After the introduction of the view engine, we can drop a lot of code that is not used any more.
This should reduce the size of the app bundles because a lot of this code was not being properly tree-shaken by today's tools even though it was dead code.
- Don’t use the animation renderer if a component
used style encapsulation but no animations.
- The `AnimationRenderer` should be cached in the same
lifecycle as its delegate.
- Trigger names need to be namespaced per component type.
The rationale of this change is to improve the inter-operability with web
components that might make use of the `<template>` tag.
DEPRECATION
The template tags and template attribute are deprecated:
<template ngFor [ngFor]=items let-item><li>...</li></template>
<li template="ngFor: let item of items">...</li>
should be rewritten as:
<ng-template ngFor [ngFor]=items let-item><li>...</li></ng-template>
Note that they still be supported in 4.x with a deprecartion warning in
development mode.
MIGRATION
- `template` tags (or elements with a `template` attribute) should be rewritten
as a `ng-template` tag,
- `ng-content` selectors should be updated to referto a `ng-template` where they
use to refer to a template: `<ng-content selector="template[attr]">` should be
rewritten as `<ng-content selector="ng-template[attr]">`
- if you consume a component relying on your templates being actual `template`
elements (that is they include a `<ng-content selector="template[attr]">`). You
should still migrate to `ng-template` and make use of `ngProjectAs` to override
the way `ng-content` sees the template:
`<ng-template projectAs="template[attr]">`
- while `template` elements are deprecated in 4.x they continue to work.
Use `RendererV2` instead of `Renderer` now. `Renderer` can still be injected
and delegates to `RendererV2`.
Use `RendererFactoryV2` instead of `RootRenderer`. `RootRenderer` cannot be used
anymore.
BREAKING CHANGE:
- `RootRenderer` cannot be used any more, use `RendererFactoryV2` instead.
Note: `Renderer` can still be injected/used, but is deprecated.
Some versions of TypeScript are super slow to compile functions that
contain a lot of `if` conditions in them. Splitting the handle event
expressions per element is similar to what we did in the old codegen.
Note that this does not yet include enabling the view engine
by default.
Included refactoring:
- view engine: split namespace of elements / attributes already
when creating the `NodeDef`
- view engine: when injecting the old `Renderer`, use an implementation
that is based on `RendererV2`
- view engine: store view queries in the component view, not
on the host element
Included refactoring:
- splits the `RendererV2` into a `RendererFactoryV2` and a `RendererV2`
- makes the `DebugRendererV2` a private class in `@angular/core`
- remove `setBindingDebugInfo` from `RendererV2`, but rename `RendererV2.setText` to
`RendererV2.setValue` and allow it on comments and text nodes.
Part of #14013
Aspects: di, query, content projection
Included refactoring:
- use a number as query id
- use a bloom filter for aggregating matched queries of nested elements
- separate static vs dynamic queries
Part of #14013