- Not all `TagHelper`s have unbound HTML attributes or any attributes at all. A great example of this is MVC's input `TagHelper` which usually takes the format of `<input asp-for="..." />`. By lazily initializing we don't build extra attribute lists where not needed.
- Moved `TagHelperContext` and `TagHelperOutput` creation to CreateX methods on `TagHelperExecutionContext`.
#604
- Remove a lot of the ugly generic work done in `TagHelperAttributeList`/`ReadOnlyTagHelperAttributeList`.
- Removed error cases where we'd check on addition of `TagHelperAttribute`s that their `name` was not `null`. This was due to the pre-existing `string` indexer for `TagHelperAttributeList`. It no longer sets `TagHelperAttribute`s directly, instead it's `[key] = value` (instead of `[key] = new TagHelperAttribute(...))`.
- Updated tests to account for new immutability/string indexer format.
- Removed copy ctor from `TagHelperAttribute` since its immutability kills the value.
- Changed `ReadOnlyTagHelperAttributeList` to inherit from `ReadOnlyCollection`
#604
This change 'flattens' a TagHelperOutput when writing it out to an
HtmlTextWriter. This is a beneficial perf change because more often than
not the thing being written to is a ViewBuffer in Razor, which uses pooled
memory. This allows us to 'join' islands of pooled ViewBuffer memory back
into the main buffer instead of keeping them wrapped up in a
TagHelperOutput or TagHelperContent.
N. Taylor Mullen
Kiran Challa
Ryan Nowak