Mozilla , even though Firefox uses an add-on system based on the WebExtensions API, developers do not intend to fully adhere to the future third edition of the Chrome manifest for extensions. In particular, Firefox will continue to support the blocking mode operation of the API. , which allows for real-time content modification and is sought after in ad blockers and content filtering systems.
The main idea behind transitioning to the WebExtensions API was to unify the extension development technology for Firefox and Chrome, so in its current form, Firefox is nearly 100% compatible with the latest second version of the Chrome manifest. The manifest defines the list of capabilities and resources provided to extensions. Due to the introduction of restrictive measures in the third version of the manifest, which are negatively perceived by extension developers, Mozilla will depart from the practice of fully adhering to the manifest and will not implement changes in Firefox that violate compatibility with extensions.
Recall that , Google plans to discontinue support for the blocking mode of the webRequest API in Chrome, limiting it to read-only mode and offering a new declarative API for content filtering. . While the webRequest API allowed custom handlers with full access to network requests and capable of modifying traffic on the fly, the new declarativeNetRequest API provides access to a built-in universal filtering engine that processes blocking rules autonomously, does not allow the use of custom filtering algorithms, and prevents the establishment of complex overlapping rules based on conditions.
Mozilla is also assessing the feasibility of transferring support for certain other changes from the third version of the Chrome manifest to Firefox, which would violate compatibility with extensions:
- Transitioning to the execution of Service workers in the form of background processes will require developers to modify the code of certain extensions. Although the new method is more efficient in terms of performance, Mozilla is considering maintaining support for the execution of background pages.
- The new granular permission request model means that extensions will no longer be able to activate their permissions for all pages at once (the 'all_urls' permission has been removed) and will instead work only in the context of the active tab, meaning users will need to confirm the extension's operation for each website. Mozilla is exploring ways to strengthen access control without constantly distracting the user.
- Changes to Cross-origin request handling — according to the new manifest, the same permissions restrictions that apply to the main page will also apply to the content scripts that are injected (for example, if the page does not have access to the location API, then the extension script will not gain that access either). This change is planned to be implemented in Firefox.
- Prohibition of executing code loaded from external servers (referring to situations where an extension loads and executes external code). Firefox already blocks external code, and Mozilla developers are open to strengthening this protection by applying additional tracking techniques for code download suggested in the third version of the manifest.
Source: opennet.ru
