolation in HTML5: Per Page or Domain?

In HTML5, the localStorage object provides a convenient mechanism to store persistent data on the client-side. However, it's crucial to understand the scope of this storage to determine how to name your localStorage keys effectively.

Per Page/Domain Isolation: The Query

The question arises: is the HTML5 localStorage object isolated per page or domain? This consideration is particularly relevant when naming localStorage keys and managing data privacy and organization.

The Answer: Same Origin Policy

The answer lies in the concept of the same-origin policy in HTML5. The localStorage object is segregated based on the same-origin policy, which restricts data sharing between different origins. In this context, an origin refers to a domain and port combination.

Therefore, the localStorage object is isolated per domain and port. This means that different pages on the same domain and port can access the same localStorage data, while pages on different domains or ports have separate localStorage objects.

Implications for Key Naming

This isolation has implications for naming your localStorage keys. While you don't necessarily need a separate prefix for your keys, it can be a good idea if you plan to develop multiple applications within the same domain or port. Using a prefix can help distinguish keys and prevent conflicts with other applications or scripts.

Other Considerations

In situations where you want data to be isolated per page, you could consider using a key based on the location object or any other suitable approach that provides uniqueness for each page.

Ultimately, the decision of whether or not to use a prefix and how to name your localStorage keys depends on your specific requirements and organizational preferences. Understanding the scope and isolation of the localStorage object will empower you to optimize your data storage strategies and maintain data privacy in your HTML5 applications.

The above is the detailed content of How is HTML5 localStorage Isolated: Per Page or Domain?. For more information, please follow other related articles on the PHP Chinese website!