use interface instead of abstract class MissingTranslationHandler

[ngx-translate]

use interface instead of abstract class MissingTranslationHandler

[ocombe]

You can implement an abstract class as well. How is it more flexible with an interface ?

[ribizli]

In a class you can have only one superclass but more implemented
interfaces. It's a minor thing, anyway.

On Mon, Feb 29, 2016 at 11:23 AM, Olivier Combe [email protected]
wrote:

You can implement an abstract class as well. How is it more flexible with
an interface ?

—
Reply to this email directly or view it on GitHub
#48 (comment)
.

[ocombe]

Hmm good to know, but can you write an interface that implements the abstract class and then implement this interface ?

[ribizli]

I'd replace the abstract class with interface.

On Mon, Feb 29, 2016 at 11:35 AM, Olivier Combe [email protected]
wrote:

Hmm good to know, but can you write an interface that implements the
abstract class and then implement this interface ?

—
Reply to this email directly or view it on GitHub
#48 (comment)
.

[DanielSchuech]

I would agree in that case the the interface would be the better choice. I didn´t thought about this while implementing this feature.

Is your design maybe to complex? A class should only attend one responsibility to fulfill the Single Responsibility Principle. Maybe it would be better to devide your behabiour into different classes and MissingTranslationHandler inherit from just oneclass. That would be maybe better maintainable. But thats jsut an idee because I don`t know your use cases.

[ribizli]

I've just stumbled into this thing when I was reading the source. For me the rule of thumb is to use interface if I don't need to deliver default functionality. Since the abstract class don't have any implemented feature, it could be cleaner to be a simple interface.

The test implementation shows also, that this abstract class is anyway used as interface only:

class Missing implements MissingTranslationHandler

[DanielSchuech]

@ribizli Yeah. As mentioned I agree with you.

[ocombe]

Yup good points, I'll change that for the next release

[ribizli]

I can prepare a PR for this and also create an NG2_TRANSLATE_PROVIDER for the default configuration. This is the proper angular2 way (like HTTP_PROVIDERS).

[ocombe]

ah yes good idea, thanks