Commit graph

360 commits

Author SHA1 Message Date
Pete Bacon Darwin
4dc27a7eaa refactor(core): rename ɵɵFactoryDef to ɵɵFactoryDeclaration (#41119)
Th `ɵɵFactoryDef` type will appear in published libraries, via their typings
files, to describe what type dependencies a DI factory has. The parameters
on this type are used by tooling such as the Language Service to understand
the DI dependencies of the class being created by the factory.

This commit moves the type to the `public_definitions.ts` file alongside
the other types that have a similar role, and it renames it to `ɵɵFactoryDeclaration`
to align it with the other declaration types such as `ɵɵDirectiveDeclaration`
and so on.

PR Close #41119
2021-03-22 08:57:18 -07:00
Pete Bacon Darwin
88683702e5 refactor(core): rename ...WithMeta types to ...Declaration and alias to unknown (#41119)
These types are only used in the generated typings files to provide
information to the Angular compiler in order that it can compile code
in downstream libraries and applications.

This commit aliases these types to `unknown` to avoid exposing the
previous alias types such as `ɵɵDirectiveDef`, which are internal to
the compiler.

PR Close #41119
2021-03-22 08:57:18 -07:00
Andrew Kushnir
32dd3c5dd1 refactor(core): co-locate read/write patched data functions (#41097)
This commit refactors Ivy runtime code to move `readPatchedData` and `attachPatchedData` functions to a single
location for better maintainability and to make it easier to do further changes if needed.  The `readPatchedLView`
function was also moved to the same location (since it's a layer on top of the `readPatchedData` function).

PR Close #41097
2021-03-08 08:38:00 -08:00
Pete Bacon Darwin
0f818f36d7 refactor(core): use unknown rather than never for private properties (#41040)
Before `unknown` was available, the `never` type was used to discourage
application developers from using "private" properties. The `unknown` type
is much better suited for this.

PR Close #41040
2021-03-04 11:04:26 -08:00
Misko Hevery
1e4b51e9f7 fix(core): improve injector debug information in ngDevMode (#40476)
- `LViewDebug` now properly shows when `TNode` has `NO_NODE_INJECTOR`.
- Provide `injectorResolutionPath` property `DebugNode`

PR Close #40476
2021-01-22 10:21:25 -08:00
Misko Hevery
e32b6256ce fix(core): QueryList should not fire changes if the underlying list did not change. (#40091)
Previous implementation would fire changes `QueryList.changes.subscribe`
whenever the `QueryList` was recomputed. This resulted in artificially
high number of change notifications, as it is possible that recomputing
`QueryList` results in the same list. When the `QueryList` gets recomputed
is an implementation detail and it should not be the thing which determines
how often change event should fire.

This change introduces a new `emitDistinctChangesOnly` option for
`ContentChildren` and `ViewChildren`.

```
export class QueryCompWithStrictChangeEmitParent {
  @ContentChildren('foo', {
    // This option will become the default in the future
    emitDistinctChangesOnly: true,
  })
  foos!: QueryList<any>;
}
```

PR Close #40091
2021-01-14 13:55:02 -08:00
arturovt
df27027ecb fix(core): remove application from the testability registry when the root view is removed (#39876)
In the new behavior Angular removes applications from the testability registry when the
root view gets destroyed. This eliminates a memory leak, because before that the
TestabilityRegistry holds references to HTML elements, thus they cannot be GCed.

PR Close #22106

PR Close #39876
2020-12-02 12:56:04 -08:00
Mitchell Wills
a1b6ad07a8 fix(core): Allow passing AbstractType to the inject function (#37958)
This is a type only change that replaces `Type<T>|InjectionToken<T>` with
`Type<T>|AbstractType<T>|InjectionToken<T>` in the injector.

PR Close #37958
2020-11-24 10:42:21 -08:00
Misko Hevery
3b2e5be6cb refactor(core): clean up circular dependencies (#39722)
Clean up circular dependencies in core by pulling symbols out to their
respective files.

PR Close #39722
2020-11-18 09:15:29 -08:00
Misko Hevery
c461acd12e refactor(core): Remove circular dependency on ApplicationRef (#39621)
`ViewRef` and `ApplicationRef` had a circular reference. This change
introduces `ViewRefTracker` which is a subset of `ApplicationRef` for
this purpose.

