A couple tests were already passing, and just needed to be enabled. This includes tests pertaining to:
* ng-template
* host binding styling slots
* and host animation bindings
* some literal tests (which were missing some $foo$ escaped names)
We add pipeline-specific versions of the following tests, and enable them:
* A local refs test. The consts for the element attributes and the consts for local reference are collected in the reverse order, but the emitted template is functionally the same.
* A safe accesstest. Consider the expression `$any(val)?.foo`. `TemplateDefinitionBuilder` extracts a temporary variable: `($tmp_0_0$ = $ctx$.val) == null ? null : $tmp_0_0$.foo`. It presumably does this because it considers the `$any(...)` to be a function call. However, this is not a real call, so Template Pipeline safely ignores it and declines to generate a temporary.
* Another local refs test. AttributeMarker.Template is emitted at the end of the const array (instead of the middle)
PR Close#51950
Consider an `ng-template` which is generated as a result of a structural directive:
```
<div *ngFor="let inner of items"
(click)="onClick(inner)"
[title]="getTitle()"
>
```
This should logically expand into something like the following:
```
<ng-template [ngForOf]="..." >
<div (click)="..." [title]="..."></div>
</ng-template>
```
Note that the `(click)` handler and the `[title]` property are only present on the inner div, *not* on the enclosing generated `ng-template`.
Previously, Template Pipeline would place these bindings on *both* the tempate and the inner element.
However, we can't just remove them completely, because these bindings should still be matchable on the generated `ng-template` (which is very surprising, but nonetheless true).
We resolve this issue with two improvements:
(1) The ingestion step is now much smarter about determining not only if a binding is on a template element, but whether it actually targets that template element.
(2) We use `ExtractedAttributeOp` directly, rather than going through `BindingOp`, to cause the `ng-template` to still receive these bindings in its `consts` array for matching purposes.
PR Close#51950
For components, the parser already extracts the `important` property (and it is later disregarded). However, because host bindings use a totally separate parsing code path, this was never happing for host bindings.
Here, we add some code to the host style parsing phase to drop the `!important` suffix.
We could solve this category of problems for good by parsing host bindings with the same code as template bindings.
PR Close#51950
Previously, we always generated temporary variable declarations at the beginning of each view's update block. This is wrong, for two reasons:
1. Temporaries can be used in the create block
2. When listeners use temporaries, we should declare them inside the listener.
Now, we always place temporaries at the beginning of the enclosing OpList, and recursively try to generate them when we find a listener.
PR Close#51950
Reworks a few more places to output arrow functions instead of function declarations in order to reduce the amount of code we generate. Some of these places include:
* Factories in injectable definitions.
* Forward references.
* `dependencies` function in the component definition.
* `consts` function in the component definition.
PR Close#52010
The template pipeline now supports basic forms of `defer` blocks. This includes the `loading`, `placeholder`, and `error` blocks, as well as the loading and placeholder configuration options.
Lazy dependencies and prefetch are not yet implemented.
PR Close#51942
Enables the new `@` block syntax by default by removing the `enabledBlockTypes` flags. There are still some internal flags that allow special use cases to opt out of the block syntax, like during XML parsing and when compiling older libraries (see #51979).
PR Close#51994
Increases the `minVersion` of component declarations that use bloks to v17 in order to indicate to users that they need to update if the library they're using is on the new syntax, while preserving backwards compatibility for libraries that do not use the syntax.
PR Close#51979
We were previously emitting pure functions as `function foo(args) {return bar;}`, but `TemplateDefinitionBuilder` uses arrow functions instead (`const foo = (args) => bar`). By matching this behavior, we can enable many additional tests.
PR Close#51961
This is a deceptively simple fix for a deep issue. Consider the following template:
```
<button [title]="myTitle" [id]="(auth().identity() | async)" [tabindex]="1">
```
`TemplateDefinitionBuilder` allocates the following variable (binding) slots:
v[0] = [title] binding
v[1] = [id] binding
v[2] = [tabindex] binding
v[3] = pipe binding
v[4] = pipe binding
As you can see, all three top-level property bindings were assigned variable indices. Then, variables for nested expressions were assigned.
Before this change, Template Pipeline would choose the following order:
v[0] = [title] binding
v[1] = [id] binding
v[2] = pipe binding
v[3] = pipe binding
v[4] = [tabindex] binding
With this order, nested expressions have their variables counted and assigned before subsequent top-level property bindings. This results in different variable indices for `pipeBinding` expressions that are not inside the final property binding.
However, this is not just different -- it's actually incorrect! Consider a case like the following:
```
<button [p1]="c ? (a | pipe) : 3" [p2]="b | pipe">
```
These pipe bindings are executed *conditionally*. This means that, because we don't count and assign all the "fixed" variable slots first, i.e. those belonging to the property bindings, their indices might end up incorrect, depending on whether or not a pipeBinding happened as part of the update block.
