Allow for module-global view-strategies.

[Alxandr]

Currently I use the following to set the view strategy (view factory factory) of my view model:

import {Router} from 'aurelia-router';

import view from './app.html!';

export class App {
  static inject() { return [Router]; }
  constructor(router) {
    this.router = router;
    this.router.configure(config => {
      config.title = 'Application Title';
      config.map([
        { route: 'blog',      moduleId: './blog/routes/index', nav: true, title: 'Blog' },
        { route: '',          moduleId: './redirect', redirect: '/blog' }
      ]);
    });
  }

  getViewStrategy() {
    return view;
  }
}

I would really like it though, if I could do something like this instead

import {Router} from 'aurelia-router';

export {view} from './app.html!';

export class App {
  static inject() { return [Router]; }
  constructor(router) {
    this.router = router;
    this.router.configure(config => {
      config.title = 'Application Title';
      config.map([
        { route: 'blog',      moduleId: './blog/routes/index', nav: true, title: 'Blog' },
        { route: '',          moduleId: './redirect', redirect: '/blog' }
      ]);
    });
  }
}

This basically creates a property on the module, named view, which acts as a module-global view factory factory.

[Craga89]

This could currently be done by overriding the ViewStrategy classes getDefault method:

import {ViewStrategy} from 'aurelia-templating';
import {Metadata, Origin} from 'aurelia-metadata';

ViewStrategy.getDefault = function(target) {
     var strategy, annotation;

    if(typeof target !== 'function'){
      target = target.constructor;
    }

    annotation = Origin.get(target);
    strategy = Metadata.on(target).first(ViewStrategy);

    if(!strategy){
      if(!annotation){
        throw new Error('Cannot determinte default view strategy for object.', target);
      }
      // Override this part
      strategy = new MyCustomViewStrategy(annotation.moduleId);
    }
    else if(annotation){
      strategy.moduleId = annotation.moduleId;
    }

    return strategy;
}

Though it would be nice if this method hooked into some kind of global config option like defaultViewStrategy that we could override, rather than re-declaring the whole method