PR Close #39621
2020-11-16 09:12:46 -08:00
Misko Hevery
e6ae0c5349 refactor(core): Remove circular dependency between LContainer and ViewRef. (#39621)
`LContainer` stores `ViewRef`s this is not quite right as it creates
circular dependency between the two types. Also `LContainer` should not
be aware of `ViewRef` which iv ViewEngine specific construct.

PR Close #39621
2020-11-16 09:12:46 -08:00
Andrew Kushnir
c83b2ad87f docs: tView.preOrderHooks and tView.preOrderCheckHooks docs update (#39497)
This commit updates the docs for the `tView.preOrderHooks` and `tView.preOrderCheckHooks` TView
fields. Current docs are not up-to-date as it was pointed out in #39439.

Closes #39439.

PR Close #39497
2020-10-29 16:25:39 -07:00
Misko Hevery
68d4de6770 refactor(core): Replace ExpandoInstructions with HostBindingOpCodes (#39301)
The `ExpandoInstructions` was unnecessarily convoluted way to solve the
problem of calling the `HostBindingFunction`s on components and
directives. The code was complicated and hard to fallow.

The replacement is a simplified way to achieve the same thing, which
is also more efficient in space and speed.

PR Close #39301
2020-10-22 09:35:48 -07:00
Misko Hevery
08f3d62391 refactor(core): clean up circular dependencies (#39233)
Moved code from `interfaces/i18n.ts` which was causing circular dependencies

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
54303688fa refactor(core): Consistent use of HEADER_OFFSET (in ɵɵ* instructions only) (#39233)
IMPORTANT: `HEADER_OFFSET` should only be refereed to the in the `ɵɵ*` instructions to translate
instruction index into `LView` index. All other indexes should be in the `LView` index space and
there should be no need to refer to `HEADER_OFFSET` anywhere else.

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
bc5005e35b refactor(core): cleanup i18n/icu data structures (#39233)
- Made `*OpCodes` array branded for safer type checking.
- Simplify `I18NRemoveOpCodes` encoding.
- Broke out  `IcuCreateOpCodes` from `I18nMutableOpCodes`.

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
e1f80d73a8 refactor(core): rename COMMENT_MARKER to ICU_MARKER (#39233)
`COMMENT_MARKER` is a generic name which does not make it obvious that
it is used for ICU use case. `ICU_MARKER` is more explicit as it is used
exclusively with ICUs.

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
70f1e2e04a refactor(core): Create TNodeType.Text to display full template in TView debug (#39233)
When looking at `TView` debug template only Element nodes were displayed
as `TNode.Element` was used for both `RElement` and `RText`.
Additionally no text was stored in `TNode.value`. The result was that
the whole template could not be reconstructed. This refactoring creates
`TNodeType.Text` and store the text value in `TNode.value`.

The refactoring also changes `TNodeType` into flag-like structure make
it more efficient to check many different types at once.

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
d50df92568 refactor(core): Remove hack where we TIcu was stored in tagName (#39233)
Remove casting where we stored `TIcu` in `TNode.tagName` which was of
type `string` rather than `TIcu'. (renamed to `TNode.value` in previous
commit.)

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
2e237abb09 refactor(core): Change TName.tagName to a more generic value name. (#39233)
This is a pre-requisite for making the `TNode.value` a generic storage
mechanism for attaching data to `TNode`.

PR Close #39233
2020-10-21 18:33:00 -07:00
Misko Hevery
ca11ef2376 fix(core): Store ICU state in LView rather than in TView (#39233)
Before this refactoring/fix the ICU would store the current selected
index in `TView`. This is incorrect, since if ICU is in `ngFor` it will
cause issues in some circumstances. This refactoring properly moves the
state to `LView`.

closes #37021
closes #38144
closes #38073

PR Close #39233
2020-10-21 18:33:00 -07:00
Bjarki
e8d47c2d41 feat(core): allow returning Trusted Types from SanitizerFn (#39218)
Sanitizers in Angular currently return strings, which will then
eventually make their way down to the DOM, e.g. as the value of an
attribute or property. This may cause a Trusted Types violation. As a
step towards fixing that, make it possible to return Trusted Types from
the SanitizerFn interface, which represents the internal sanitization
pipeline. DOM renderer interfaces are also updated to reflect the fact
that setAttribute and setAttributeNS must be able to accept Trusted
Types.

