Inconsistent handling of invalid initial ngModel values

[Narretz]

An ngModelController created with an invalid inital value from scope behaves differently depending on input type:

http://jsfiddle.net/PK3QH/27/

Type	invalid model	view	behavior	error	good
text	{}	[object Object]	calls toString	correctly set	⁉️
url	'notanurl'	notanurl	calls toString	correctly set	✅
number	'notanumber'	(empty) ❌	throws if model is not type number ⁉️	no errors are set because of exception ❌	❌
number+min=5	3	3	^	correctly set	✅
date	'notadate'	(empty) ❌	expects a date and uses the date filte, else returns nothing	required set	❌
date	new Date('123456')	0NaN-NaN-NaN	^	$error.date is not set ❌	❌

I think we should always try to set the $viewValue to something. This is important if you have server-side data that may be invalid.
So number and date should not discard invalid values. If we pass garbage to the validators, the correct errors will be set.
Regarding calling toString on text-based input. I think that's okay as you will rarely set an object to a model when you know it'll be displayed in an input. But we should do "the right thing" and try to format values that are good enough, so in short:

• number should not throw and call toString regardless
• date should return call toString if not a Date object
• date should also get the bug fixed where NaN gets output

I'll think I'll be able to throw a PR together over the weekend.

[caitp]

You won't be able to fix a number of these that you're claiming to be "not good" (otherwise we'd have inconsistencies between user specified values and model-specified values)

[Narretz]

I admit, I haven't looked into it. Do you mean because of native validators?

[caitp]

You can't set a date or number input's values to something which doesn't fit the date or number parsing rules (I'm pretty sure that's the end result of what we do in setViewValue) http://jsfiddle.net/egedyh1v/

[Narretz]

Ah, I see what you mean. However, I think I can improve the handling a little bit.
And the last entry, the date, that looks like a bug in the date filter.

[Narretz]

Well, yeah I see what you mean. I think the code needs some comments why we're doing this.