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namespace System.Web.Routing {
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
internal sealed class ParsedRoute {
public ParsedRoute(IList<PathSegment> pathSegments) {
Debug.Assert(pathSegments != null);
PathSegments = pathSegments;
}
private IList<PathSegment> PathSegments {
get;
set;
}
public BoundUrl Bind(RouteValueDictionary currentValues, RouteValueDictionary values, RouteValueDictionary defaultValues, RouteValueDictionary constraints) {
if (currentValues == null) {
currentValues = new RouteValueDictionary();
}
if (values == null) {
values = new RouteValueDictionary();
}
if (defaultValues == null) {
defaultValues = new RouteValueDictionary();
}
// The set of values we should be using when generating the URL in this route
RouteValueDictionary acceptedValues = new RouteValueDictionary();
// Keep track of which new values have been used
HashSet<string> unusedNewValues = new HashSet<string>(values.Keys, StringComparer.OrdinalIgnoreCase);
// Step 1: Get the list of values we're going to try to use to match and generate this URL
// Find out which entries in the URL are valid for the URL we want to generate.
// If the URL had ordered parameters a="1", b="2", c="3" and the new values
// specified that b="9", then we need to invalidate everything after it. The new
// values should then be a="1", b="9", c=<no value>.
ForEachParameter(PathSegments, delegate(ParameterSubsegment parameterSubsegment) {
// If it's a parameter subsegment, examine the current value to see if it matches the new value
string parameterName = parameterSubsegment.ParameterName;
object newParameterValue;
bool hasNewParameterValue = values.TryGetValue(parameterName, out newParameterValue);
if (hasNewParameterValue) {
unusedNewValues.Remove(parameterName);
}
object currentParameterValue;
bool hasCurrentParameterValue = currentValues.TryGetValue(parameterName, out currentParameterValue);
if (hasNewParameterValue && hasCurrentParameterValue) {
if (!RoutePartsEqual(currentParameterValue, newParameterValue)) {
// Stop copying current values when we find one that doesn't match
return false;
}
}
// If the parameter is a match, add it to the list of values we will use for URL generation
if (hasNewParameterValue) {
if (IsRoutePartNonEmpty(newParameterValue)) {
acceptedValues.Add(parameterName, newParameterValue);
}
}
else {
if (hasCurrentParameterValue) {
acceptedValues.Add(parameterName, currentParameterValue);
}
}
return true;
});
// Add all remaining new values to the list of values we will use for URL generation
foreach (var newValue in values) {
if (IsRoutePartNonEmpty(newValue.Value)) {
if (!acceptedValues.ContainsKey(newValue.Key)) {
acceptedValues.Add(newValue.Key, newValue.Value);
}
}
}
// Add all current values that aren't in the URL at all
foreach (var currentValue in currentValues) {
string parameterName = currentValue.Key;
if (!acceptedValues.ContainsKey(parameterName)) {
ParameterSubsegment parameterSubsegment = GetParameterSubsegment(PathSegments, parameterName);
if (parameterSubsegment == null) {
acceptedValues.Add(parameterName, currentValue.Value);
}
}
}
// Add all remaining default values from the route to the list of values we will use for URL generation
ForEachParameter(PathSegments, delegate(ParameterSubsegment parameterSubsegment) {
if (!acceptedValues.ContainsKey(parameterSubsegment.ParameterName)) {
object defaultValue;
if (!IsParameterRequired(parameterSubsegment, defaultValues, out defaultValue)) {
// Add the default value only if there isn't already a new value for it and
// only if it actually has a default value, which we determine based on whether
// the parameter value is required.
acceptedValues.Add(parameterSubsegment.ParameterName, defaultValue);
}
}
return true;
});
// All required parameters in this URL must have values from somewhere (i.e. the accepted values)
bool hasAllRequiredValues = ForEachParameter(PathSegments, delegate(ParameterSubsegment parameterSubsegment) {
object defaultValue;
if (IsParameterRequired(parameterSubsegment, defaultValues, out defaultValue)) {
if (!acceptedValues.ContainsKey(parameterSubsegment.ParameterName)) {
// If the route parameter value is required that means there's
// no default value, so if there wasn't a new value for it
// either, this route won't match.
