On HtmlHelper<T> we now support contextualizing an instance of
HtmlHelper<TBase> with a ViewDataDictionary<TDerived> in
ViewContext.ViewData.
This can happen in some situations when the model for a RazorPage has
been changed using a page application model convention.
In these cases we just build a new ViewDataDictionary<TBase> and pass in
the TDerived model as an instance.
- #6662
- users can now provide a `name` or `data-valmsg-for` attribute to avoid `ArgumentException`s
- affects `<input>`, `<select>`, `<textarea>` elements and validation message `<div>`s
- remove `fullName` check in `DefaultHtmlGenerator.GetCurrentValues(...)` entirely
The new workaround is _not_ identical to changing `ViewData.TemplateInfo.HtmlFieldPrefix`
- does not change where expression values are found in `ModelState` or `ViewData`
- likely needs to be combined with additional workarounds i.e. for advanced use only
nits:
- clean up some excessive argument naming; add a few missing argument names
- take VS suggestions in changed classes e.g. inline a few variable declarations
- clean up some test data
- #3918
- lazy-load `TagBuilder.InnerHtml`; add `HasInnerHtml` property for conservative use
- depends on aspnet/HtmlAbstractions@0781b5a (adds `HtmlContentBuilder.Count`)
- don't use a `HtmlContentBuilder` at all in `DefaultHtmlGenerator.GenerateValidationSummary()`
- avoid instantiating `HtmlContentBuilder` when short-circuits make it unnecessary
- provide correct `HtmlContentBuilder` capacity where known
- #3918
- precompute size of `StringBuilder` in `ExpressionHelper`
- reduce `string` allocations in `ViewDataEvaluator`
- also get rid of `Enumeration` state machines
- reduce the size of a few objects; use more expression-valued properties
- e.g. don't store `_modelType` in `ModelExplorer`
- add `EmptyArray<TElement>`; make empty arrays consistently `static`
- avoid `string.Split()` in HTML and tag helpers
nits:
- make `ExpressionHelperTest` tests more stringent
- correct `Message` for an `ArgumentNullException`
- remove excess `using`s in classes I touched (but often ended up leaving otherwise unchanged)
- improve doc comments
- remove `ToString()` call on a `string`
- avoid encoding `string.Empty`
- fix test file name
- remove useless variables
- correct spelling
- improve whitespace
- #5028
- helpers similar to our HTML or tag helpers can use the new singleton to examine or add validation attributes
- in the most common case, helpers add validation attributes to a `TagBuilder`
- separate `DefaultValidationHtmlAttributeProvider` from `DefaultHtmlGenerator`
- avoids creating two instances of the `DefaultHtmlGenerator` singleton
- would be even uglier to require callers to cast an `IHtmlGenerator` to `ValidationHtmlAttributeProvider`
- `[Obsolete]` old `DefaultHtmlGenerator` constructor
- #5209
- update affected `HtmlHelperValiationSummaryTest` and functional tests
- add `ValidationSummaryTagHelperTest` tests to cover related scenarios
##### Behaviour changes when no errors exist for the model:
###### Tag helper
``` html
<div asp-validation-summary="ModelOnly" class="order"><h3>Oopsie<h3></div>
```
previously generated
``` html
<div class="order validation-summary-errors"><h3>Oopsie</h3><ul><li style="display:none"></li>
</ul></div>
```
and now generates
``` html
<div class="order"><h3>Oopsie</h3></div>
```
###### HTML helper
``` c#
@Html.ValidationSummary(excludePropertyErrors: true, message: "Oopsie")
```
previously generated
``` html
<div class=\"validation-summary-errors\"><span>Oopsie</span>
<ul><li style=\"display:none\"></li>
</ul></div>
```
and now generates nothing (`@HtmlString.Empty`).
- #4116
- generalize rules for `ModelMetadata` creation; minimize metadata changes when Model is updated
- down to a single special case in VDD for `Nullable<T>`
- note existing functional tests did not need to change
- remove `ViewDataDictionary(ViewDataDictionary, object)` constructor; use `new VDD<object>(source, model)`
- allow all `Model` assignments in a view component
- copy-constructed VDD in `ViewComponentContext` previously preserved the source's declared type
nits:
- do not call `virtual SetModel()` method from constructor; now mostly redundant
- logic in copy constructor and `SetModel()` is consistent but different enough to keep code separate
- add some missing doc comments
- fix doc comment property versus type confusion; never need to specify `ViewDataDictionary.` prefix
- fix a few `TemplateBuilder` comments and remove unnecessary `model: null` argument to VDD constructor
- Simplify things that used to rely on HtmlTextWriter. This behavior is
now the default.
- Simplify a whole mess of Razor TextWriter code.
- Integration test for merging of TagHelper buffers back into the 'main'
buffer.