Resources can be loaded in the context of another file, which
means that the path to the resource file must be resolved
before it can be loaded.
Previously the API of this interface did not allow the client
code to get access to the resolved URL which is used to load
the resource.
Now this API has been refactored so that you must do the
resource URL resolving first and the loading expects a
resolved URL.
PR Close#28199
Previously ngtsc assumed resource files (templateUrl, styleUrls) would be
physically present in the file system relative to the .ts file which
referenced them. However, ngc previously resolved such references in the
context of ts.CompilerOptions.rootDirs. Material depends on this
functionality in its build.
This commit introduces resolution of resources by leveraging the TypeScript
module resolver, ts.resolveModuleName(). This resolver is used in a way
which will never succeed, but on failure will return a list of locations
checked. This list is then filtered to obtain the correct potential
locations of the resource.
PR Close#27357
When a single resource is preloaded twice in ngtsc, the second request
would be recognized as in-flight in which case `undefined` would
be returned, which signals to the compilation that is can resume
synchronously. The compilation would then proceed immediately and call
`load`, only to find out that the request is still in-flight which is
not allowed.
This commit caches the Promise of the in-flight fetch requests, such
that subsequent preload requests can return the corresponding Promise
instance.
PR Close#27357
This commit adds support for templateUrl in component templates within
ngtsc. The compilation pipeline is split into sync and async versions,
where asynchronous compilation invokes a special preanalyze() phase of
analysis. The preanalyze() phase can optionally return a Promise which
will delay compilation until it resolves.
A ResourceLoader interface is used to resolve templateUrls to template
strings and can return results either synchronously or asynchronously.
During sync compilation it is an error if the ResourceLoader returns a
Promise.
Two ResourceLoader implementations are provided. One uses 'fs' to read
resources directly from disk and is chosen if the CompilerHost doesn't
provide a readResource method. The other wraps the readResource method
from CompilerHost if it's provided.
PR Close#24704
