private RazorPageResult LocatePageFromViewLocations(
ActionContext context,
string pageName,
bool isPartial)
{
// Initialize the dictionary for the typical case of having controller and action tokens.
var areaName = GetNormalizedRouteValue(context, AreaKey);
// Only use the area view location formats if we have an area token.
var viewLocations = !string.IsNullOrEmpty(areaName) ? AreaViewLocationFormats :
ViewLocationFormats;
var expanderContext = new ViewLocationExpanderContext(context, pageName, isPartial);
if (_viewLocationExpanders.Count > 0)
{
expanderContext.Values = new Dictionary <string, string>(StringComparer.Ordinal);
// 1. Populate values from viewLocationExpanders.
// Perf: Avoid allocations
for (var i = 0; i < _viewLocationExpanders.Count; i++)
{
_viewLocationExpanders[i].PopulateValues(expanderContext);
}
}
// 2. With the values that we've accumumlated so far, check if we have a cached result.
IEnumerable <string> locationsToSearch = null;
var cachedResult = _viewLocationCache.Get(expanderContext);
if (!cachedResult.Equals(ViewLocationCacheResult.None))
{
if (cachedResult.IsFoundResult)
{
var page = _pageFactory.CreateInstance(cachedResult.ViewLocation);
if (page != null)
{
// 2a We have a cache entry where a view was previously found.
return(new RazorPageResult(pageName, page));
}
}
else
{
locationsToSearch = cachedResult.SearchedLocations;
}
}
if (locationsToSearch == null)
{
// 2b. We did not find a cached location or did not find a IRazorPage at the cached location.
// The cached value has expired and we need to look up the page.
foreach (var expander in _viewLocationExpanders)
{
viewLocations = expander.ExpandViewLocations(expanderContext, viewLocations);
}
var controllerName = GetNormalizedRouteValue(context, ControllerKey);
locationsToSearch = viewLocations.Select(
location => string.Format(
CultureInfo.InvariantCulture,
location,
pageName,
controllerName,
areaName
));
}
// 3. Use the expanded locations to look up a page.
var searchedLocations = new List <string>();
foreach (var path in locationsToSearch)
{
var page = _pageFactory.CreateInstance(path);
if (page != null)
{
// 3a. We found a page. Cache the set of values that produced it and return a found result.
_viewLocationCache.Set(expanderContext, new ViewLocationCacheResult(path, searchedLocations));
return(new RazorPageResult(pageName, page));
}
searchedLocations.Add(path);
}
// 3b. We did not find a page for any of the paths.
_viewLocationCache.Set(expanderContext, new ViewLocationCacheResult(searchedLocations));
return(new RazorPageResult(pageName, searchedLocations));
}
private ViewEngineResult LocateViewFromViewLocations(ActionContext context,
string viewName,
bool partial)
{
// Initialize the dictionary for the typical case of having controller and action tokens.
var routeValues = context.RouteData.Values;
var areaName = routeValues.GetValueOrDefault <string>(AreaKey);
// Only use the area view location formats if we have an area token.
var viewLocations = !string.IsNullOrEmpty(areaName) ? AreaViewLocationFormats :
ViewLocationFormats;
var expanderContext = new ViewLocationExpanderContext(context, viewName);
if (_viewLocationExpanders.Count > 0)
{
expanderContext.Values = new Dictionary <string, string>(StringComparer.Ordinal);
// 1. Populate values from viewLocationExpanders.
foreach (var expander in _viewLocationExpanders)
{
expander.PopulateValues(expanderContext);
}
}
// 2. With the values that we've accumumlated so far, check if we have a cached result.
var viewLocation = _viewLocationCache.Get(expanderContext);
if (!string.IsNullOrEmpty(viewLocation))
{
var page = _pageFactory.CreateInstance(viewLocation);
if (page != null)
{
// 2a. We found a IRazorPage at the cached location.
return(CreateFoundResult(context, page, viewName, partial));
}
}
// 2b. We did not find a cached location or did not find a IRazorPage at the cached location.
// The cached value has expired and we need to look up the page.
foreach (var expander in _viewLocationExpanders)
{
viewLocations = expander.ExpandViewLocations(expanderContext, viewLocations);
}
// 3. Use the expanded locations to look up a page.
var controllerName = routeValues.GetValueOrDefault <string>(ControllerKey);
var searchedLocations = new List <string>();
foreach (var path in viewLocations)
{
var transformedPath = string.Format(CultureInfo.InvariantCulture,
path,
viewName,
controllerName,
areaName);
var page = _pageFactory.CreateInstance(transformedPath);
if (page != null)
{
// 3a. We found a page. Cache the set of values that produced it and return a found result.
_viewLocationCache.Set(expanderContext, transformedPath);
return(CreateFoundResult(context, page, transformedPath, partial));
}
searchedLocations.Add(transformedPath);
}
// 3b. We did not find a page for any of the paths.
return(ViewEngineResult.NotFound(viewName, searchedLocations));
}
