angular-docs-cn/aio/content/guide/deprecations.md

Deprecated APIs and Features

Angular strives to balance innovation and stability. Sometimes, APIs and features become obsolete and need to be removed or replaced so that Angular can stay current with new best practices, changing dependencies, or changes in the (web) platform itself.

To make these transitions as easy as possible, we deprecate APIs and features for a period of time before removing them. This gives you time to update your apps to the latest APIs and best practices.

This guide contains a summary of all Angular APIs and features that are currently deprecated.

Features and APIs that were deprecated in v6 or earlier are candidates for removal in version 9 or any later major version. For information about Angular's deprecation and removal practices, see Angular Release Practices.

For step-by-step instructions on how to update to the latest Angular release, use the interactive update guide at update.angular.io.

Index

To help you future-proof your apps, the following table lists all deprecated APIs and features, organized by the release in which they are candidates for removal. Each item is linked to the section later in this guide that describes the deprecation reason and replacement options.

Area	API or Feature	May be removed in
@angular/common	Pipes using Intl API	v9
@angular/common	ReflectiveInjector	v9
@angular/core	CollectionChangeRecord	v9
@angular/core	DefaultIterableDiffer	v9
@angular/core	ReflectiveKey	v9
@angular/core	RenderComponentType	v9
@angular/core	Renderer	v9
@angular/core	RootRenderer	v9
@angular/core	ViewEncapsulation.Native	v9
@angular/forms	ngForm element selector	v9
@angular/forms	NgFormSelectorWarning	v9
@angular/forms	ngModel with reactive forms	v9
@angular/router	preserveQueryParams	v9
@angular/upgrade	@angular/upgrade	v9
@angular/upgrade	getAngularLib	v9
@angular/upgrade	setAngularLib	v9
template syntax	/deep/, >>>, and ::ng-deep	unspecified
template syntax	<template>	v9
service worker	versionedFiles setting	v9
polyfills	reflect-metadata	v9
@angular/core	defineInjectable	v11
@angular/router	loadChildren string syntax	v11
@angular/router	ActivatedRoute params and queryParams properties	unspecified

Deprecated APIs

This section contains a complete list all of the currently-deprecated APIs, with details to help you plan your migration to a replacement.

Tip: In the API reference section of this doc site, deprecated APIs are indicated by strikethrough. You can filter the API list by Status: deprecated.

{@a common}

@angular/common

API	Replacement	Deprecation announced	Notes
DeprecatedI18NPipesModule	CommonModule	v5	See Pipes
DeprecatedCurrencyPipe	CurrencyPipe	v5	See Pipes
DeprecatedDatePipe	DatePipe	v5	See Pipes
DeprecatedDecimalPipe	DecimalPipe	v5	See Pipes
DeprecatedPercentPipe	PercentPipe	v5	See Pipes

{@a core}

@angular/core

API	Replacement	Deprecation announced	Notes
CollectionChangeRecord	IterableChangeRecord	v4	none
DefaultIterableDiffer	n/a	v4	Not part of public API.
defineInjectable	ɵɵdefineInjectable	v8	Used only in generated code. No source code should depend on this API.
ReflectiveInjector	Injector.create	v5	See ReflectiveInjector
ReflectiveKey	none	v5	none
RenderComponentType	RendererType2 and Renderer2	v4	none
Renderer	Renderer2	v4	none
RootRenderer	RendererFactory2	v4	none
ViewEncapsulation.Native	ViewEncapsulation.ShadowDom	v6	Use the native encapsulation mechanism of the renderer. See view.ts.
WtfScopeFn	none	v8	See Web Tracing Framework
wtfCreateScope	none	v8	See Web Tracing Framework
wtfStartTimeRange	none	v8	See Web Tracing Framework
wtfEndTimeRange	none	v8	See Web Tracing Framework
wtfLeave	none	v8	See Web Tracing Framework

{@a forms}

@angular/forms

API	Replacement	Deprecation announced	Notes
NgFormSelectorWarning	n/a	v6	See ngForm.

