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/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {Type} from '../type';
import {stringify} from '../util';
import {getClosureSafeProperty} from '../util/property';
import {InjectableDef, defineInjectable, getInjectableDef} from './defs';
import {resolveForwardRef} from './forward_ref';
import {InjectionToken} from './injection_token';
import {Inject, Optional, Self, SkipSelf} from './metadata';
import {ConstructorProvider, ExistingProvider, FactoryProvider, StaticClassProvider, StaticProvider, ValueProvider} from './provider';
export const SOURCE = '__source';
const _THROW_IF_NOT_FOUND = new Object();
export const THROW_IF_NOT_FOUND = _THROW_IF_NOT_FOUND;
/**
* An InjectionToken that gets the current `Injector` for `createInjector()`-style injectors.
*
* Requesting this token instead of `Injector` allows `StaticInjector` to be tree-shaken from a
* project.
*
* @experimental
*/
export const INJECTOR = new InjectionToken<Injector>('INJECTOR');
export class NullInjector implements Injector {
get(token: any, notFoundValue: any = _THROW_IF_NOT_FOUND): any {
if (notFoundValue === _THROW_IF_NOT_FOUND) {
// Intentionally left behind: With dev tools open the debugger will stop here. There is no
// reason why correctly written application should cause this exception.
// TODO(misko): uncomment the next line once `ngDevMode` works with closure.
// if(ngDevMode) debugger;
throw new Error(`NullInjectorError: No provider for ${stringify(token)}!`);
}
return notFoundValue;
}
}
/**
* Concrete injectors implement this interface.
*
* For more details, see the ["Dependency Injection Guide"](guide/dependency-injection).
*
* @usageNotes
* ### Example
*
* {@example core/di/ts/injector_spec.ts region='Injector'}
*
* `Injector` returns itself when given `Injector` as a token:
*
* {@example core/di/ts/injector_spec.ts region='injectInjector'}
*
*
*/
export abstract class Injector {
static THROW_IF_NOT_FOUND = _THROW_IF_NOT_FOUND;
static NULL: Injector = new NullInjector();
/**
* Retrieves an instance from the injector based on the provided token.
* @returns The instance from the injector if defined, otherwise the `notFoundValue`.
* @throws When the `notFoundValue` is `undefined` or `Injector.THROW_IF_NOT_FOUND`.
*/
abstract get<T>(token: Type<T>|InjectionToken<T>, notFoundValue?: T, flags?: InjectFlags): T;
/**
* @deprecated from v4.0.0 use Type<T> or InjectionToken<T>
* @suppress {duplicate}
*/
abstract get(token: any, notFoundValue?: any): any;
/**
* @deprecated from v5 use the new signature Injector.create(options)
*/
static create(providers: StaticProvider[], parent?: Injector): Injector;
static create(options: {providers: StaticProvider[], parent?: Injector, name?: string}): Injector;
/**
* Create a new Injector which is configure using `StaticProvider`s.
*
* @usageNotes
* ### Example
*
* {@example core/di/ts/provider_spec.ts region='ConstructorProvider'}
*/
static create(
options: StaticProvider[]|{providers: StaticProvider[], parent?: Injector, name?: string},
parent?: Injector): Injector {
if (Array.isArray(options)) {
return new StaticInjector(options, parent);
} else {
return new StaticInjector(options.providers, options.parent, options.name || null);
}
}
static ngInjectableDef = defineInjectable({
providedIn: 'any' as any,
factory: () => inject(INJECTOR),
});
}
const IDENT = function<T>(value: T): T {
return value;
};
const EMPTY = <any[]>[];
const CIRCULAR = IDENT;
const MULTI_PROVIDER_FN = function(): any[] {
return Array.prototype.slice.call(arguments);
};
export const USE_VALUE =
getClosureSafeProperty<ValueProvider>({provide: String, useValue: getClosureSafeProperty});
const NG_TOKEN_PATH = 'ngTokenPath';
const NG_TEMP_TOKEN_PATH = 'ngTempTokenPath';
const enum OptionFlags {
Optional = 1 << 0,
CheckSelf = 1 << 1,
CheckParent = 1 << 2,
Default = CheckSelf | CheckParent
}
const NULL_INJECTOR = Injector.NULL;
const NEW_LINE = /\n/gm;
const NO_NEW_LINE = 'ɵ';
export class StaticInjector implements Injector {