return false;
}
}
return true;
});
if (!hasAllRequiredValues) {
return null;
}
// All other default values must match if they are explicitly defined in the new values
RouteValueDictionary otherDefaultValues = new RouteValueDictionary(defaultValues);
ForEachParameter(PathSegments, delegate(ParameterSubsegment parameterSubsegment) {
otherDefaultValues.Remove(parameterSubsegment.ParameterName);
return true;
});
foreach (var defaultValue in otherDefaultValues) {
object value;
if (values.TryGetValue(defaultValue.Key, out value)) {
unusedNewValues.Remove(defaultValue.Key);
if (!RoutePartsEqual(value, defaultValue.Value)) {
// If there is a non-parameterized value in the route and there is a
// new value for it and it doesn't match, this route won't match.
return null;
}
}
}
// Step 2: If the route is a match generate the appropriate URL
StringBuilder url = new StringBuilder();
StringBuilder pendingParts = new StringBuilder();
bool pendingPartsAreAllSafe = false;
bool blockAllUrlAppends = false;
for (int i = 0; i < PathSegments.Count; i++) {
PathSegment pathSegment = PathSegments[i]; // parsedRouteUrlPart
if (pathSegment is SeparatorPathSegment) {
if (pendingPartsAreAllSafe) {
// Accept
if (pendingParts.Length > 0) {
if (blockAllUrlAppends) {
return null;
}
// Append any pending literals to the URL
url.Append(pendingParts.ToString());
pendingParts.Length = 0;
}
}
pendingPartsAreAllSafe = false;
// Guard against appending multiple separators for empty segements
if (pendingParts.Length > 0 && pendingParts[pendingParts.Length - 1] == '/') {
// Dev10 676725: Route should not be matched if that causes mismatched tokens
// Dev11 86819: We will allow empty matches if all subsequent segments are null
if (blockAllUrlAppends) {
return null;
}
// Append any pending literals to the URL(without the trailing slash) and prevent any future appends
url.Append(pendingParts.ToString(0, pendingParts.Length - 1));
pendingParts.Length = 0;
blockAllUrlAppends = true;
}
else {
pendingParts.Append("/");
}
}
else {
ContentPathSegment contentPathSegment = pathSegment as ContentPathSegment;
if (contentPathSegment != null) {
// Segments are treated as all-or-none. We should never output a partial segment.
// If we add any subsegment of this segment to the generated URL, we have to add
// the complete match. For example, if the subsegment is "{p1}-{p2}.xml" and we
// used a value for {p1}, we have to output the entire segment up to the next "/".
// Otherwise we could end up with the partial segment "v1" instead of the entire
// segment "v1-v2.xml".
bool addedAnySubsegments = false;
foreach (PathSubsegment subsegment in contentPathSegment.Subsegments) {
LiteralSubsegment literalSubsegment = subsegment as LiteralSubsegment;
if (literalSubsegment != null) {
// If it's a literal we hold on to it until we are sure we need to add it
pendingPartsAreAllSafe = true;
pendingParts.Append(UrlEncode(literalSubsegment.Literal));
}
else {
ParameterSubsegment parameterSubsegment = subsegment as ParameterSubsegment;
if (parameterSubsegment != null) {
if (pendingPartsAreAllSafe) {
// Accept
if (pendingParts.Length > 0) {
if (blockAllUrlAppends) {
return null;
}
// Append any pending literals to the URL
url.Append(pendingParts.ToString());
pendingParts.Length = 0;
addedAnySubsegments = true;
}
}
pendingPartsAreAllSafe = false;
// If it's a parameter, get its value
object acceptedParameterValue;
bool hasAcceptedParameterValue = acceptedValues.TryGetValue(parameterSubsegment.ParameterName, out acceptedParameterValue);
if (hasAcceptedParameterValue) {
unusedNewValues.Remove(parameterSubsegment.ParameterName);
}
object defaultParameterValue;
defaultValues.TryGetValue(parameterSubsegment.ParameterName, out defaultParameterValue);
if (RoutePartsEqual(acceptedParameterValue, defaultParameterValue)) {
// If the accepted value is the same as the default value, mark it as pending since
// we won't necessarily add it to the URL we generate.