With this change, we count all variables on top-level ops first, and then descend into all expressions.
PR Close#51961
An `if` block can specify an alias for its main expression. We now support these in the template pipeline:
- We generate a temporary variable for the original expression
- We pass the temporary to the `conditional` instruction's context argument
- We provide the alias's name in the ambient context variables map
The context variables map now also accepts a name whose lookup value on the context object is empty. This will be interpreted as a read of the entire context object.
PR Close#51931
This entails adding a bit of extra logic to the existing conditional ingestion and corresponding phase, because `if` blocks lack a test expression.
Additionally, enable a couple more `switch` tests by resolving a curious issue -- we now consume a variable for conditionals.
PR Close#51931
Adds support for i18n expressions in i18n messages, and allows i18n
messages on templates.
Co-authored-by: Alex Rickabaugh <alxhub@users.noreply.github.com>
Co-authored-by: Dylan Hunn <dylhunn@users.noreply.github.com>
PR Close#51876
Adds support for defining `viewport`, `interaction` and `hover` triggers with no parameters. If the framework encounters such a case, it resolves the trigger to the root element of the `@placeholder` block. Triggers with no parameters have the following restrictions:
1. They have to be placed on an `@defer` block that has an `@placeholder`.
2. The `@placeholder` can only have one root node.
3. The root placeholder node has to be an element.
PR Close#51922
Changes `TemplateDefinitionBuilder` to output i18n message parameters in
sorted order to make it easier for the template pipeline to generate
identical output. This does not result in any functional change, but
will make it much easier to shared output golden files with the template
pipeline.
PR Close#51911
Fixes that we were allocating slots for the expressions of `if`, `else if`, `switch` and `case` blocks which we weren't using for anything.
PR Close#51913
Switches the syntax for blocks from `{#block}{/block}` to `@block {}` based on the feedback from the community.
Read more about the decision-making process in our blog: https://blog.angular.io/meet-angulars-new-control-flow-a02c6eee7843
The existing block types changed in the following ways:
**Conditional blocks:**
```html
<!-- Before -->
{#if cond}
Main content
{:else if otherCond}
Else if content
{:else}
Else content
{/if}
<!-- After -->
@if (cond) {
Main content
} @else if (otherCond) {
Else if content
} @else {
Else content
}
```
**Deferred blocks**
```html
<!-- Before -->
{#defer when isLoaded}
Main content
{:loading} Loading...
{:placeholder} <icon>pending</icon>
{:error} Failed to load
{/defer}
<!-- After -->
@defer (when isLoaded) {
Main content
} @loading {
Loading...
} @placeholder {
<icon>pending</icon>
} @error {
Failed to load
}
```
**Switch blocks:**
```html
<!-- Before -->
{#switch value}
{:case 1}
One
{:case 2}
Two
{:default}
Default
{/switch}
<!-- After -->
@switch (value) {
@case (1) {
One
}
@case (2) {
Two
}
@default {
Default
}
}
```
**For loops**
```html
<!-- Before -->
{#for item of items; track item}
{{item.name}}
{:empty} No items
{/for}
<!-- After -->
@for (item of items; track item) {
{{item.name}}
} @empty {
No items
}
```
PR Close#51891
Reworks the `setClassMetadata` calls to generate arrow functions instead of full anonymous function declarations. While this won't have an effect on production bundle sizes, it's easier to read and it should lead to small parsing time gains in dev mode.
PR Close#51637
Adds support for `on viewport` and `prefetch on viewport` triggers which will load the deferred content when the element comes into the view.
PR Close#51874
Adds support for `on hover` and `prefetch on hover` triggers. Some code had to be moved around so it could be reused from the `on interaction` triggers.
PR Close#51874
Updates the logic that generates the instructions for the `on interaction` and `prefetch on interaction` triggers to their final shape. Now the instructions take two arguments:
1. `triggerIndex` - index at which to find the trigger in the view where it will be rendered.
2. `walkUpTimes` - tells the runtime how many views up it needs to go to find the trigger element. If the argument is omitted, it means that the trigger is in the same view as the deferred block. A positive number means that the runtime needs to go up X amount of times to find the trigger. A negative number means that the trigger is inside the root view of the placeholder block. Negative numbers are capped at -1 since the placeholder is always in the same position at runtime.
PR Close#51830
Adds support for template type checking inside `for` blocks. It is implemented by generating a JS `for...of` statement inside the TCB. The various loop variables (e.g. `$index`) are implemented by declaring a local number variable.
