An error should be thrown if loading resources failed

[Piotrek Koszuliński]

Based on: #11315.

There are couple of scriptLoader.load usage and none check if request completed. When request failed error should be thrown, so developer knows what happened.

[Olek Nowodziński]

cc

[Marek Lewandowski]

cc

[Jakub Ś]

Problem can be reproduced from CKEditor 3.0 in both CKE 3.x and 4.x

I have however one proposition here taken from Java Frameworks. I think error is unacceptable and we should propose more user friendly approach.

In Java frameworks if some key isn't found then instead of error String is returned e.g. ???lang.somePropertyName???. Editor will load that way and developer will know that for some reason this property is simply not present.

[Olek Nowodziński]

Replying to j.swiderski:

Problem can be reproduced from CKEditor 3.0 in both CKE 3.x and 4.x

I have however one proposition here taken from Java Frameworks. I think error is unacceptable and we should propose more user friendly approach.

In Java frameworks if some key isn't found then instead of error String is returned e.g. ???lang.somePropertyName???. Editor will load that way and developer will know that for some reason this property is simply not present.

While it may sound reasonable in Java, it doesn't make much sense for compressed JS code which is not to be debugged by developers. In my opinion it is quite convenient to log things in case of major failure and, since developer console is our only destination, we should definitely use it.

[Jakub Ś]

My only point is that it is weird not to load whole when e.g. one label is missing. Besides examples where I came in touch with this problem is when developers were playing around (modifying, adding or removing properties) with language files.

Anyway that was just my suggestion. If you think error is better approach here I won't argue. Developer will fix it one way or another.

[Piotrek Koszuliński]

We cannot check and handle every label, every property, every possible way of failure. It's not a heavy Java app. It has to be light and assume that what is required to work was correctly loaded and is complete. So the only thing which we can do is checking if everything is ok in most important points and throw a clear error if isn't.

[Jakub Ś]

Throw error you say - this is where you can handle this, in catch statement. There is no need to handle every possible label but use simple approach -> catch error and return String.

Anyway you will do as you want:)