Currently the compiler treats `@page` rules in the same way as `@media`, however that is incorrect and it results in invalid CSS, because `@page` allows style declarations at the root (e.g. `@page (margin: 50%) {}`) and it only allows a limited set of at-rules to be nested into it. Given these restrictions, we can't really encapsulate the styles since they apply at the document level when the user tries to print.
These changes make it so that `@page` rules are preserved so that we don't break the user's CSS.
More information: https://www.w3.org/TR/css-page-3Fixes#26269.
PR Close#41915
`@font-face` rules cannot contain nested selectors. Nor can they be
nested under a selector. Normally this would be a syntax error by the
author of the styles. But in some rare cases, such as importing styles
from a library, and applying `:host ::ng-deep` to the imported styles,
we can end up with broken css if the imported styles happen to contain
`@font-face` rules.
This commit works around this problem by sanitizing such cases (erasing
any scoping selectors) during emulated ShadowDOM encapsulation style
processing.
Fixes#41751
PR Close#41815
When there was more than one rule in a single style string, only the first
rule was having its `:host` selector processed correctly. Now subsequent
rules will also be processed accurately.
Fixes#41237
PR Close#41261
The previous commits refactored the `ShadowCss` emulator to support
desirable use-cases of `:host-context()`, but it dropped support
for passing a comma separated list of selectors to the `:host-context()` .
This commit rectifies that omission, despite the use-case not being
valid according to the ShadowDOM spec, to ensure backward compatibility
with the previous implementation.
PR Close#40494
In `ViewEncapsulation.Emulated` mode the compiler converts `:host` and
`:host-context` pseudo classes into new CSS selectors.
Previously, when there was both `:host-context` and `:host` classes in a
selector, the compiler was generating incorrect selectors. There are two
scenarios:
* Both classes are on the same element (i.e. not separated). E.g.
`:host-context(.foo):host(.bar)`. This setup should only match the
host element if it has both `foo` and `bar` classes. So the generated
CSS selector should be: `.foo.bar<hostmarker>`.
* The `:host` class is on a descendant of the `:host-context`. E.g.
`:host-context(.foo) :host(.bar)`. This setup should only match the
`.foo` selector if it is a proper ancestor of the host (and not on the
host itself). So the generated CSS selector should be:
`.foo .bar<hostmarker>`.
This commit fixes the generation to handle these scenarios.
Fixes#14349
PR Close#40494
In `ViewEncapsulation.Emulated` mode, the compiler must generate additional
combinations of selectors to handle the `:host-context()` pseudo-class function.
Previously, when there is was more than one `:host-context()` selector in a
rule, the compiler was generating invalid selectors.
This commit generates all possible combinations of selectors needed to
match the same elements as the native `:host-context()` selector.
Fixes#19199
PR Close#40494
In `ViewEncapsulation.Emulated` mode, the compiler must generate additional
combinations of selectors to handle the `:host-context()` pseudo-class function.
Previously, when there is was more than one `:host-context()` selector in a
rule, the compiler was generating invalid selectors.
This commit generates all possible combinations of selectors needed to
match the same elements as the native `:host-context()` selector.
Fixes#19199
PR Close#40494
CSS supports escaping in selectors, e.g. writing `.foo:bar` will match an element with the
`foo` class and `bar` pseudo-class, but `.foo\:bar` will match the `foo:bar` class. Our
shimmed shadow DOM encapsulation always assumes that `:` means a pseudo selector
which breaks a selector like `.foo\:bar`.
These changes add some extra logic so that escaped characters in selectors are preserved.
Fixes#31844.
PR Close#40264
At a high level, the current shadow DOM shim logic works by escaping the content of a CSS rule
(e.g. `div {color: red;}` becomes `div {%BLOCK%}`), using a regex to parse out things like the
selector and the rule body, and then re-adding the content after the selector has been modified.
The problem is that the regex has to be very broad in order capture all of the different use cases,
which can cause it to match strings suffixed with a semi-colon in some places where it shouldn't,
like this URL from Google Fonts `https://fonts.googleapis.com/css2?family=Roboto:wght@400;500&display=swap`.
Most of the time this is fine, because the logic that escapes the rule content to `%BLOCK%` will
have converted it to something that won't be matched by the regex. However, it breaks down for rules
like `@import` which don't have a body, but can still have quoted content with characters that can
match the regex.
These changes resolve the issue by making a second pass over the escaped string and replacing all
of the remaining quoted content with `%QUOTED%` before parsing it with the regex. Once everything
has been processed, we make a final pass where we restore the quoted content.
In a previous iteration of this PR, I went with a shorter approach which narrowed down the
regex so that it doesn't capture rules without a body. It fixed the issue, but it also ended
up breaking some of the more contrived unit test cases. I decided not to pursue it further, because
we would've ended up with a very long and brittle regex that likely would've broken in even weirder
ways.
Fixes#38587.
PR Close#38716
Currently, `shimCssText` only keep `/*# sourceMappingUrl ... */` comments and strip `/*# sourceURL ... */` comments. So, Chrome can't find the source maps for component style(that's created in new `style` tags)
PR Close#16088
`cmp:host {}` and `cmp:host some-other-selector {}` were not handled
consistently.
Note those should not match anything but are made equivalent to respectively
`:host(cmp)` and `:host(cmp) some-other-selector` to avoid breaking legacy apps.
- /deep/ is deprecated and being removed from Chrome
- >>> is semantically invalid in a stylesheet
- sass will no longer support either in any version of sass
-> use ::ng-deep in emulated shadow DOM mode
Because the deep combinator is deprecated in the CSS spec,
`/deep/`, `>>>` and `::ng-deep` are also deprecated in emulated shadow DOM mode
and will be removed in the future.
see https://www.chromestatus.com/features/6750456638341120
Kristiyan Kostadinov
Pete Bacon Darwin
Jessica Janiuk
Joey Perrott
Alex Rickabaugh
Zhicheng Wang
Misko Hevery
Victor Berchet
Jason Aden