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

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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) didnt 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.

We expect to remove the polyfill from most if not all CLI projects via an ng upgrade migration from version 8 to 9.

{@a static-query-resolution}

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

See our 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"></cmp>

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"></cmp>

{@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 platform-webworker}

platform-webworker

The @angular/platform-* packages enable Angular to be run in different contexts. Some examples are running Angular on the server (@angular/platform-server), in the browser (@angular/platform-browser), or in a web worker (@angular/platform-webworker).

Though web worker is useful to offload things requiring lots of processing, pushing whole apps to run in the web worker isn't a winning strategy due to many unresolved issues.

Angular CLI doesn't allow use of these APIs because the build system and bundling doesn't support them. This whole package is deprecated in Angular version 8 and will be removed in the future. If you're currently using the @angular/platform-webworker APIs in production, please reach out to devrel@angular.io and let us know - we're interested in hearing your use cases.

Instead, use web workers primarily for offloading CPU intensive, but functionally not critical, work needed for initial rendering (for example, in memory search, image processing, and so on).

{@a webworker-apps}

platform-webworker Angular applications

platform-webworker has been around since the initial release of Angular version 2. It began as an experiment to leverage Angular's rendering architecture and try something different: 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 pushing entire applications to run in a web worker is not a recipe for success for most applications. This is due to a number of unresolved issues, including:

  • Poor or non-existent support for web worker APIs in web crawlers/indexers.
  • Poor support in build and bundling tooling.

As a result, as of Angular version 8, we are deprecating the platform-webworker APIs in Angular. This consists of both NPM packages, @angular/platform-webworker and @angular/platform-webworker-dynamic.

Going forward, we will focus our efforts related to web workers around their primary use case of offloading CPU-intensive but not critical work.

{@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()] (api/core/testing/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:

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