pendingParts.Append(UrlEncode(Convert.ToString(acceptedParameterValue, CultureInfo.InvariantCulture)));
}
else {
if (blockAllUrlAppends) {
return null;
}
// Add the new part to the URL as well as any pending parts
if (pendingParts.Length > 0) {
// Append any pending literals to the URL
url.Append(pendingParts.ToString());
pendingParts.Length = 0;
}
url.Append(UrlEncode(Convert.ToString(acceptedParameterValue, CultureInfo.InvariantCulture)));
addedAnySubsegments = true;
}
}
else {
Debug.Fail("Invalid path subsegment type");
}
}
}
if (addedAnySubsegments) {
// See comment above about why we add the pending parts
if (pendingParts.Length > 0) {
if (blockAllUrlAppends) {
return null;
}
// Append any pending literals to the URL
url.Append(pendingParts.ToString());
pendingParts.Length = 0;
}
}
}
else {
Debug.Fail("Invalid path segment type");
}
}
}
if (pendingPartsAreAllSafe) {
// Accept
if (pendingParts.Length > 0) {
if (blockAllUrlAppends) {
return null;
}
// Append any pending literals to the URL
url.Append(pendingParts.ToString());
}
}
// Process constraints keys
if (constraints != null) {
// If there are any constraints, mark all the keys as being used so that we don't
// generate query string items for custom constraints that don't appear as parameters
// in the URL format.
foreach (var constraintsItem in constraints) {
unusedNewValues.Remove(constraintsItem.Key);
}
}
// Add remaining new values as query string parameters to the URL
if (unusedNewValues.Count > 0) {
// Generate the query string
bool firstParam = true;
foreach (string unusedNewValue in unusedNewValues) {
object value;
if (acceptedValues.TryGetValue(unusedNewValue, out value)) {
url.Append(firstParam ? '?' : '&');
firstParam = false;
url.Append(Uri.EscapeDataString(unusedNewValue));
url.Append('=');
url.Append(Uri.EscapeDataString(Convert.ToString(value, CultureInfo.InvariantCulture)));
}
}
}
return new BoundUrl {
Url = url.ToString(),
Values = acceptedValues
};
}
private static string EscapeReservedCharacters(Match m) {
return "%" + Convert.ToUInt16(m.Value[0]).ToString("x2", CultureInfo.InvariantCulture);
}
private static bool ForEachParameter(IList<PathSegment> pathSegments, Func<ParameterSubsegment, bool> action) {
for (int i = 0; i < pathSegments.Count; i++) {
PathSegment pathSegment = pathSegments[i];
if (pathSegment is SeparatorPathSegment) {
// We only care about parameter subsegments, so skip this
continue;
}
else {
ContentPathSegment contentPathSegment = pathSegment as ContentPathSegment;
if (contentPathSegment != null) {
foreach (PathSubsegment subsegment in contentPathSegment.Subsegments) {
LiteralSubsegment literalSubsegment = subsegment as LiteralSubsegment;
if (literalSubsegment != null) {
// We only care about parameter subsegments, so skip this
continue;
}
else {
ParameterSubsegment parameterSubsegment = subsegment as ParameterSubsegment;
if (parameterSubsegment != null) {
if (!action(parameterSubsegment)) {
return false;
}
}
else {
Debug.Fail("Invalid path subsegment type");
}
}
}
}
else {
Debug.Fail("Invalid path segment type");
}
}
}
return true;
}
private static ParameterSubsegment GetParameterSubsegment(IList<PathSegment> pathSegments, string parameterName) {
ParameterSubsegment foundParameterSubsegment = null;
bool continueProcessing = ForEachParameter(pathSegments, delegate(ParameterSubsegment parameterSubsegment) {
if (String.Equals(parameterName, parameterSubsegment.ParameterName, StringComparison.OrdinalIgnoreCase)) {
foundParameterSubsegment = parameterSubsegment;
return false;
}
else {
return true;
}
});
return foundParameterSubsegment;
}
private static bool IsParameterRequired(ParameterSubsegment parameterSubsegment, RouteValueDictionary defaultValues, out object defaultValue) {
if (parameterSubsegment.IsCatchAll) {
defaultValue = null;
return false;
}
return !defaultValues.TryGetValue(parameterSubsegment.ParameterName, out defaultValue);
}
private static bool IsRoutePartNonEmpty(object routePart) {
string routePartString = routePart as string;
if (routePartString != null) {
return (routePartString.Length > 0);
}
return (routePart != null);
}
public RouteValueDictionary Match(string virtualPath, RouteValueDictionary defaultValues) {
IList<string> requestPathSegments = RouteParser.SplitUrlToPathSegmentStrings(virtualPath);
if (defaultValues == null) {
defaultValues = new RouteValueDictionary();
}
RouteValueDictionary matchedValues = new RouteValueDictionary();
// This flag gets set once all the data in the URL has been parsed through, but
// the route we're trying to match against still has more parts. At this point
// we'll only continue matching separator characters and parameters that have
// default values.