PR Close #39218
2020-10-16 08:13:52 -07:00
Misko Hevery
494a2f3be4 refactor(core): Create NodeInjectorOffset type which better describes NodeInjector (#38707)
`NodeInjector` is store in expando as a list of values in an array. The
offset constant into the array have been brought together into a single
`NodeInjectorOffset` enum with better documentation explaining their usage.

PR Close #38707
2020-09-28 16:15:59 -04:00
Misko Hevery
5a86fb33ba refactor(core): Rename TView.node to TView.declTNode. (#38707)
The value stored in `TView.node` is really the declaration `TNode`,
therefore renaming to make it more explicit.

PR Close #38707
2020-09-28 16:15:59 -04:00
Misko Hevery
5db84d7221 refactor(core): Remove TViewNode as it is no longer used. (#38707)
Previous commit change the logic to not rely on the `TViewNode` this
change removes it entirely.

PR Close #38707
2020-09-28 16:15:59 -04:00
Misko Hevery
eb32b6bd6b refactor(core): Remove reliance on TNodeType.View. (#38707)
`TNodeType.View` was created to support inline views. That feature did
not materialize and we have since removed the instructions for it, leave
 an unneeded `TNodeType.View` which was still used in a very
 inconsistent way. This change no longer created `TNodeType.View` (and
 there will be a follow up chang to completely remove it.)

Also simplified the mental model so that `LView[HOST]`/`LView[T_HOST]`
always point to the insertion location of the `LView`.

PR Close #38707
2020-09-28 16:15:59 -04:00
Misko Hevery
b2579d43cd refactor(core): Add injector debug information to LViewDebug (#38707)
Extended the `LViewDebug` to display node-injector information for each
node.

PR Close #38707
2020-09-28 16:15:59 -04:00
Andrew Kushnir
95b8a8706a refactor(core): reduce the number of circular deps (#38805)
This commit updates several import statements in the core package to decrease the number of
cycles detected by the dependency checker tool.

PR Close #38805
2020-09-18 11:20:08 -07:00
Andrew Kushnir
cb05c0102f fix(core): move generated i18n statements to the consts field of ComponentDef (#38404)
This commit updates the code to move generated i18n statements into the `consts` field of
ComponentDef to avoid invoking `$localize` function before component initialization (to better
support runtime translations) and also avoid problems with lazy-loading when i18n defs may not
be present in a chunk where it's referenced.

Prior to this change the i18n statements were generated at the top leve:

```
var I18N_0;
if (typeof ngI18nClosureMode !== "undefined" && ngI18nClosureMode) {
    var MSG_X = goog.getMsg(“…”);
    I18N_0 = MSG_X;
} else {
    I18N_0 = $localize('...');
}

defineComponent({
    // ...
    template: function App_Template(rf, ctx) {
        i0.ɵɵi18n(2, I18N_0);
    }
});
```

This commit updates the logic to generate the following code instead:

```
defineComponent({
    // ...
    consts: function() {
        var I18N_0;
        if (typeof ngI18nClosureMode !== "undefined" && ngI18nClosureMode) {
            var MSG_X = goog.getMsg(“…”);
            I18N_0 = MSG_X;
        } else {
            I18N_0 = $localize('...');
        }
        return [
            I18N_0
        ];
    },
    template: function App_Template(rf, ctx) {
        i0.ɵɵi18n(2, 0);
    }
});
```

Also note that i18n template instructions now refer to the `consts` array using an index
(similar to other template instructions).

PR Close #38404
2020-08-17 10:13:57 -07:00
Misko Hevery
250e299dc3 refactor(core): break i18n.ts into smaller files (#38368)
This commit contains no changes to code. It only breaks `i18n.ts` file
into `i18n.ts` + `i18n_apply.ts` + `i18n_parse.ts` +
`i18n_postprocess.ts` for easier maintenance.

PR Close #38368
2020-08-10 15:07:42 -07:00
Misko Hevery
6d8c73a4d6 fix(core): Store the currently selected ICU in LView (#38345)
The currently selected ICU was incorrectly being stored it `TNode`
rather than in `LView`.

Remove: `TIcuContainerNode.activeCaseIndex`
Add: `LView[TIcu.currentCaseIndex]`

PR Close #38345
2020-08-10 12:41:17 -07:00
Misko Hevery
702958e968 refactor(core): add debug ranges to LViewDebug with matchers (#38359)
This change provides better typing for the `LView.debug` property which
is intended to be used by humans while debugging the application with
`ngDevMode` turned on.

In addition this chang also adds jasmine matchers for better asserting
that `LView` is in the correct state.

