private void UpdatePathSegments(
int i,
ActionDescriptor action,
IDictionary <string, string> resolvedRequiredValues,
RoutePattern routePattern,
List <RoutePatternPathSegment> newPathSegments,
ref IDictionary <string, IList <IParameterPolicy> > allParameterPolicies)
{
List <RoutePatternPart> segmentParts = null; // Initialize only as needed
var segment = newPathSegments[i];
for (var j = 0; j < segment.Parts.Count; j++)
{
var part = segment.Parts[j];
if (part is RoutePatternParameterPart parameterPart)
{
if (resolvedRequiredValues.TryGetValue(parameterPart.Name, out var parameterRouteValue))
{
if (segmentParts == null)
{
segmentParts = segment.Parts.ToList();
}
if (allParameterPolicies == null)
{
allParameterPolicies = MvcEndpointInfo.BuildParameterPolicies(routePattern.Parameters, _parameterPolicyFactory);
}
// Route value could be null if it is a "known" route value.
// Do not use the null value to de-normalize the route pattern,
// instead leave the parameter unchanged.
// e.g.
// RouteValues will contain a null "page" value if there are Razor pages
// Skip replacing the {page} parameter
if (parameterRouteValue != null)
{
if (allParameterPolicies.TryGetValue(parameterPart.Name, out var parameterPolicies))
{
// Check if the parameter has a transformer policy
// Use the first transformer policy
for (var k = 0; k < parameterPolicies.Count; k++)
{
if (parameterPolicies[k] is IOutboundParameterTransformer parameterTransformer)
{
parameterRouteValue = parameterTransformer.TransformOutbound(parameterRouteValue);
break;
}
}
}
segmentParts[j] = RoutePatternFactory.LiteralPart(parameterRouteValue);
}
}
}
}
// A parameter part was replaced so replace segment with updated parts
if (segmentParts != null)
{
newPathSegments[i] = RoutePatternFactory.Segment(segmentParts);
}
}
// CreateEndpoints processes the route pattern, replacing area/controller/action parameters with endpoint values
// Because of default values it is possible for a route pattern to resolve to multiple endpoints
private int CreateEndpoints(
List <Endpoint> endpoints,
ref StringBuilder patternStringBuilder,
ActionDescriptor action,
int routeOrder,
RoutePattern routePattern,
IReadOnlyDictionary <string, object> allDefaults,
IReadOnlyDictionary <string, object> nonInlineDefaults,
string name,
RouteValueDictionary dataTokens,
IDictionary <string, IList <IParameterPolicy> > allParameterPolicies,
bool suppressLinkGeneration,
bool suppressPathMatching)
{
var newPathSegments = routePattern.PathSegments.ToList();
for (var i = 0; i < newPathSegments.Count; i++)
{
// Check if the pattern can be shortened because the remaining parameters are optional
//
// e.g. Matching pattern {controller=Home}/{action=Index}/{id?} against HomeController.Index
// can resolve to the following endpoints:
// - /Home/Index/{id?}
// - /Home
// - /
if (UseDefaultValuePlusRemainingSegmentsOptional(i, action, allDefaults, newPathSegments))
{
var subPathSegments = newPathSegments.Take(i);
var subEndpoint = CreateEndpoint(
action,
name,
GetPattern(ref patternStringBuilder, subPathSegments),
subPathSegments,
nonInlineDefaults,
routeOrder++,
dataTokens,
suppressLinkGeneration,
suppressPathMatching);
endpoints.Add(subEndpoint);
}
List <RoutePatternPart> segmentParts = null; // Initialize only as needed
var segment = newPathSegments[i];
for (var j = 0; j < segment.Parts.Count; j++)
{
var part = segment.Parts[j];
if (part.IsParameter &&
part is RoutePatternParameterPart parameterPart &&
action.RouteValues.ContainsKey(parameterPart.Name))
{
if (segmentParts == null)
{
segmentParts = segment.Parts.ToList();
}
if (allParameterPolicies == null)
{
allParameterPolicies = MvcEndpointInfo.BuildParameterPolicies(routePattern.Parameters, _parameterPolicyFactory);
}
var parameterRouteValue = action.RouteValues[parameterPart.Name];
// Replace parameter with literal value
if (allParameterPolicies.TryGetValue(parameterPart.Name, out var parameterPolicies))
{
// Check if the parameter has a transformer policy
// Use the first transformer policy
for (var k = 0; k < parameterPolicies.Count; k++)
{
if (parameterPolicies[k] is IParameterTransformer parameterTransformer)
{
parameterRouteValue = parameterTransformer.Transform(parameterRouteValue);
break;
}
}
}
segmentParts[j] = RoutePatternFactory.LiteralPart(parameterRouteValue);
}
}
// A parameter part was replaced so replace segment with updated parts
if (segmentParts != null)
{
newPathSegments[i] = RoutePatternFactory.Segment(segmentParts);
}
}
var endpoint = CreateEndpoint(
action,
name,
GetPattern(ref patternStringBuilder, newPathSegments),
newPathSegments,
nonInlineDefaults,
routeOrder++,
dataTokens,
suppressLinkGeneration,
suppressPathMatching);
endpoints.Add(endpoint);
return(routeOrder);
string GetPattern(ref StringBuilder sb, IEnumerable <RoutePatternPathSegment> segments)
{
if (sb == null)
{
sb = new StringBuilder();
}
RoutePatternWriter.WriteString(sb, segments);
var rawPattern = sb.ToString();
sb.Length = 0;
return(rawPattern);
}
}