Angular 2 Ahead-of-Time compiler: must I make all

2019-01-11 11:09发布

问题:

Angular 2 rc 6, typescript 2, node 4.5.0, npm 2.15.9 on Windows 7

I'm trying to move from Just-in-Time to Ahead-of-Time compilation and I'm relying on these resources:

  • Angular 2 - Ahead-of-time compilation how to
  • https://github.com/angular/angular/tree/master/modules/@angular/compiler-cli#angular-template-compiler

I understand that I need to run the compiler ngc to generate ngfactory.ts files, and that I need to change main.ts to use platformBrowser instead of platformBrowserDynamic to bootstrap. I've hit a roadblock though and don't know how to proceed.

1. I've confirmed that the App runs without errors using Just-in-Time compilation. My main.ts is:

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

2. I clear all my app files from my production folder, but keep 3rd party libraries (eg: Angular 2, Angular 2 Material)

3. I run "node_modules/.bin/ngc" -p ./ This runs with no output to the console. I see an .ngfactory.ts file for each of my .ts components and modules. I also see a .css.shim.ts file for each of my .css that held component styles. In addition, .js and .js.map files have been transpiled and placed in the production directory

4. If I try to run the app at this point, I see 404 not found errors for all the .html files that held component templates

5. I manually move all template files (.html) to production dir and run the App. It runs fine, but it still uses Just-in-Time compilation (255 requests, including compiler.umd.js)

6. I change my main.ts to:

enableProdMode();
platformBrowser().bootstrapModuleFactory(AppModuleNgFactory);

On its own, this makes no difference since the new code has not been compiled. However, I don't know what to do from here.

Should I run ngc again? If so I get lots of errors of the type:

Error at C:/path/to/notify.component.ngfactory.ts:113:41: Property 'visible' is private and only accessible within class 'NotifyComponent'
... (many more like that with lots of properties from lots of components)
Compilation failed

Does using AoT compilation mean that I must make all my class properties public? Am I missing a step?

回答1:

For a given component all its members (methods, properties) accessed by its template must be public in the ahead-of-time compilation scenario. This is due to the fact that a template is turned into a TS class. A generated class and a component are 2 separate classes now and you can't access private members cross-class.

In short: you can't access private members in your templates if you want to use ahead-of-time compilation.



回答2:

So is too, in Final release of Angular 2 whit Ionic2 RC1

A workaround for Fields could be to use getters without setters

protected _myField: any;

get myField(): any { 
  return this._myField; 
}

You can also see other JiT to AoT considerations to adapt your code in this blog of Isaac Mann

  1. const lambda => export function
  2. default export => named export
  3. private, protected accessors should be changed to public for any members accessed from template
  4. dynamic component template => static template
  5. moduleId should be set on components with templateUrl