PR Close #38359
2020-08-06 16:58:11 -07:00
Misko Hevery
3821dc5f6c refactor(core): add human readable debug for i18n (#38154)
I18n code breaks up internationalization into opCodes which are then stored
in arrays. To make it easier to debug the codebase this PR adds `debug`
property to the arrays which presents the data in human readable format.

PR Close #38154
2020-08-06 15:20:17 -07:00
crisbeto
38a7021d5e fix(core): error due to integer overflow when there are too many host bindings (#38014)
We currently use 16 bits to store information about nodes in a view.
The 16 bits give us 65536 entries in the array, but the problem is that while
the number is large, it can be reached by ~4300 directive instances with host
bindings which could realistically happen is a very large view, as seen in #37876.
Once we hit the limit, we end up overflowing which eventually leads to a runtime error.

These changes bump to using 20 bits which gives us around 1048576 entries in
the array or 16 times more than the current amount which could still technically
be reached, but is much less likely and the user may start hitting browser limitations
by that point.

I picked the 20 bit number since it gives us enough buffer over the 16 bit one,
while not being as massive as a 24 bit or 32 bit.

I've also added a dev mode assertion so it's easier to track down if it happens
again in the future.

Fixes #37876.

PR Close #38014
2020-07-17 12:58:15 -07:00
Misko Hevery
737506e79c fix(core): Allow modification of lifecycle hooks any time before bootstrap (#35464)
Currently we read lifecycle hooks eagerly during `ɵɵdefineComponent`.
The result is that it is not possible to do any sort of meta-programing
such as mixins or adding lifecycle hooks using custom decorators since
any such code executes after `ɵɵdefineComponent` has extracted the
lifecycle hooks from the prototype. Additionally the behavior is
inconsistent between AOT and JIT mode. In JIT mode overriding lifecycle
hooks is possible because the whole `ɵɵdefineComponent` is placed in
getter which is executed lazily. This is because JIT mode must compile a
template which can be specified as `templateURL` and those we are
waiting for its resolution.

- `+` `ɵɵdefineComponent` becomes smaller as it no longer needs to copy
  lifecycle hooks from prototype to `ComponentDef`
- `-` `ɵɵNgOnChangesFeature` feature is now always included with the
  codebase as it is no longer tree shakable.

Previously we have read lifecycle hooks from prototype in the
`ɵɵdefineComponent` so that lifecycle hook access would be monomorphic.
This decision was made before we had `T*` data structures. By not
reading the lifecycle hooks we are moving the megamorhic read form
`ɵɵdefineComponent` to instructions. However, the reads happen on
`firstTemplatePass` only and are subsequently cached in the `T*` data
structures. The result is that the overall performance should be same
(or slightly better as the intermediate `ComponentDef` has been
removed.)

- [ ] Remove `ɵɵNgOnChangesFeature` from compiler. (It will no longer
      be a feature.)
- [ ] Discuss the future of `Features` as they hinder meta-programing.

Fix #30497

PR Close #35464
2020-07-15 16:22:46 -07:00
Paul Gschwendtner
97dc85ba5e feat(core): support injection token as predicate in queries (#37506)
Currently Angular internally already handles `InjectionToken` as
predicates for queries. This commit exposes this as public API as
developers already relied on this functionality but currently use
workarounds to satisfy the type constraints (e.g. `as any`).

We intend to make this public as it's low-effort to support, and
it's a significant key part for the use of light-weight tokens as
described in the upcoming guide: https://github.com/angular/angular/pull/36144.

In concrete, applications might use injection tokens over classes
for both optional DI and queries, because otherwise such references
cause classes to be always retained. This was also an issue in View
Engine, but now with Ivy, this pattern became worse, as factories are
directly attached to retained classes (ultimately ending up in the
production bundle, while being unused).

More details in the light-weight token guide and in: https://github.com/angular/angular-cli/issues/16866.

Closes #21152. Related to #36144.

PR Close #37506
2020-06-11 13:21:11 -07:00
Joey Perrott
d1ea1f4c7f build: update license headers to reference Google LLC (#37205)
Update the license headers throughout the repository to reference Google LLC
rather than Google Inc, for the required license headers.

PR Close #37205
2020-05-26 14:26:58 -04:00
Miško Hevery
cda2530df5 fix(core): Host classes should not be fed back into @Input (#35889)
Previously all static styling information (including the ones from component/directive host bindings) would get merged into a single value before it would be written into the `@Input('class'/'style')`. The new behavior specifically excludes host values from the `@Input` bindings.

