A component URL is a URL that locates a component, including its declaration, program, and assets. Component URLs are resolved to component declarations by a resolver.
The primary use of component URLs is to identify a component in the definition of a component instance, as part of a child declaration.
You should not use component URLs to identify component instances, as multiple component instances can share the same URL. For that purpose, instead use monikers.
A component URL can, in principle, have any scheme. Some common schemes you may encounter are:
A fuchsia-pkg component URL is a package URL that locates a component distributed in a Fuchsia package.
It has the same format as package URL, with a resource path relative to the package root that locates a component manifest. This path is usually of the form meta/<manifest_name>.cm.
fuchsia-pkg://<repo-hostname>[/<pkg-name>[/<pkg-variant>][?hash=<pkg-hash>][#<path-to-manifest>]]
Example:
fuchsia-pkg://fuchsia.com/stash#meta/stash_secure.cm
A fuchsia-boot component URL locates a component in the system boot image. This scheme is used to identify components that must be resolved during early boot before a fuchsia-pkg resolver is available. It has the following format:
fuchsia-boot:///<path-to-manifest-in-bootfs>
Example:
fuchsia-boot:///#meta/driver_manager.cm
An http(s) component URL identifies a web page as a component. Such a component could be executed as a web page in a web runner, for example.
Example:
https://en.wikipedia.org/wiki/Hippos
