The html parser already normalizes line endings (converting `\r\n` to `\n`)
for most text in templates but it was missing the expressions of ICU expansions.
In ViewEngine backticked literal strings, used to define inline templates,
were already normalized by the TypeScript parser.
In Ivy we are parsing the raw text of the source file directly so the line
endings need to be manually normalized.
This change ensures that inline templates have the line endings of ICU
expression normalized correctly, which matches the ViewEngine.
In ViewEngine external templates, defined in HTML files, the behavior was
different, since TypeScript was not normalizing the line endings.
Specifically, ICU expansion "expressions" are not being normalized.
This is a problem because it means that i18n message ids can be different on
different machines that are setup with different line ending handling,
or if the developer moves a template from inline to external or vice versa.
The goal is always to normalize line endings, whether inline or external.
But this would be a breaking change since it would change i18n message ids
that have been previously computed. Therefore this commit aligns the ivy
template parsing to have the same "buggy" behavior for external templates.
There is now a compiler option `i18nNormalizeLineEndingsInICUs`, which
if set to `true` will ensure the correct non-buggy behavior. For the time
being this option defaults to `false` to ensure backward compatibility while
allowing opt-in to the desired behavior. This option's default will be
flipped in a future breaking change release.
Further, when this option is set to `false`, any ICU expression tokens,
which have not been normalized, are added to the `ParseResult` from the
`HtmlParser.parse()` method. In the future, this collection of tokens could
be used to diagnose and encourage developers to migrate their i18n message
ids. See FW-2106.
Closes#36725
PR Close#36741
Similar to interpolation, we do not want to completely remove whitespace
nodes that are siblings of an expansion.
For example, the following template
```html
<div>
<strong>items left<strong> {count, plural, =1 {item} other {items}}
</div>
```
was being collapsed to
```html
<div><strong>items left<strong>{count, plural, =1 {item} other {items}}</div>
```
which results in the text looking like
```
items left4
```
instead it should be collapsed to
```html
<div><strong>items left<strong> {count, plural, =1 {item} other {items}}</div>
```
which results in the text looking like
```
items left 4
```
---
**Analysis of the code and manual testing has shown that this does not cause
the generated ids to change, so there is no breaking change here.**
PR Close#31962
Leading trivia, such as whitespace or comments, is
confusing for developers looking at source-mapped
templates, since they expect the source-map segment
to start after the trivia.
This commit adds skipping trivial characters to the lexer;
and then implements that in the template parser.
PR Close#30095
This PR alligns markup language lexer with the previous behaviour in version 7.x:
https://stackblitz.com/edit/angular-iancj2
While this behaviour is not perfect (we should be giving users an error message
here about invalid HTML instead of assuming text node) this is probably best we
can do without more substential re-write of lexing / parsing infrastructure.
This PR just fixes#29231 and restores VE behaviour - a more elaborate fix will
be done in a separate PR as it requries non-trivial rewrites.
PR Close#29328
This PR alligns markup language lexer with the previous behaviour in version 7.x:
https://stackblitz.com/edit/angular-iancj2
While this behaviour is not perfect (we should be giving users an error message
here about invalid HTML instead of assuming text node) this is probably best we
can do without more substential re-write of lexing / parsing infrastructure.
This PR just fixes#29231 and restores VE behaviour - a more elaborate fix will
be done in a separate PR as it requries non-trivial rewrites.
PR Close#29328
Previously the start of a character indicated by an escape sequence
was being incorrectly computed by the lexer, which caused tokens
to include the start of the escaped character sequence in the
preceding token. In particular this affected the name extracted
from opening tags if the name was terminated by an escape sequence.
For example, `<t\n>` would have the name `t\` rather than `t`.
This fix refactors the lexer to use a "cursor" object to iterate over
the characters in the template source. There are two cursor implementations,
one expects a simple string, the other expects a string that contains
JavaScript escape sequences that need to be unescaped.
PR Close#28978
The parts of a token are supposed to be an array of not-null strings,
but we were using `null` for tags that had no prefix. This has been
fixed to use the empty string in such cases, which allows the `null !`
hack to be removed.
PR Close#28978
When tokenizing markup (e.g. HTML) element attributes
can have quoted or unquoted values (e.g. `a=b` or `a="b"`).
The `ATTR_VALUE` tokens were capturing the quotes, which
was inconsistent and also affected source-mapping.
Now the tokenizer captures additional `ATTR_QUOTE` tokens,
which the HTML related parsers understand and factor into their
token parsing.
PR Close#28055
In order to support source mapping of templates, we need
to be able to tokenize the template in its original context.
When the template is defined inline as a JavaScript string
in a TS/JS source file, the tokenizer must be able to handle
string escape sequences, such as `\n` and `\"` as they
appear in the original source file.
This commit teaches the lexer how to unescape these
sequences, but only when the `escapedString` option is
set to true. Otherwise there is no change to the tokenizing
behaviour.
PR Close#28055
The lexer that does the tokenizing can now process only a part the source
string, by passing a `range` property in the `options` argument. The
locations of the nodes that are tokenized will now take into account the
position of the span in the context of the original source string.
This `range` option is, in turn, exposed from the template parser as well.
Being able to process parts of files helps to enable SourceMap support
when compiling inline component templates.
PR Close#28055
This commit consolidates the options that can modify the
parsing of text (e.g. HTML, Angular templates, CSS, i18n)
into an AST for further processing into a single `options`
hash.
This makes the code cleaner and more readable, but also
enables us to support further options to parsing without
triggering wide ranging changes to code that should not
be affected by these new options. Specifically, it will let
us pass information about the placement of a template
that is being parsed in its containing file, which is essential
for accurate SourceMap processing.
PR Close#28055
Pete Bacon Darwin
Alex Rickabaugh
Pawel Kozlowski
Matias Niemelä
Misko Hevery
Jason Aden