PR Close#51690
Adds support for template type checking inside `if` blocks. It is implemented by generating a JS `if` statement inside the TCB which allows us to do type narrowing of the expression. The `as` parameter is implemented by declaring a variable inside the `if` statement.
PR Close#51690
Adds support for template type checking inside `switch` blocks. It is implemented by generating a JS `switch` statement inside the TCB which allows us to do type narrowing of the expression.
PR Close#51690
Content project allows the content to specify its own selector for matching against content projection slots, using the `ngProjectAs` special attribute. We can now treat this attribue specially, and generate the appropriate flag in the consts array, followed by the parsed CSS selector.
PR Close#51544
Supporting content projection requires us to emit three new kinds of output:
1. An `ngContentSelectors` field on the component metadata, which points to an array in the constant pool with all of the `select` attributes from `<ng-content>` elements.
2. One `projectionDef` instruction at the beginning of each root view template function for a component. That `projectionDef` points to a constant pool expression, which contains *parsed* selectors for all `<ng-content>` elements in the root's entire view tree.
3. A `projection` instruction for each `<ng-content>` slot in the view tree. These each get a data slot, a monotonically increasing "content slot", and a pointer to the tag's attributes in the component const array.
We support the first two features entirely within a new compilation phase.
The third feature, collection of processed attributes, is a bit trickier. We now treat `<ng-content>` tags as element-like ops, and use the normal attribute ingestion pipeline to process any attributes, and assign the appropriate `ConstIndex`.
**Note**: We also split up a number of the tests into two expectations files, one for the view functions, and one for other const listerals from the constant pool. This is because `TemplateDefinitionBuilder` emits the literals in a quirky order (mixed in with the view functions) due to how it lazily generates view functions. Our eager ordering is totally different, but by splitting the expectations, we can still share the same tests with `TemplateDefinitionBuilder`.
PR Close#51544
The `verifyPlaceholdersIntegrity` check in the compliance tests was basically a noop, because it was returning false inside a `forEach` callback. Fixing it revealed that it had fallen out of date, because one of the regexes it uses was incorrect. The problem is that it assumed the placeholder keys would always be string literals, however it's possible that they're identifiers. These changes resolve the issue by not looking at the keys at all since we don't do anything with them.
PR Close#51751
Currently internally Angular has some customized tsconfig files, because we don't align with the tsconfig of the rest of g3. These changes enable `noImplicitReturns` and `noPropertyAccessFromIndexSignature` to align better with the internal config.
PR Close#51728
Reworks the pure functions to use arrow functions with an implicit return instead of function expressions. This allows us to shave off some bytes for each pure function, because we can avoid some of the syntax.
PR Close#51668
These changes build on top of #51514 to add support for advanced expressions inside the `track` parameter of `for` loop blocks. There are two different outputs that the compiler can generate:
1. If the tracking function only references the item or `$index`, the compiler generates a pure arrow function as a constant references in the `repeaterCreate` instruction.
2. If the tracking function has references to properties outside of the `for` loop block, the compiler will rewrite those references to go through `this` and generate a function declaration. The runtime will `bind` the declaration to the current component instance so that the rewritten `this` references are resolved correctly.
Advanced tracking expression come with the following limitations to ensure the best possible performance:
1. They can only reference the item, `$index` and properties directly on the component instance. This means that there'll be an error when accessing this like local template variables and references. While we could get this to work, we would have to traverse the context tree at runtime which will degrade the performance of the loop, because it's a linear time operation that is performed on each comparison. Furthermore, allowing local references would require us re-evaluate the list when any one of them has changed.
2. Pipes aren't allowed inside the tracking function.
3. Object literals and pipes used inside the tracking expression will be recreated on each invocation.
PR Close#51618
Adds type checking for the contents of `if`, `switch` and `for` blocks.
**Note:** this is just an initial implementation to get some basic type checking working and to figure out the testing setup. We'll need special TCB structures for this syntax so that we can support type narrowing.
PR Close#51570
With the new control flow and defer blocks it'll be common for several template instructions to be declare one after another. These changes add support for chaining to the `template` instruction which will allow us to save some bytes.
PR Close#51546
Adds the initial implementation to generate the instructions for the `for` loop block.
**Note:** the expressions we support in the `track` paramateter are currently limited to tracking by identity or index, or a specific property of the item. Supporting more advanced expression will require additional work that I'll do in a follow-up PR.
PR Close#51514
`switch` blocks are part of the new control flow syntax. This commit adds support for processing them, and emitting the appropriate templates and conditional instructions.
PR Close#51518
`syntheticHostListener` and `listener` have ordering dependencies. We reuse the existing ordering phase, and generalize it to also order create mode instructions.
PR Close#51498