{@a router}

@angular/router

API	Replacement	Deprecation announced	Notes
preserveQueryParams	queryParamsHandling	v4	none

{@a platform-webworker}

@angular/platform-webworker

API	Replacement	Deprecation announced	Notes
All entry points	none	v8	See platform-webworker.

{@a platform-webworker-dynamic}

@angular/platform-webworker-dynamic

API	Replacement	Deprecation announced	Notes
All entry points	none	v8	See platform-webworker.

{@a upgrade}

@angular/upgrade

API	Replacement	Deprecation announced	Notes
All entry points	@angular/upgrade/static	v5	See Upgrading from AngularJS.

{@a upgrade-static}

@angular/upgrade/static

API	Replacement	Deprecation announced	Notes
getAngularLib	getAngularJSGlobal	v5	See Upgrading from AngularJS.
setAngularLib	setAngularJSGlobal	v5	See Upgrading from AngularJS.

{@a deprecated-features}

Deprecated features

This section lists all of the currently-deprecated features, which includes template syntax, configuration options, and any other deprecations not listed in the Deprecated APIs section above. It also includes deprecated API usage scenarios or API combinations, to augment the information above.

{@a wtf}

Web Tracing Framework integration

Angular previously has supported an integration with the Web Tracing Framework (WTF) for performance testing of Angular applications. This integration has not been maintained and likely does not work for the majority of Angular applications today. As a result, we are deprecating the integration in Angular version 8.

{@a deep-component-style-selector}

/deep/, >>> and :ng-deep component style selectors

The shadow-dom-piercing descendant combinator is deprecated and support is being removed from major browsers and tools. As such, in v4 we deprecated support in Angular for all 3 of /deep/, >>> and ::ng-deep. Until removal, ::ng-deep is preferred for broader compatibility with the tools.

For more information, see /deep/, >>>, and ::ng-deep in the Component Styles guide.

{@a template-tag}

<template> tag

The <template> tag was deprecated in v4 to avoid colliding with the DOM's element of the same name (such as when using web components). Use <ng-template> instead. For more information, see the Ahead-of-Time Compilation guide.

{@a ngform}

ngForm element selector

Support for using ngForm element selector was deprecated in v6. It has been deprecated to be consistent with other core Angular selectors, which are typically written in kebab-case.

Deprecated:

<ngForm #myForm="ngForm">

Replacement:

<ng-form #myForm="ngForm">

The NgFormSelectorWarning directive is solely used to display warnings when the deprecated ngForm selector is used.

{@a ngmodel-reactive}

ngModel with reactive forms

Support for using the ngModel input property and ngModelChange event with reactive form directives was deprecated in version 6.

For more information, see the usage notes for FormControlDirective and FormControlName.

{@a sw-versionedfiles}

Service worker versionedFiles

In the service worker configuration file ngsw-config.json, versionedFiles and files have the same behavior. As of v6, versionedFiles is deprecated; use files instead.

For more information, see Service Worker Configuration.

{@a reflectiveinjector}

ReflectiveInjector

In v5, Angular replaced the ReflectiveInjector with the StaticInjector. The injector no longer requires the Reflect polyfill, reducing application size for most developers.

Before:

ReflectiveInjector.resolveAndCreate(providers);

After:

Injector.create({providers});

{@a i18n-pipes}

Pipes using Intl API

Angular used to rely on the browser to provide number, date, and currency formatting using browser i18n APIs. This practice meant that most apps needed to use a polyfill, users were seeing inconsistent results across browsers, and common formats (such as the currency pipe) didn’t match developer expectations out of the box.

In version 4.3, Angular introduced new number, date, and currency pipes that increase standardization across browsers and eliminate the need for i18n polyfills. These pipes use the Unicode Common Locale Data Repository (CLDR) instead of the JS Intl API to provide extensive locale support.

