AoT编译的标记化 [英] Tokenizing for AoT compilation

问题描述

我一直对 JIT之间的不一致有一些疑问和AoT编译器。最近困扰我的错误是错误：无法解析IndexedDBCache的所有参数。 IndexedDBCache是​​一种依赖于 string 参数的服务：

请注意，当我删除受保护属性！

  // indexeddb-cache.ts 
从 @ angular / core导入{可注入}； 
 
 @ Injectable（）
导出类IndexedDBCache {
构造函数（受保护的数据库名称：字符串）{} 
} 
  

我正在使用一家工厂提供该服务的版本：

  // test-api.cache.factory.ts 
从'../indexeddb-cache/indexeddb-cache'导入{IndexedDBCache}； 
 
导出函数testIndexedDBCacheFactory（）{返回新的IndexedDBCache（'test'）; } 
 
 // test-api.cache.ts 
从 @ angular / core导入{InjectionToken，Provider}； 
从 ../indexeddb-cache/indexeddb-cache导入{IndexedDBCache}; 
从 ./test-api.cache.factory导入{testIndexedDBCacheFactory； 
 
 export const testIndexedDBCache = new InjectionToken< IndexedDBCache>（'testIndexedDBCache'）; 
 
导出let testIndexedDBCacheProvider：提供者= {
提供：testIndexedDBCache，
 useFactory：testIndexedDBCacheFactory 
}; 
  

注意：这些文件必须根据 func-in-providers-useFactory 和 arrow-function-exports -不要问我为什么= /

现在，AoT编译器根本不喜欢此 string 参数。我已经调查了这个问题，但只能找到对 OpaqueToken 的引用（现在已被描述并替换为 InjectionToken< string> ）。我的代码现在显示为：

  // test-api.cache.factory.ts 
从 @ angular / core导入{InjectionToken}； 
从 ../indexeddb-cache/indexeddb-cache导入{IndexedDBCache}; 
 
 const testIndexedDBCacheFactoryToken = new InjectionToken< string>（ test）; 
导出函数testIndexedDBCacheFactory（）{返回新的IndexedDBCache（testIndexedDBCacheFactoryToken）; } 
  

显然，由于构造函数只允许使用字符串，因此无法编译参数。我没有足够的有关InjectionTokens或AoT问题的知识来解决此问题-任何人都建议一个可行的结构？

我的代码中有更多上下文并可以在 angular / angular＃17295 中找到问题。。 p>

---

我尝试过的事情：

1. 删除受保护的访问修饰符> 仍然存在完全相同的错误


2. 删除字符串参数> 不是一个选项-它定义了服务


3. 在工厂中用 InjectionToken< string> 替换字符串参数> InjectionToken不是合适的参数

解决方案

对眼前问题的误解。要分解的类本身不是服务，因此不需要 @Injectable 属性。有关详细信息，请参见创建与AoT兼容的服务工厂

I've been having some issues with the inconsistencies between the JIT and AoT compilers. The most recent error that has stumped me was Error: Can't resolve all parameters for IndexedDBCache. IndexedDBCache is a service that depends on a string parameter:

Please note this issue also arises when I remove the 'protected' property!

// indexeddb-cache.ts
import { Injectable } from '@angular/core';

@Injectable()
export class IndexedDBCache {
  constructor(protected databaseName : string) {}
}

I'm using a factory to provide versions of the service:

// test-api.cache.factory.ts
import { IndexedDBCache } from '../indexeddb-cache/indexeddb-cache';

export function testIndexedDBCacheFactory() { return new IndexedDBCache('test'); }

// test-api.cache.ts
import { InjectionToken, Provider } from '@angular/core';
import { IndexedDBCache } from '../indexeddb-cache/indexeddb-cache';
import { testIndexedDBCacheFactory } from './test-api.cache.factory';

export const testIndexedDBCache = new InjectionToken<IndexedDBCache>('testIndexedDBCache');

export let testIndexedDBCacheProvider : Provider = {
  provide: testIndexedDBCache,
  useFactory: testIndexedDBCacheFactory
};

Note : These files have to be split according to func-in-providers-useFactory and arrow-function-exports - don't ask me why =/

Now the AoT compiler doesn't like this string paramter at all. I've looked into the issue but could only find reference to OpaqueToken (now depricated and replaced by InjectionToken<string>). My code would now read:

// test-api.cache.factory.ts
import { InjectionToken } from '@angular/core';
import { IndexedDBCache } from '../indexeddb-cache/indexeddb-cache';

const testIndexedDBCacheFactoryToken = new InjectionToken<string>('test');
export function testIndexedDBCacheFactory() { return new IndexedDBCache(testIndexedDBCacheFactoryToken); }

Obviously this is not compiling as the constructor would only allow for a string parameter. I don't have enough knowledge about InjectionTokens or the AoT issue at hand to solve this - anyone have a suggestion for a construct that would work?

More context on my code and issue to be found at angular/angular#17295.

---

Things I've tried:

1. Removing the protected access modifier > Exact same error persists
2. Removing the string parameter > Not an option - it defines the service
3. Replacing the string parameter in the factory with an InjectionToken<string> > An InjectionToken is not a suitable parameter

解决方案

There was a misunderstanding of the issue at hand. The classes to be factoried are not services themselves and as such do not need the @Injectable property. More detail to be found at Creating AoT compatible Service Factories

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