Currently the field changeDetection undergoes some static analysis to check if it is `ChangeDetectionStrategy` enum. Such static check fails in local compilation mode in g3 as the symbol cannot be resolved. So in local compilation mode we bypass such resolving and just write the expression as is into the component definition.
PR Close#51848
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
Reworks the compiler to use the API introduced in #51816 to match triggers to the element nodes they point to. This will be used to generate the new instructions for `on interaction` and `prefetch on interaction`.
PR Close#51830
Adds support for template type checking of the `track` expression of a `for` loop block. Tracking expressions are treated as any other expression for type checking, however we have some special validation that doesn't allow them to access template variables and local references.
PR Close#51690
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
Adds a utility to the `BoundTarget` that helps with resolving which element a deferred block is pointing to. We need a separate method for this, because deferred blocks have some special logic for where the trigger can be located.
PR Close#51816
When the `TargetBinder` was written, the only embedded-view-based nodes were templates, but now we have `{#if}`, `{#switch}` and `{#defer}` which have similar semantics. These changes rework the binder to account for the new nodes.
PR Close#51816
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 new built-in control flow design includes calls to the `template` instruction with fewer arguments. This was previously handled implicitly, but it's more extensible to add an explicit flag to the template op to handle this case.
PR Close#51544
Today in local compilation mode the NgModule bootstrap definition is moved as it is into the runtime `ɵɵdefineNgModule`. This runtime was initially made for AoT full compilation mode and assumes that the bootstrap info is already flattened and resolved. This is not the case in local compilation where the bootstrap is the raw expression coming from the NgModule decorator and can be a nested array. To get around this problem we move the bootstrap along with other scope info (e.g., declarations, imports, exports) to the runtime`ɵɵsetNgModuleScope` to be further analyzed and flattened in runtime.
PR Close#51767
BREAKING CHANGE: Node.js v16 support has been removed and the minimum support version has been bumped to 18.13.0.
Node.js v16 is planned to be End-of-Life on 2023-09-11. Angular will stop supporting Node.js v16 in Angular v17. For Node.js release schedule details, please see: https://github.com/nodejs/release#release-schedule
PR Close#51755
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
To further modernize and improve the performance of the i18n digest generation,
The 64-bit aspects of the process now use the native `BigInt` instead of a
custom JavaScript implementation. This removes the need for the big_integer
helper code and associated tests as the code was not used anywhere else in the
framework. Only the `BigInt` constructor, `BigInt.asUintN` function, and
`.toString` function are currently used. `BigInt` literals can unfortunately
not yet be used due to the bazel test devmode setup which compiles the TypeScript
code at an EcmaScript level that does not yet support the literals.
Browser support information:
- BigInt constructor: https://caniuse.com/mdn-javascript_builtins_bigint_bigint
- BigInt asUintN: https://caniuse.com/mdn-javascript_builtins_bigint_asuintn
- BigInt toString: https://caniuse.com/mdn-javascript_builtins_bigint_tostring
PR Close#48321
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 an instruction that allows us to access the containing component instance directly instead of having to traverse the context tree. This will be necessary for the tracking function of `for` loop blocks.
PR Close#51618
When `preserveWhitespaces` is enabled, `switch` blocks can end up with content inside their main block due to the indentation that is usually used for the nested cases. This was tripping up the validation that doesn't allow content inside the main block of `switch`.
These changes update the validation to ignore empty text nodes.
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
Component compilation and host binding compilation previously used separate compilation emit functions. This was a bit messy, because we had to manage the relative orders of both phase lists. Indeed, there was already some inconsistency between the precise orders!
This commit refactors the emit functions to share the same phase list, and thus guarantees they will always be in the same order.
PR Close#51498
`syntheticHostListener` and `listener` have ordering dependencies. We reuse the existing ordering phase, and generalize it to also order create mode instructions.
PR Close#51498
Animation listeners on host bindings result in a special `syntheticHostListener` instruction. We can now emit this instruction.
Additionally, the naming phase for events has been slightly refactored to smoothly incorporate whether the event is from a host listener, as well as whether it is an animation listener.
PR Close#51498
For host bindings, `TemplateDefinitionBuilder` seems to use a different binding ordering, in which style bindings come after all the property bindings. We approximate that by treating `hostProperty` differently from `property` in the ordering phase.
PR Close#51498
The template pipeline is already capable of parsing and processing class and style attributes on templates. We now extend that functionality to host bindings.
The parser, for some reason, splits out class and style attributes into a `specialAttributes` field. We merge them back into the main attributes map, and allow the template pipeline to process them normally.
PR Close#51498
TemplateDefinitionBuilder only extracts host attributes if they are text attributes. For example, `[attr.foo]="'my-value'"` is not extracted despite being a string literal, because it is not a text attribute.
PR Close#51498
Host property bindings can be animation bindings, and should be ingested and emitted as such, as well as being processed by the renaming phase.
PR Close#51498
Host bindings can apply static attributes. These will be extracted to a `hostAttrs` field on the host binding function's metadata.
In order to achieve this, we add an `attributes` field to the host binding job. Then, we peform attribute exraction on host bindings. We finally populate the `attributes` field directly, instead of relying on a `consts` array.
PR Close#51498
Convert `CompilationJob` into a abstract class in order to extract common code. Separate host binding jobs and units, in order to allow for more code sharing.
PR Close#51498
Adds a new phase to resolve element placeholders in i18n messages.
This requires adding the i18n message to element ops, which means the
creation of i18n start/end ops can now be done in a separate phase
instead of during ingestion.
PR Close#51353
Creates a new `ExtractedMessageOp` which is consumed by the const
collection pahse to serialize the i18n message into the consts array.
Also adds support to the consts array for initialization statements.
PR Close#51353
Payam Valadkhan