In version 5.0.0, Angular updated its standard pipes to use the CLRD implementation. At that time, Angular also added DeprecatedI18NPipesModule and related APIs to provide limited-time access to the old behavior. If you need to use these Deprecated* pipes, see Angular change log and the Date Formats mappings.

Reminder: If you use these Deprecated* pipes, you should migrate to the current APIs listed above as soon as possible. These deprecated APIs are candidates for removal in version 9.

{@a loadChildren}

loadChildren string syntax

When Angular first introduced lazy routes, there wasn't browser support for dynamically loading additional JavaScript. Angular created our own scheme using the syntax loadChildren: './lazy/lazy.module#LazyModule' and built tooling to support it. Now that ECMAScript dynamic import is supported in many browsers, Angular is moving toward this new syntax.

In version 8, the string syntax for the loadChildren route specification was deprecated, in favor of new syntax that uses import() syntax.

Before:

const routes: Routes = [{
  path: 'lazy',
  // The following string syntax for loadChildren is deprecated
  loadChildren: './lazy/lazy.module#LazyModule'
}];

After:

const routes: Routes = [{
  path: 'lazy',
  // The new import() syntax
  loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule)
}];

Version 8 update: When you update to version 8, the ng update command performs the transformation automatically. Prior to version 7, the import() syntax only works in JIT mode (with view engine).

Declaration syntax: It's important to follow the route declaration syntax loadChildren: () => import('...').then(m => m.ModuleName) to allow ngc to discover the lazy-loaded module and the associated NgModule. You can find the complete list of allowed syntax constructs here. These restrictions will be relaxed with the release of Ivy since it'll no longer use NgFactories.

{@a activatedroute-props}

ActivatedRoute params and queryParams properties

ActivatedRoute contains two properties that are less capable than their replacements and may be deprecated in a future Angular version.

Property	Replacement
params	paramMap
queryParams	queryParamMap

For more information see the Router guide.

{@a reflect-metadata}

Dependency on a reflect-metadata polyfill in JIT mode

Angular applications, and specifically applications that relied on the JIT compiler, used to require a polyfill for the reflect-metadata APIs.

The need for this polyfill was removed in Angular version 8.0 (see #14473), rendering the presence of the poylfill in most Angular applications unnecessary. Because the polyfill can be depended on by 3rd-party libraries, instead of removing it from all Angular projects, we are deprecating the requirement for this polyfill as of version 8.0. This should give library authors and application developers sufficient time to evaluate if they need the polyfill, and perform any refactoring necessary to remove the dependency on it.

In a typical Angular project, the polyfill is not used in production builds, so removing it should not impact production applications. The goal behind this removal is overall simplification of the build setup and decrease in the number of external dependencies.

{@a static-query-resolution}

@ViewChild() / @ContentChild() static resolution as the default

See the dedicated migration guide for static queries.

{@a contentchild-input-together}

@ContentChild() / @Input() used together

The following pattern is deprecated:

@Input() @ContentChild(TemplateRef) tpl !: TemplateRef<any>;

Rather than using this pattern, separate the two decorators into their own properties and add fallback logic as in the following example:

@Input() tpl !: TemplateRef<any>;
@ContentChild(TemplateRef) inlineTemplate !: TemplateRef<any>;

{@a cant-assign-template-vars}

Cannot assign to template variables

In the following example, the two-way binding means that optionName should be written when the valueChange event fires.

<option *ngFor="let optionName of options" [(value)]="optionName"></option>

However, in practice, Angular simply ignores two-way bindings to template variables. Starting in version 8, attempting to write to template variables is deprecated. In a future version, we will throw to indicate that the write is not supported.

<option *ngFor="let optionName of options" [value]="optionName"></option>

{@a binding-to-innertext}

Binding to innerText in platform-server

Domino, which is used in server-side rendering, doesn't support innerText, so in platform-server's "domino adapter", there was special code to fall back to textContent if you tried to bind to innerText.

