These token interfaces will make it easier to reason about tokens in the
parser and in specs.
Previously, it was never clear what items could appear in the `parts`
array of a token given a particular `TokenType`. Now, each token interface
declares a labelled tuple for the parts, which helps to document the token
better.
PR Close#42062
The tests were checking that the source-span of parsed HTML nodes were
accurate, but they were not checking the span when it includes the
"leading trivia", which are given by the `fullStart` rather than `start`
location.
PR Close#42062
When it was tokenized, text content is split into parts that can include
interpolations and encoded entities tokens.
To make this information available to downstream processing, this commit
adds these tokens to the `Text` AST nodes, with suitable processing.
PR Close#42062
The lexer now splits interpolation tokens out from attribute value tokens.
Previously the attribute value of `<div attr="Hello, {{ name}}">` would be a single
token. Now it will be three tokens:
```
ATTR_VALUE_TEXT: "Hello, "
ATTR_VALUE_INTERPOLATION: "{{", " name", "}}"
ATTR_VALUE_TEXT: ""
```
- ATTR_VALUE_INTERPOLATION tokens have three parts, "start marker",
"expression" and "end marker".
- ATTR_VALUE_INTERPOLATION tokens are always preceded and followed
by TEXT tokens, even if they represent an empty string.
The HTML parser has been modified to recombine these tokens to allow this
refactoring to have limited effect in this commit. Further refactorings
to use these new tokens will follow in subsequent commits.
PR Close#42062
The lexer now splits interpolation tokens out from text tokens.
Previously the contents of `<div>Hello, {{ name}}<div>` would be a single
text token. Now it will be three tokens:
```
TEXT: "Hello, "
INTERPOLATION: "{{", " name", "}}"
TEXT: ""
```
- INTERPOLATION tokens have three parts, "start marker", "expression"
and "end marker".
- INTERPOLATION tokens are always preceded and followed by TEXT tokens,
even if they represent an empty string.
The HTML parser has been modified to recombine these tokens to allow this
refactoring to have limited effect in this commit. Further refactorings
to use these new tokens will follow in subsequent commits.
PR Close#42062
This commit updates the parser logic to continue to try to match an end
tag to an unclosed open tag on the stack. Previously, it would only
push an error to the list and stop looking at unclosed elements.
For example, the invalid HTML of `<li><div></li>`, has an unclosed
element stack of [`li`, `div`] when it encounters the close `li` tag.
We compare against the previously unclosed tag `div` and see that this is
unexpected. Instead of simply giving up here, we continue to move up the
unclosed tags until we find a match (if there is one).
PR Close#42554
If the template parse option `leadingTriviaChars` is configured to
consider whitespace as trivia, any trailing whitespace of an element
would be considered as leading trivia of the subsequent element, such
that its `start` span would start _after_ the whitespace. This means
that the start span cannot be used to mark the end of the current
element, as its trailing whitespace would then be included in its span.
Instead, the full start of the subsequent element should be used.
To harden the tests that for the Ivy parser, the test utility `parseR3`
has been adjusted to use the same configuration for `leadingTriviaChars`
as would be the case in its production counterpart `parseTemplate`. This
uncovered another bug in offset handling of the interpolation parser,
where the absolute offset was computed from the start source span
(which excludes leading trivia) whereas the interpolation expression
would include the leading trivia. As such, the absolute offset now also
uses the full start span.
Fixes#39148
PR Close#40513
Let's say we have a code like
```html
<div<span>123</span>
```
Currently this gets parsed into a tree with the element tag `div<span`.
This has at least two downsides:
- An incorrect diagnostic that `</span>` doesn't close an element is
emitted.
- A consumer of the parse tree using it for editor services is unable to
provide correct completions for the opening `<span>` tag.
This patch attempts to fix both issues by instead parsing the code into
the same tree that would be parsed for `<div></div><span>123</span>`.
In particular, we do this by optimistically scanning an open tag as
usual, but if we do not notice a terminating '>', we mark the tag as
"incomplete". A parser then emits an error for the incomplete tag and
adds a synthetic (recovered) element node to the tree with the
incomplete open tag's name.
What's the downside of this? For one, a breaking change.
<ol>
<li>
The first breaking change is that `<` symbols that are ambiguously text
or opening tags will be parsed as opening tags instead of text in
element bodies. Take the code
```html
<p>a<b</p>
```
Clearly we cannot have the best of both worlds, and this patch chooses
to swap the parsing strategy to support the new feature. Of course, `<`
can still be inserted as text via the `<` entity.
