angular-cn/packages/compiler/src/injectable_compiler_2.ts

128 lines
4.2 KiB
TypeScript

/**
* @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 {Identifiers} from './identifiers';
import * as o from './output/output_ast';
import {R3DependencyMetadata, R3FactoryDelegateType, R3FactoryMetadata, R3FactoryTarget, compileFactoryFunction} from './render3/r3_factory';
import {mapToMapExpression, typeWithParameters} from './render3/util';
export interface InjectableDef {
expression: o.Expression;
type: o.Type;
statements: o.Statement[];
}
export interface R3InjectableMetadata {
name: string;
type: o.Expression;
internalType: o.Expression;
typeArgumentCount: number;
providedIn: o.Expression;
useClass?: o.Expression;
useFactory?: o.Expression;
useExisting?: o.Expression;
useValue?: o.Expression;
userDeps?: R3DependencyMetadata[];
}
export function compileInjectable(meta: R3InjectableMetadata): InjectableDef {
let result: {factory: o.Expression, statements: o.Statement[]}|null = null;
const factoryMeta: R3FactoryMetadata = {
name: meta.name,
type: meta.type,
internalType: meta.internalType,
typeArgumentCount: meta.typeArgumentCount,
deps: [],
injectFn: Identifiers.inject,
target: R3FactoryTarget.Injectable,
};
if (meta.useClass !== undefined) {
// meta.useClass has two modes of operation. Either deps are specified, in which case `new` is
// used to instantiate the class with dependencies injected, or deps are not specified and
// the factory of the class is used to instantiate it.
//
// A special case exists for useClass: Type where Type is the injectable type itself and no
// deps are specified, in which case 'useClass' is effectively ignored.
const useClassOnSelf = meta.useClass.isEquivalent(meta.internalType);
let deps: R3DependencyMetadata[]|undefined = undefined;
if (meta.userDeps !== undefined) {
deps = meta.userDeps;
}
if (deps !== undefined) {
// factory: () => new meta.useClass(...deps)
result = compileFactoryFunction({
...factoryMeta,
delegate: meta.useClass,
delegateDeps: deps,
delegateType: R3FactoryDelegateType.Class,
});
} else if (useClassOnSelf) {
result = compileFactoryFunction(factoryMeta);
} else {
result = delegateToFactory(meta.useClass);
}
} else if (meta.useFactory !== undefined) {
if (meta.userDeps !== undefined) {
result = compileFactoryFunction({
...factoryMeta,
delegate: meta.useFactory,
delegateDeps: meta.userDeps || [],
delegateType: R3FactoryDelegateType.Function,
});
} else {
result = {
statements: [],
factory: o.fn([], [new o.ReturnStatement(meta.useFactory.callFn([]))])
};
}
} else if (meta.useValue !== undefined) {
// Note: it's safe to use `meta.useValue` instead of the `USE_VALUE in meta` check used for
// client code because meta.useValue is an Expression which will be defined even if the actual
// value is undefined.
result = compileFactoryFunction({
...factoryMeta,
expression: meta.useValue,
});
} else if (meta.useExisting !== undefined) {
// useExisting is an `inject` call on the existing token.
result = compileFactoryFunction({
...factoryMeta,
expression: o.importExpr(Identifiers.inject).callFn([meta.useExisting]),
});
} else {
result = delegateToFactory(meta.internalType);
}
const token = meta.internalType;
const providedIn = meta.providedIn;
const expression = o.importExpr(Identifiers.ɵɵdefineInjectable).callFn([mapToMapExpression(
{token, factory: result.factory, providedIn})]);
const type = new o.ExpressionType(o.importExpr(
Identifiers.InjectableDef, [typeWithParameters(meta.type, meta.typeArgumentCount)]));
return {
expression,
type,
statements: result.statements,
};
}
function delegateToFactory(type: o.Expression) {
return {
statements: [],
// () => type.ɵfac(t)
factory: o.fn([new o.FnParam('t', o.DYNAMIC_TYPE)], [new o.ReturnStatement(type.callMethod(
'ɵfac', [o.variable('t')]))])
};
}