Handle view.query() being invoked when view.el is undefined

[ampersandjs]

Handle view.query() being invoked when view.el is undefined

[wraithgar]

In cases like this we've tended towards a more helpful exception. If you query against a nonexistent el it should still probably throw, but it should throw a specific error like 'this.el not defined'

ETA: This is just my opinion, adding discussion label.

[kamilogorek]

Agree with @wraithgar Querying is only possible on rendered elements or something similar.

[wraithgar]

Just to be clear, the current options are: add the guard to query that already exists in queryAll, or make both throw a descriptive exception if this.el is not defined

[nirrek]

I think having a useful exception thrown is preferable to simply returning an empty array or undefined.

Empty array / undefined should mean that DOM traversal was correctly performed, but there were no matches found.

When el is undefined, you never actually perform a search at all. This will never be the intention of the user, so they should be notified that they are doing something incorrectly.

Possible exception message:
Query cannot be performed as this.el is not defined. Ensure that the view has been rendered.

[wraithgar]

I like that. This would still be a breaking change as anyone currently relying on the guard statement would now be getting an exception thrown.

[pgilad]

^ Added a PR for this. I agree error should be thrown as to be verbose.
Notice:

1. Change queryAll to first throw if this.el doesn't exist, then possibly return [this.el] if !selector.
2. Breaking change for queryAll
3. Test?