iOS Web Layer

Overview

ios/web performs a similar role on iOS as what content/ does on other platforms. It encapsulates the architecture for displaying web content, managing navigation, and providing an API that embedders (like ios/chrome, ios/web_view) can use to build a browser (or browser-like application).

On iOS, Blink is not available. Instead, ios/web wraps WKWebView (provided by WebKit) and layers on top of it to provide features like:

• WebState: The core class representing a tab/page (analogous to content::WebContents).
• BrowserState: Represents a user's session (analogous to content::BrowserContext).
• JavaScript Messaging: A channel for two-way communication between the embedder and JavaScript running in the page content.
• Navigation: Abstractions over WKWebView's navigation stack.

Minimum Deployment Version

//ios/web supports iOS 16 and above. This is a lower minimum iOS version than Chrome in order to support //ios/web_view deployment to older versions of iOS.

Layering & Dependencies

The ios/web layer sits above base, net, components, ui, and more. It is the renderer equivalent on iOS.

ios/web vs ios/components vs components/

• ios/web: The renderer-equivalent on iOS. It does not depend on higher-level features found in ios/chrome or ios/web_view.
• ios/components: Contains reusable feature code that is specific to iOS but shared across multiple embedders (e.g., ios/chrome and ios/web_view). Implementations in ios/components often depend on ios/web/public. See //ios/components/README.md.
• components/: Generally cross-platform, sometimes excluding iOS. See //components/README.md.

Dependency Notes:

• ios/components can depend on ios/web.
• ios/web can depend on ios/components, so long as the component does not depend on ios/web.

Usage

Embedders (like ios/chrome or ios/web_view) must consume ios/web through the Public API, located in ios/web/public.