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.
- #643 part 1
- change is viral and requires an update to `RazorPage.StartTagHelperWritingScope()`
- memoize `GetChildContentAsync()` per-encoder
- update generation tests to match and to test new behaviour
- note `HtmlEncoder`s used elsewhere e.g. in other `RazorPage` instances are unaffected
Add `NullHtmlEncoder`
Nits:
- generally clean up affected doc comments and make them more consistent
- remove unused `using`s in files I had open
Changing to IReadOnlyList since we always want to support indexing.
Replacing ToArray() with non-linq when needed, and with a static
EmptyArray when not needed.
Eliminates 50mb of list copies.
- Roslyn currently has an issue where too large of strings result in out of memory exceptions at compile time. To combat this I broke down literal strings into 1024 length pieces each resulting in their own `WriteLiteral`/`WriteLiteralTo` calls. The 1024 number corresponds directly with MVCs response string buffer.
- Added tests to validate large string rendering.
#614
- Prior to this change we'd hit the disk every time we'd create a `TagHelperDesignTimeDescriptor` to locate an assemblies XML files.
- Did not want to tie the XML cache to a static member in-case a user updates their XML information between parses. Therefore, changed `TagHelperDescriptorFactory` and `TagHelperDesignTimeDescriptorFactory` to no longer be static.
- Put the same `TagHeleprDescriptorFactory` extensibility point as we had for its counterpart `TagHelperTypeResolver` to stay consistent. This involved making `CreateDescriptors` virtual and allowing it to be provided in the `TagHelperDescriptorResolver` constructor.
#630
- Updated existing tests and added a new case to understand `@section {....` scenarios.
- Instead of trying to guess 1 character prior to EOF decided to log error on opening brace since we know its position. Updated error to account for change in location.
#625
- This allows users to write `TagHelperOutput` directly to an `IHtmlContent` accepting `TextWriter`.
- This also enables us to inspect backing fields for all of the various contents to lazily initialize them.
#358
This change significantly reduces the amount of string and List<ISymbol>
allocations that occur during compilation by changing the way
LiteralChunks are combined.
This is a low impact fix that addresses the performance issue, the design
issues that caused it still exist.
The problem here lies in what Razor fundamentally does - it parses HTML/C#
into tokens, and then combines them back into 'chunks' a representation
friendly to code generation. When presenting with a large block of static
HTML, Razor parses it into individual HTML tokens, and then tries to join
them in back into a single chunk for rendering. Due to details of Razor's
representation of chunks/tokens, the process of combining literals is too
expensive.
Mainly, what's done here is to not try to combine instances of
LiteralChunk. The process of merging them is too expensive and requires
lots of interm List<ISymbol> and string allocations.
Instead we produce a new 'chunk' ParentLiteralChunk, which doesn't do so
much up-front computing. Various pieces of the code that deal with
LiteralChunk need to be updated to deal with ParentLiteralChunk also,
which is the bulk of the changes here.
Note that we still have the potential for LOH allocations to occur during
codegen, but it's likely to occur O(1) for each large block of HTML
instead of O(N) as it did in the old code.
- Updated .cshtml files to not provide quotes for the various `TagHelper` directives.
- Updated `TagHelper` directive parsing tests. This also involved removing several tests that expected errors which no longer occur since we don't have to ensure quotes are balanced.
- Updated line mappings which significantly changed due to us no longer generating line pragmas at design time for `TagHelper` directives.
#561
- Template attributes should be of type `Func<TextWriter, Task>`. We weren't generating an `async` lambda for attributes prior to this change resulting in a compilation failure when used at runtime and the inability to `@await` code (unless a user returns some sort of `Task`).
- Updated code generation files to reflect the new code generation behavior.
#594
- The using statements had a chance to conflict with user code. Removed them and changed the default configured type names to be `global::` full name based.
- Updated test file `TagHelperDescriptor.TypeName`s to have namespaces to make them easier to read.
#580
- If a `TagHelper` attribute is an `enum` then you no longer need to provide the `enum` name. To override this functionality you can add the `@` symbol.
- Added code generation tests.
- Added `TagHelperDescriptorFactoryTest`s that double for Precompilation tests.
#196
- The init method allows multiple `TagHelper`s to inject data into the `context.Items` bag to properly function when running in unison with other `TagHelper`s that need to communicate with children.
- Transition `GetChildContentAsync` from `TagHelperContext` to `TagHelperOutput`.
- Move `TagHelperContext.GetChildContentAsync` tests to `TagHelperOutputTest`.
- Added `Init` test to ensure `TagHelperRunner` calls it in the correct order.
#571
- Changed non-user facing type names to `Microsoft.AspNet.Razor.TagHelpers`.
- Updated folder structure to reflect new namespaces.
- Updated generated code files to reflect new runtime type namespaces.
#578
- `TagHelper`s used to not flatten correctly resulting in inconsistent start locations for `SyntaxTreeNode`s following/within `TagHelper`s.
- This change indirectly corrected bad indentation that existed in generated C#.
- Added a test to validate `TreesAreDifferent` returns expected behavior when modifying content inside of `TagHelper`.
- Added `TagHelperBlock` `Flatten` test.
#553
- This enables debugging and proper error reporting for dynamic attributes. Without the pragmas errors would showcase generated Razor C# instead of their corresponding .cshtml files.
- Did not have to do any `TagHelper` specific changes since they utilize the same core attribute rendering logic.
- Updated generated C# files for tests.
#569
N. Taylor Mullen
Ryan Nowak
Doug Bunting
Pranav K
Pavel Krymets
Cesar Blum Silveira
Chris R