These two properties have subtle differences, so switching to textContent under the hood can be surprising to users. For this reason, we are deprecating this behavior. Going forward, users should explicitly bind to textContent when using Domino.

{@a wtf-apis}

wtfStartTimeRange and all wtf* APIs

All of the wtf* APIs are deprecated and will be removed in a future version.

{@a webworker-apps}

Running Angular applications in platform-webworker

The @angular/platform-* packages enable Angular to be run in different contexts. For examples, @angular/platform-server enables Angular to be run on the server, and @angular/platform-browser enables Angular to be run in a web browser.

@angular/platform-webworker was introduced in Angular version 2 as an experiment in leveraging Angular's rendering architecture to run an entire web application in a web worker. We've learned a lot from this experiment and have come to the conclusion that running the entire application in a web worker is not the best strategy for most applications.

Going forward, we will focus our efforts related to web workers around their primary use case of offloading CPU-intensive, non-critical work needed for initial rendering (such as in-memory search and image processing). Learn more in the guide to Using Web Workers with the Angular CLI.

As of Angular version 8, all platform-webworker APIs are deprecated. This includes both packages: @angular/platform-webworker and @angular/platform-webworker-dynamic.

Angular version 9 schematics

{@a renderer-to-renderer2}

Migrating from Renderer to Renderer2

See the dedicated migration guide for Renderer.

{@a undecorated-classes}

Migrating undecorated classes

See the dedicated migration guide for undecorated classes.

{@a removed}

Removed APIs

The following APIs have been removed starting with version 8.0.0:

Package	API	Replacement	Notes
@angular/http	All exports	@angular/common/http	See below.
@angular/http/testing	All exports	@angular/common/http/testing	See below.
@angular/platform-browser	DOCUMENT	DOCUMENT in @angular/common	Updating to version 8 with ng update changes this automatically.
@angular/core/testing	TestBed.deprecatedOverrideProvider()	TestBed.overrideProvider()	none
@angular/core/testing	TestBedStatic.deprecatedOverrideProvider()	TestBedStatic.overrideProvider()	none

{@a http}

@angular/http

The entire @angular/http package has been removed. Use @angular/common/http instead.

The new API is a smaller, easier, and more powerful way to make HTTP requests in Angular. The new API simplifies the default ergonomics: There is no need to map by invoking the .json() method. It also supports typed return values and interceptors.

To update your apps:

• Replace HttpModule with HttpClientModule (from @angular/common/http) in each of your modules.
• Replace the Http service with the HttpClient service.
• Remove any map(res => res.json()) calls. They are no longer needed.

For more information about using @angular/common/http, see the HttpClient guide.

@angular/http	Closest replacement in @angular/common/http
BaseRequestOptions	HttpRequest
BaseResponseOptions	HttpResponse
BrowserXhr
Connection	HttpBackend
ConnectionBackend	HttpBackend
CookieXSRFStrategy	HttpClientXsrfModule
Headers	HttpHeaders
Http	HttpClient
HttpModule	HttpClientModule
Jsonp	HttpClient
JSONPBackend	JsonpClientBackend
JSONPConnection	JsonpClientBackend
JsonpModule	HttpClientJsonpModule
QueryEncoder	HttpUrlEncodingCodec
ReadyState	HttpBackend
Request	HttpRequest
RequestMethod	HttpClient
RequestOptions	HttpRequest
RequestOptionsArgs	HttpRequest
Response	HttpResponse
ResponseContentType	HttpClient
ResponseOptions	HttpResponse
ResponseOptionsArgs	HttpResponse
ResponseType	HttpClient
URLSearchParams	HttpParams
XHRBackend	HttpXhrBackend
XHRConnection	HttpXhrBackend
XSRFStrategy	HttpClientXsrfModule

@angular/http/testing	Closest replacement in @angular/common/http/testing
MockBackend	HttpTestingController
MockConnection	HttpTestingController