The `urltransform` option allows to redirect a non-blocked network
request to another URL. There are restrictions on its usage:
- require a trusted source -- thus uBO-maintained lists or user
filters
- the `urltransform` value must start with a `/`
If at least one of these conditions is not fulfilled, the filter
will be invalid and rejected.
The requirement to start with `/` is to enforce that only the path
part of a URL can be modified, thus ensuring the network request
is redirected to the same scheme and authority (as defined at
https://en.wikipedia.org/wiki/Uniform_Resource_Identifier#Syntax).
Usage example (redirect requests for CSS resources to a non-existing
resource, for demonstration purpose):
||iana.org^$css,urltransform=/notfound.css
Name of this option is inspired from DNR API:
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/declarativeNetRequest/URLTransform
This commit required to bring the concept of "trusted source" to
the static network filtering engine.
Additionally:
Use `export UBO_VERSION=local` at the console to build MV3 extension using
current version of uBO code base. By default, the version is taken from
`./platform/mv3/ubo-version' and usually set to last stable release.
Since in uBOL filter lists from various sources are combined into
a single list, there must be a way to turn on/off trust level
inside the resulting combined filter list so as to be able to
validate the trust level of filters requiring trust.
This commit adds new parser directives understood only by MV3
compiler to turn on/off trust flag internally.
Related issues:
- https://github.com/uBlockOrigin/uBOL-issues/issues/5#issuecomment-1575425913
- https://github.com/w3c/webextensions/issues/403
Currently, there is no other way to inject CSS user styles than to
wake up the service worker, so that it can inject the CSS styles
itself using the `scripting.insertCSS()` method.
If ever the MV3 API supports injecting CSS user styles directly
from a content script, uBOL will be back to be fully declarative.
At this point the service worker is very lightweight since the
filtering is completely declarative, so this is not too much of
an issue performance-wise except for the fact that waking up the
service worker for the sole purpose of injecting CSS user styles
and nothing else introduces a pointless overhead.
Hopefully the MV3 API will mature to address such inefficiency.
Source code of scriplets is now fetched directly from uBO
project, so there is no longer the need to keep duplicate
versions of scriplet code.
All scriplet filters are now supported.
Raymond Hill