Fix #35383

PR Close #35889
2020-05-14 15:54:13 -07:00
Andrew Scott
aaa89bb715 refactor(core): rename refreshDynamicEmbeddedViews to refreshEmbeddedViews (#37117)
Dynamic embedded views were conceptually different from inline embedded views, but we have since
removed the inline embedded views so we now only have "embedded views".
See related refactoring work to remove inline embedded views in #34715
and #37073.

PR Close #37117
2020-05-14 15:50:52 -07:00
Andrew Scott
047642556c refactor(core): remove ActiveIndexFlag from LContainer (#37073)
The ActiveIndexFlag is no longer needed because we no longer have "inline embedded views".
There is only one type of embedded view so we do not need complex tracking for
inline embedded views.

HAS_TRANSPLANTED_VIEWS now takes the place of the ACTIVE_INDEX slot as a
simple boolean rather than being a shifted flag inside the ACTIVE_INDEX bits.

PR Close #37073
2020-05-13 16:00:41 -07:00
Andrew Kushnir
0c8adbc4ec refactor(core): remove unused embedded view instructions (#34715)
This commit performs a cleanup and removes unused embedded view instructions and corresponding tests.

PR Close #34715
2020-05-11 10:52:28 -07:00
Andrew Scott
1786586747 fix(core): Refresh transplanted views at insertion point only (#35968)
Only refresh transplanted views at the insertion location in Ivy.
Previously, Ivy would check transplanted views at both the insertion and
declaration points. This is achieved by adding a marker to the insertion
tree when we encounter a transplanted view that needs to be refreshed at
its declaration. We use this marker as an extra indication that we still
need to descend and refresh those transplanted views at their insertion
locations even if the insertion view and/or its parents are not dirty.

This change fixes several issues:

  * Transplanted views refreshed twice if both insertion and declaration
  are dirty. This could be an error if the insertion component changes
  result in data not being available to the transplanted view because it
  is slated to be removed.
  * CheckAlways transplanted views not refreshed if shielded by
  non-dirty OnPush (fixes #35400)
  * Transplanted views still refreshed when insertion tree is detached
  (fixes #21324)

PR Close #35968
2020-04-29 14:31:12 -07:00
crisbeto
3d82aa781d fix(core): attempt to recover from user errors during creation (#36381)
If there's an error during the first creation pass of a `TView`, the data structure may be corrupted which will cause framework assertion failures downstream which can mask the user's error. These changes add a new flag to the `TView` that indicates whether the first creation pass was successful, and if it wasn't we try re-create the `TView`.

Fixes #31221.

PR Close #36381
2020-04-29 08:36:42 -07:00
Joey Perrott
698b0288be build: reformat repo to new clang@1.4.0 (#36613)
PR Close #36613
2020-04-14 12:08:36 -07:00
crisbeto
95fc3d4c5c fix(core): ngOnDestroy on multi providers called with incorrect context (#35840)
Currently destroy hooks are stored in memory as `[1, hook, 5, hook]` where
the numbers represent the index at which to find the context and `hook` is
the function to be invoked. This breaks down for `multi` providers,
because the value at the index will be an array of providers, resulting in
the hook being invoked with an array of all the multi provider values,
rather than the provider that was destroyed. In ViewEngine `ngOnDestroy`
wasn't being called for `multi` providers at all.

These changes fix the issue by changing the structure of the destroy hooks to `[1, hook, 5, [0, hook, 3, hook]]` where the indexes inside the inner array point to the provider inside of the multi provider array. Note that this is slightly different from the original design which called for the structure to be `[1, hook, 5, [hook, hook]`, because in the process of implementing it, I realized that we wouldn't get passing the correct context if only some of the `multi` providers have `ngOnDestroy` and others don't.

I've run the newly-added `view_destroy_hooks` benchmark against these changes and compared it to master. The difference seems to be insignificant (between 1% and 2% slower).

Fixes #35231.

PR Close #35840
2020-04-07 10:31:41 -07:00
Andrew Kushnir
80c68583d1 refactor(core): use more narrow QueryList import to avoid circular deps issue (#36286)
Prior to this commit, the `packages/core/src/render3/interfaces/query.ts` file used to import `QueryList` using `../../linker`, which contains a lot of re-exports and as a result, this one import caused a lot of circular deps cycles reported by the tool that checks such deps. In other places in the code the `QueryList` is imported using more narrow import (`linker/query_list`), so this commit uses the same pattern. This change allowed to reduce the number of known cycles from 343 to 207, the golden file was updated accordingly.