readonly parent: Injector;
readonly source: string|null;
private _records: Map<any, Record>;
constructor(
providers: StaticProvider[], parent: Injector = NULL_INJECTOR, source: string|null = null) {
this.parent = parent;
this.source = source;
const records = this._records = new Map<any, Record>();
records.set(
Injector, <Record>{token: Injector, fn: IDENT, deps: EMPTY, value: this, useNew: false});
records.set(
INJECTOR, <Record>{token: INJECTOR, fn: IDENT, deps: EMPTY, value: this, useNew: false});
recursivelyProcessProviders(records, providers);
}
get<T>(token: Type<T>|InjectionToken<T>, notFoundValue?: T, flags?: InjectFlags): T;
get(token: any, notFoundValue?: any): any;
get(token: any, notFoundValue?: any, flags: InjectFlags = InjectFlags.Default): any {
const record = this._records.get(token);
try {
return tryResolveToken(token, record, this._records, this.parent, notFoundValue, flags);
} catch (e) {
const tokenPath: any[] = e[NG_TEMP_TOKEN_PATH];
if (token[SOURCE]) {
tokenPath.unshift(token[SOURCE]);
}
e.message = formatError('\n' + e.message, tokenPath, this.source);
e[NG_TOKEN_PATH] = tokenPath;
e[NG_TEMP_TOKEN_PATH] = null;
throw e;
}
}
toString() {
const tokens = <string[]>[], records = this._records;
records.forEach((v, token) => tokens.push(stringify(token)));
return `StaticInjector[${tokens.join(', ')}]`;
}
}
type SupportedProvider =
ValueProvider | ExistingProvider | StaticClassProvider | ConstructorProvider | FactoryProvider;
interface Record {
fn: Function;
useNew: boolean;
deps: DependencyRecord[];
value: any;
}
interface DependencyRecord {
token: any;
options: number;
}
type TokenPath = Array<any>;
function resolveProvider(provider: SupportedProvider): Record {
const deps = computeDeps(provider);
let fn: Function = IDENT;
let value: any = EMPTY;
let useNew: boolean = false;
let provide = resolveForwardRef(provider.provide);
if (USE_VALUE in provider) {
// We need to use USE_VALUE in provider since provider.useValue could be defined as undefined.
value = (provider as ValueProvider).useValue;
} else if ((provider as FactoryProvider).useFactory) {
fn = (provider as FactoryProvider).useFactory;
} else if ((provider as ExistingProvider).useExisting) {
// Just use IDENT
} else if ((provider as StaticClassProvider).useClass) {
useNew = true;
fn = resolveForwardRef((provider as StaticClassProvider).useClass);
} else if (typeof provide == 'function') {
useNew = true;
fn = provide;
} else {
throw staticError(
'StaticProvider does not have [useValue|useFactory|useExisting|useClass] or [provide] is not newable',
provider);
}
return {deps, fn, useNew, value};
}
function multiProviderMixError(token: any) {
return staticError('Cannot mix multi providers and regular providers', token);
}
function recursivelyProcessProviders(records: Map<any, Record>, provider: StaticProvider) {
if (provider) {
provider = resolveForwardRef(provider);
if (provider instanceof Array) {
// if we have an array recurse into the array
for (let i = 0; i < provider.length; i++) {
recursivelyProcessProviders(records, provider[i]);
}
} else if (typeof provider === 'function') {
// Functions were supported in ReflectiveInjector, but are not here. For safety give useful
// error messages
throw staticError('Function/Class not supported', provider);
} else if (provider && typeof provider === 'object' && provider.provide) {
// At this point we have what looks like a provider: {provide: ?, ....}
let token = resolveForwardRef(provider.provide);
const resolvedProvider = resolveProvider(provider);
if (provider.multi === true) {
// This is a multi provider.
let multiProvider: Record|undefined = records.get(token);
if (multiProvider) {
if (multiProvider.fn !== MULTI_PROVIDER_FN) {
throw multiProviderMixError(token);
}
} else {
// Create a placeholder factory which will look up the constituents of the multi provider.
records.set(token, multiProvider = <Record>{
token: provider.provide,
deps: [],
useNew: false,
fn: MULTI_PROVIDER_FN,
value: EMPTY
});
}
// Treat the provider as the token.
