Separates the MMP into two phases:
1). Creation of the ModelMetadata, discovery of properties and attributes
(reflection) is part of the MMP
2). Lookup of details based on attributes is now part of another phase,
and has its results cached.
Users can now implements and register an IFooMetadataProvider to customize
a single aspect of metadata (see how data annotations does it).
- #1468
- Always use `ModelExplorer` in `<select/>`, `DropDownListFor()` and `ListBoxFor()` cases
- allows evaluation of more-complex expressions
- Use `ViewData.Model` in `DropDownList()` and `ListBox()` template cases
- `ViewData` was previously ignored in these cases
nit: change `ViewDataDictionary.Eval()` to return `Model` if `expression` is `null` or empty
- now `throw` on `null` or empty `expression` name in `ViewDataEvaluator.Eval()`
- simplifies some of the higher-level code
- no change to `selectList` fallback; `Model` incorrect for that case
- no change to `GenerateRadioButton()`; would change behaviour unrelated to #1468
- this helper uses incorrect `ViewData` lookup text, see #1487
- see commit 9d5364c
- never correct to pass a `Func<object>` to `GetExplorerForExpression()`
- `<label/>` tests succeeded because that tag helper doesn't use expression result
- `<select/>` tests succeeded because that tag helper gets result from `ViewData`
- does not use `ModelExplorer` due to #1468
nit: update variable names `metadata` -> `modelExplorer`
This change provides caching for the results of searching for view
components and discovering their names.
In our ViewComponent perf test, selecting the component type was about 25%
of the execution of MVC (due to uncached reflection). This change brings
that down to about 1%.
This is a small change to remove uncached reflection. There are some other
code paths where use of view components results in a hotspot. Leaving
those issues to be tracked as part of a larger design issue.
- jQuery and jQuery-validation files were not being copied
- update to match more-recent VS templates
nit: simplify wwwroot/lib directory tree slightly