- #704 part 2 of 2
- change `@Html.Id()` to sanitize return value; was identical to `@Html.Name()`
Copied `TagBuilder.CreateSanitizedId()` and `TagBuilder.Html401IdUtil` from MVC 5.2
- except this `CreateSanitizedId()` returns a valid identifier if first `char` is not a letter
- e.g. "[0].Name"
nits:
- expand variable names, use lots of `var`, put `public` members first
- add doc comments for `CreateSanitizedId()`
Note users will be able to apply different sanitization once we fix#1188.
- #874 lines 3, 4, and 6
- correct `Value()` to treat a `null` expression name the same as `string.Empty`
- add missing `[NotNull]` attributes in `EditorExtensions` and for `GenerateIdFromName()`
- consistently pass `null` for default expression names to the helpers
- for example, from extension methods
- add test cases using `null` for expression name
nits:
- correct summary XML comment for `HtmlHelper` class
- use named parameters and prefer interface (not extension) methods in changed calls
- use `string.Empty` instead of `""` in a few tests