PR Close #36286
2020-03-30 15:31:39 -07:00
JoostK
32ce8b1326 feat(compiler): add dependency info and ng-content selectors to metadata (#35695)
This commit augments the `FactoryDef` declaration of Angular decorated
classes to contain information about the parameter decorators used in
the constructor. If no constructor is present, or none of the parameters
have any Angular decorators, then this will be represented using the
`null` type. Otherwise, a tuple type is used where the entry at index `i`
corresponds with parameter `i`. Each tuple entry can be one of two types:

1. If the associated parameter does not have any Angular decorators,
   the tuple entry will be the `null` type.
2. Otherwise, a type literal is used that may declare at least one of
   the following properties:
   - "attribute": if `@Attribute` is present. The injected attribute's
   name is used as string literal type, or the `unknown` type if the
   attribute name is not a string literal.
   - "self": if `@Self` is present, always of type `true`.
   - "skipSelf": if `@SkipSelf` is present, always of type `true`.
   - "host": if `@Host` is present, always of type `true`.
   - "optional": if `@Optional` is present, always of type `true`.

   A property is only present if the corresponding decorator is used.

   Note that the `@Inject` decorator is currently not included, as it's
   non-trivial to properly convert the token's value expression to a
   type that is valid in a declaration file.

Additionally, the `ComponentDefWithMeta` declaration that is created for
Angular components has been extended to include all selectors on
`ng-content` elements within the component's template.

This additional metadata is useful for tooling such as the Angular
Language Service, as it provides the ability to offer suggestions for
directives/components defined in libraries. At the moment, such
tooling extracts the necessary information from the _metadata.json_
manifest file as generated by ngc, however this metadata representation
is being replaced by the information emitted into the declaration files.

Resolves FW-1870

PR Close #35695
2020-03-24 14:21:42 -07:00
Misko Hevery
01308e4c7c refactor(ivy): Remove TNode.directives in favor of TData (#35050)
`TNode.directives` was introduced in https://github.com/angular/angular/pull/34938. Turns out that it is unnecessary because the information is already present it `TData` when combining with `TNode.directiveStart` and `TNode.directiveEnd`

Mainly this is true (conceptually):
```
expect(tNode.directives).toEqual(
    tData.slice(
        tNode.directivesStart,
        tNode.directivesEnd - tNode.DirectivesStart -1
    )
);
```

The refactoring removes `TNode.directives` and adds `TNode.directiveStyling` as we still need to keep location in the directive in `TNode`

PR Close #35050
2020-02-03 08:56:51 -08:00
Miško Hevery
c1cf46c5c3 refactor(ivy): clean of #34804 from previous merge (#35022)
This is a follow up for https://github.com/angular/angular/pull/34804

PR Close #35022
2020-01-29 16:35:08 -08:00
Misko Hevery
ee8b8f52aa feat(ivy): Change static priority resolution to be same level as directive it belongs to (#34938)
This change changes the priority order of static styling.

Current priority:
```
(least priority)
- Static
  - Component
  - Directives
  - Template
- Dynamic Binding
  - Component
    - Map/Interpolation
    - Property
  - Directives
    - Map/Interpolation
    - Property
  - Template
    - Map/Interpolation
    - Property
(highest priority)
```

The issue with the above priority is this use case:

```
<div style="color: red;" directive-which-sets-color-blue>
```
In the above case the directive will win and the resulting color will be `blue`. However a small change of adding interpolation to the example like so. (Style interpolation is coming in https://github.com/angular/angular/pull/34202)
```
<div style="color: red; width: {{exp}}px" directive-which-sets-color-blue>
```
Changes the priority from static binding to interpolated binding which means now the resulting color is `red`. It is very surprising that adding an unrelated interpolation and style can change the `color` which was not changed. To fix that we need to make sure that the static values are associated with priority of the source (directive or template) where they were declared. The new resulting priority is:

```
(least priority)
- Component
  - Static
  - Map/Interpolation
  - Property
- Directives
  - Static
  - Map/Interpolation
  - Property
- Template
  - Static
  - Map/Interpolation
  - Property
(highest priority)
```

PR Close #34938
2020-01-29 15:41:47 -08:00