</li>
</ol>
Part of #38596
PR Close#38681
Previously, the `sourceSpan` and `startSourceSpan` were the same
object, which meant that you had the following situation:
```
element = <div>some content</div>
sourceSpan = <div>
startSourceSpan = <div>
endSourceSpan = </div>
```
This made `sourceSpan` redundant and meant that if you
wanted a span for the whole element including its content
and closing tag, it had to be computed.
Now `sourceSpan` is separated from `startSourceSpan`
resulting in:
```
element = <div>some content</div>
sourceSpan = <div>some content</div>
startSourceSpan = <div>
endSourceSpan = </div>
```
PR Close#38581
Previously, the `startSourceSpan` property could be null
but in reality it is always well defined - except for a legacy
case in the old i18n extraction/merging code, where the
typings for source-spans are already being undermined.
Making this property non-null, simplifies code elsewhere
in the project.
PR Close#38581
Previously the lexer was responsible for deciding whether an "inline"
template should also have its line-endings normalized.
Now this decision is made higher up in the call stack to allow more
flexibility in the parser/lexer.
PR Close#38581
HTML is very lenient when it comes to closing elements, so Angular's parser has
rules that specify which elements are implicitly closed when closing a tag.
The parser keeps track of the nesting of tag names using a stack and parsing
a closing tag will pop as many elements off the stack as possible, provided
that the elements can be implicitly closed.
For example, consider the following templates:
- `<div><br></div>`, the `<br>` is implicitly closed when parsing `</div>`,
because `<br>` is a void element.
- `<div><p></div>`, the `<p>` is implicitly closed when parsing `</div>`,
as `<p>` is allowed to be closed by the closing of its parent element.
- `<ul><li>A <li>B</ul>`, the first `<li>` is implicitly closed when parsing
the second `<li>`, whereas the second `<li>` would be implicitly closed when
parsing the `</ul>`.
In all the cases above the parsed structure would be correct, however the source
span of the closing `</div>` would incorrectly be assigned to the element that
is implicitly closed. The problem was that closing an element would associate
the source span with the element at the top of the stack, however this may not
be the element that is actually being closed if some elements would be
implicitly closed.
This commit fixes the issue by assigning the end source span with the element
on the stack that is actually being closed. Any implicitly closed elements that
are popped off the stack will not be assigned an end source span, as the
implicit closing implies that no ending element is present.
Note that there is a difference between self-closed elements such as `<input/>`
and implicitly closed elements such as `<input>`. The former does have an end
source span (identical to its start source span) whereas the latter does not.
Fixes#36118
Resolves FW-2004
PR Close#38126
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
Previously, an expansion case could only start with an alpha numeric character.
This commit fixes this by allowing an expansion case to start with any character
except `}`.
The [ICU spec](http://userguide.icu-project.org/formatparse/messages) is pretty vague:
> Use a "select" argument to select sub-messages via a fixed set of keywords.
It does not specify what can be a "keyword" but from looking at the surrounding syntax it
appears that it can indeed be any string that does not contain a `}` character.
Closes#31586
PR Close#36123
BREAKING CHANGE:
Certain elements (like `<tr>` or `<col>`) require parent elements to be of a certain type by the HTML specification
(ex. <tr> can only be inside <tbody> / <thead>). Before this change Angular template parser was auto-correcting
"invalid" HTML using the following rules:
- `<tr>` would be wrapped in `<tbody>` if not inside `<tbody>`, `<tfoot>` or `<thead>`;
- `<col>` would be wrapped in `<colgroup>` if not inside `<colgroup>`.
This meachanism of automatic wrapping / auto-correcting was problematic for several reasons:
- it is non-obvious and arbitrary (ex. there are more HTML elements that has rules for parent type);
- it is incorrect for cases where `<tr>` / `<col>` are at the root of a component's content, ex.:
```html
<projecting-tr-inside-tbody>
<tr>...</tr>
</projecting-tr-inside-tbody>
```
In the above example the `<projecting-tr-inside-tbody>` component culd be "surprised" to see additional
`<tbody>` elements inserted by Angular HTML parser.
PR Close#29219
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
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
BREAKING CHANGE:
The `<template>` tag was deprecated in Angular v4 to avoid collisions (i.e. when
using Web Components).
This commit removes support for `<template>`. `<ng-template>` should be used
instead.
BEFORE:
<!-- html template -->
<template>some template content</template>
# tsconfig.json
{
# ...
"angularCompilerOptions": {
# ...
# This option is no more supported and will have no effect
"enableLegacyTemplate": [true|false]
}
}
AFTER:
<!-- html template -->
<ng-template>some template content</ng-template>
PR Close#22783
