ng-arc

Introduction

Over years of building Angular 1.x projects, and trying out recommended best practices, I came to realize that some things just weren't working, and there was a better way. The following summarizes my observations and new recommended best practices which I have personally used and can vouch for their efficacy in reducing defects and increasing development velocity and maintainability. Comments and PRs are welcome.

Angular, the Good Parts

• Separation of concerns -- html templates, js services.
• track by in ng-repeat. Lack of track by in ng-repeat expressions is the primary source of all complaints about angular performance.
• $scope
  • $scope handles user input and asynchronous events very well. It requires some work ($apply, etc.) to handle non-angular asynchronous events, but this is intuitive and well worth the cost.
• Services
  • Singletons provide easy access to data and shared functionality.
  • No reasoning about instances.
  • No babying object references if all references are fully-qualified.
    • This is a problem you encounter when you write $scope.data = MyService.data in a controller, then later replace MyService.data somewhere else, e.g. after an $http get to update the data).
  • $http
• Directives
  • Declarative reaction to user input events or model updates
• testing; no-fuss methods are provided by Angular 1 to help set up test cases

The less-good parts

• $scope events.
• Angular "Controllers"
  • $scope is the controller in Angular. It reacts to user input or async changes in the data model, binding the UI and data together.
  • Input events should directly trigger logic in well-known and visible services.

Bad practices

• Using event systems. This seriously inhibits predictability and the ability to causes additional bugs, because you don't know who is broadcasting or listening to events.
• Building complicated service hierarchies or relationships.
  • Instead, the relationship should be made obvious in the template. E.g. <div class="username" with-service="{f: 'MyFriends', rp: '$routeParameters'}">{{ f.byUsername[rp.username] }}</div>
• "Components" as replacement for native HTML elements.
  • Directives should very rarely use the element type, opting for augmenting the behavior of native HTML to avoid creating tribal DSLs.

New Best Practices

• A new directive that supports explicitly importing services into angular templates.
• Effective deprecation of "Controllers." Much more often than not, these add a layer of obscurity and end up taking references. This might seem to clean things up, but it creates bugs when the references become stale.