token = provider;
multiProvider.deps.push({token, options: OptionFlags.Default});
}
const record = records.get(token);
if (record && record.fn == MULTI_PROVIDER_FN) {
throw multiProviderMixError(token);
}
records.set(token, resolvedProvider);
} else {
throw staticError('Unexpected provider', provider);
}
}
}
function tryResolveToken(
token: any, record: Record | undefined, records: Map<any, Record>, parent: Injector,
notFoundValue: any, flags: InjectFlags): any {
try {
return resolveToken(token, record, records, parent, notFoundValue, flags);
} catch (e) {
// ensure that 'e' is of type Error.
if (!(e instanceof Error)) {
e = new Error(e);
}
const path: any[] = e[NG_TEMP_TOKEN_PATH] = e[NG_TEMP_TOKEN_PATH] || [];
path.unshift(token);
if (record && record.value == CIRCULAR) {
// Reset the Circular flag.
record.value = EMPTY;
}
throw e;
}
}
function resolveToken(
token: any, record: Record | undefined, records: Map<any, Record>, parent: Injector,
notFoundValue: any, flags: InjectFlags): any {
let value;
if (record && !(flags & InjectFlags.SkipSelf)) {
// If we don't have a record, this implies that we don't own the provider hence don't know how
// to resolve it.
value = record.value;
if (value == CIRCULAR) {
throw Error(NO_NEW_LINE + 'Circular dependency');
} else if (value === EMPTY) {
record.value = CIRCULAR;
let obj = undefined;
let useNew = record.useNew;
let fn = record.fn;
let depRecords = record.deps;
let deps = EMPTY;
if (depRecords.length) {
deps = [];
for (let i = 0; i < depRecords.length; i++) {
const depRecord: DependencyRecord = depRecords[i];
const options = depRecord.options;
const childRecord =
options & OptionFlags.CheckSelf ? records.get(depRecord.token) : undefined;
deps.push(tryResolveToken(
// Current Token to resolve
depRecord.token,
// A record which describes how to resolve the token.
// If undefined, this means we don't have such a record
childRecord,
// Other records we know about.
records,
// If we don't know how to resolve dependency and we should not check parent for it,
// than pass in Null injector.
!childRecord && !(options & OptionFlags.CheckParent) ? NULL_INJECTOR : parent,
options & OptionFlags.Optional ? null : Injector.THROW_IF_NOT_FOUND,
InjectFlags.Default));
}
}
record.value = value = useNew ? new (fn as any)(...deps) : fn.apply(obj, deps);
}
} else if (!(flags & InjectFlags.Self)) {
value = parent.get(token, notFoundValue, InjectFlags.Default);
}
return value;
}
function computeDeps(provider: StaticProvider): DependencyRecord[] {
let deps: DependencyRecord[] = EMPTY;
const providerDeps: any[] =
(provider as ExistingProvider & StaticClassProvider & ConstructorProvider).deps;
if (providerDeps && providerDeps.length) {
deps = [];
for (let i = 0; i < providerDeps.length; i++) {
let options = OptionFlags.Default;
let token = resolveForwardRef(providerDeps[i]);
if (token instanceof Array) {
for (let j = 0, annotations = token; j < annotations.length; j++) {
const annotation = annotations[j];
if (annotation instanceof Optional || annotation == Optional) {
options = options | OptionFlags.Optional;
} else if (annotation instanceof SkipSelf || annotation == SkipSelf) {
options = options & ~OptionFlags.CheckSelf;
} else if (annotation instanceof Self || annotation == Self) {
options = options & ~OptionFlags.CheckParent;
} else if (annotation instanceof Inject) {
token = (annotation as Inject).token;
} else {
token = resolveForwardRef(annotation);
}
}
}
deps.push({token, options});
}
} else if ((provider as ExistingProvider).useExisting) {
const token = resolveForwardRef((provider as ExistingProvider).useExisting);
deps = [{token, options: OptionFlags.Default}];
} else if (!providerDeps && !(USE_VALUE in provider)) {
// useValue & useExisting are the only ones which are exempt from deps all others need it.
