This change replaces the parsing of HTML that we perform during the code
generation phase, which parsing of HTML during the IR lowering phase.
The main benefit of this change is that the structure of the HTML is
reflected in the IR tree, allowing us to do more more advance
transformations.
As an example, see how the the handling of `<script>` tags is now a
separate pass.
As an aside from this I also redesigned the structure of component IR
nodes to match the new HTML element nodes. Passes are now more easily
aware of the nodes they are expected to handle and are more easily aware
of the difference between a component and element. This still isn't as
clean as I would like, but I think it's a reasonable improvement.
Another benefit of this is that the code generation is much simpler and
requires much less bookkeeping and statefulness.
This change removes support for the old syntax used for event handlers
and two-way binding.
See the relevant issues for details on the new features and
improvements:
bind https://github.com/aspnet/Blazor/issues/409
event handlers https://github.com/aspnet/Blazor/issues/503
Along with this change we've removed a few additional things Blazor
could do that aren't part of Razor's usual syntax.
----
The features that was used to make something like:
```
<button @onclick(...) />
```
is an expression that's embedded in a an element's attribute. This
feature might be useful in the future if we want to support 'splatting'
arbitrary attributes into a tag, but the runtime support for this isn't
accessible outside the Blazor core.
----
The features that implement:
```
<button onclick=@{ } />
```
have been removed in favor of a better design for lambdas, method group
conversions and other things for event handler attributes.
use `<button onclick=@(x => ...} />` instead.
We think is a better approach in general, because we want the app
developer to write and see the parameter list.
----
Both syntactic features that have been removed have dedicated error
messages in the compiler. If you're porting old code it should help you
figure out what to do.
Adds a little more use of Razor extensibility.
Razor is a plugin model, so we can't be the 'first mover' for initiating
compilation in the build tools and IDE.
Reorganizes tests and fills out more reusable test infrastructure for
Razor-driven testing.
Adds tests for declaration-only configuration.
Ryan Nowak
Steve Sanderson