throw staticError('\'deps\' required', provider);
}
return deps;
}
function formatError(text: string, obj: any, source: string | null = null): string {
text = text && text.charAt(0) === '\n' && text.charAt(1) == NO_NEW_LINE ? text.substr(2) : text;
let context = stringify(obj);
if (obj instanceof Array) {
context = obj.map(stringify).join(' -> ');
} else if (typeof obj === 'object') {
let parts = <string[]>[];
for (let key in obj) {
if (obj.hasOwnProperty(key)) {
let value = obj[key];
parts.push(
key + ':' + (typeof value === 'string' ? JSON.stringify(value) : stringify(value)));
}
}
context = `{${parts.join(', ')}}`;
}
return `StaticInjectorError${source ? '(' + source + ')' : ''}[${context}]: ${text.replace(NEW_LINE, '\n ')}`;
}
function staticError(text: string, obj: any): Error {
return new Error(formatError(text, obj));
}
/**
* Injection flags for DI.
*/
export const enum InjectFlags {
Default = 0b0000,
/**
* Specifies that an injector should retrieve a dependency from any injector until reaching the
* host element of the current component. (Only used with Element Injector)
*/
Host = 0b0001,
/** Don't descend into ancestors of the node requesting injection. */
Self = 0b0010,
/** Skip the node that is requesting injection. */
SkipSelf = 0b0100,
/** Inject `defaultValue` instead if token not found. */
Optional = 0b1000,
}
/**
* Current injector value used by `inject`.
* - `undefined`: it is an error to call `inject`
* - `null`: `inject` can be called but there is no injector (limp-mode).
* - Injector instance: Use the injector for resolution.
*/
let _currentInjector: Injector|undefined|null = undefined;
export function setCurrentInjector(injector: Injector | null | undefined): Injector|undefined|null {
const former = _currentInjector;
_currentInjector = injector;
return former;
}
/**
* Injects a token from the currently active injector.
*
* This function must be used in the context of a factory function such as one defined for an
* `InjectionToken`, and will throw an error if not called from such a context.
*
* @usageNotes
* ### Example
*
* {@example core/di/ts/injector_spec.ts region='ShakeableInjectionToken'}
*
* Within such a factory function `inject` is utilized to request injection of a dependency, instead
* of providing an additional array of dependencies as was common to do with `useFactory` providers.
* `inject` is faster and more type-safe.
*
* @experimental
*/
export function inject<T>(token: Type<T>| InjectionToken<T>): T;
export function inject<T>(token: Type<T>| InjectionToken<T>, flags?: InjectFlags): T|null;
export function inject<T>(token: Type<T>| InjectionToken<T>, flags = InjectFlags.Default): T|null {
if (_currentInjector === undefined) {
throw new Error(`inject() must be called from an injection context`);
} else if (_currentInjector === null) {
const injectableDef: InjectableDef<T>|null = getInjectableDef(token);
if (injectableDef && injectableDef.providedIn == 'root') {
return injectableDef.value === undefined ? injectableDef.value = injectableDef.factory() :
injectableDef.value;
}
if (flags & InjectFlags.Optional) return null;
throw new Error(`Injector: NOT_FOUND [${stringify(token)}]`);
} else {
return _currentInjector.get(token, flags & InjectFlags.Optional ? null : undefined, flags);
}
}
export function injectArgs(types: (Type<any>| InjectionToken<any>| any[])[]): any[] {
const args: any[] = [];
for (let i = 0; i < types.length; i++) {
const arg = types[i];
if (Array.isArray(arg)) {
if (arg.length === 0) {
throw new Error('Arguments array must have arguments.');
}
let type: Type<any>|undefined = undefined;
let flags: InjectFlags = InjectFlags.Default;
for (let j = 0; j < arg.length; j++) {
const meta = arg[j];
if (meta instanceof Optional || meta.ngMetadataName === 'Optional') {
flags |= InjectFlags.Optional;
} else if (meta instanceof SkipSelf || meta.ngMetadataName === 'SkipSelf') {
flags |= InjectFlags.SkipSelf;
} else if (meta instanceof Self || meta.ngMetadataName === 'Self') {
flags |= InjectFlags.Self;
} else if (meta instanceof Inject) {
type = meta.token;
} else {
type = meta;
}
}
args.push(inject(type !, flags));
} else {
args.push(inject(arg));
}
}
return args;
}