bool ranOutOfStuffToParse = false;
// This value gets set once we start processing a catchall parameter (if there is one
// at all). Once we set this value we consume all remaining parts of the URL into its
// parameter value.
bool usedCatchAllParameter = false;
for (int i = 0; i < PathSegments.Count; i++) {
PathSegment pathSegment = PathSegments[i];
if (requestPathSegments.Count <= i) {
ranOutOfStuffToParse = true;
}
string requestPathSegment = ranOutOfStuffToParse ? null : requestPathSegments[i];
if (pathSegment is SeparatorPathSegment) {
if (ranOutOfStuffToParse) {
// If we're trying to match a separator in the route but there's no more content, that's OK
}
else {
if (!String.Equals(requestPathSegment, "/", StringComparison.Ordinal)) {
return null;
}
}
}
else {
ContentPathSegment contentPathSegment = pathSegment as ContentPathSegment;
if (contentPathSegment != null) {
if (contentPathSegment.IsCatchAll) {
Debug.Assert(i == (PathSegments.Count - 1), "If we're processing a catch-all, we should be on the last route segment.");
MatchCatchAll(contentPathSegment, requestPathSegments.Skip(i), defaultValues, matchedValues);
usedCatchAllParameter = true;
}
else {
if (!MatchContentPathSegment(contentPathSegment, requestPathSegment, defaultValues, matchedValues)) {
return null;
}
}
}
else {
Debug.Fail("Invalid path segment type");
}
}
}
if (!usedCatchAllParameter) {
if (PathSegments.Count < requestPathSegments.Count) {
// If we've already gone through all the parts defined in the route but the URL
// still contains more content, check that the remaining content is all separators.
for (int i = PathSegments.Count; i < requestPathSegments.Count; i++) {
if (!RouteParser.IsSeparator(requestPathSegments[i])) {
return null;
}
}
}
}
// Copy all remaining default values to the route data
if (defaultValues != null) {
foreach (var defaultValue in defaultValues) {
if (!matchedValues.ContainsKey(defaultValue.Key)) {
matchedValues.Add(defaultValue.Key, defaultValue.Value);
}
}
}
return matchedValues;
}
private void MatchCatchAll(ContentPathSegment contentPathSegment, IEnumerable<string> remainingRequestSegments, RouteValueDictionary defaultValues, RouteValueDictionary matchedValues) {
string remainingRequest = String.Join(String.Empty, remainingRequestSegments.ToArray());
ParameterSubsegment catchAllSegment = contentPathSegment.Subsegments[0] as ParameterSubsegment;
object catchAllValue;
if (remainingRequest.Length > 0) {
catchAllValue = remainingRequest;
}
else {
defaultValues.TryGetValue(catchAllSegment.ParameterName, out catchAllValue);
}
matchedValues.Add(catchAllSegment.ParameterName, catchAllValue);
}
private bool MatchContentPathSegment(ContentPathSegment routeSegment, string requestPathSegment, RouteValueDictionary defaultValues, RouteValueDictionary matchedValues) {
if (String.IsNullOrEmpty(requestPathSegment)) {
// If there's no data to parse, we must have exactly one parameter segment and no other segments - otherwise no match
if (routeSegment.Subsegments.Count > 1) {
return false;
}
ParameterSubsegment parameterSubsegment = routeSegment.Subsegments[0] as ParameterSubsegment;
if (parameterSubsegment == null) {
return false;
}
// We must have a default value since there's no value in the request URL
object parameterValue;
if (defaultValues.TryGetValue(parameterSubsegment.ParameterName, out parameterValue)) {
// If there's a default value for this parameter, use that default value
matchedValues.Add(parameterSubsegment.ParameterName, parameterValue);
return true;
}
else {
// If there's no default value, this segment doesn't match
return false;
}
}
// Find last literal segment and get its last index in the string
int lastIndex = requestPathSegment.Length;
int indexOfLastSegmentUsed = routeSegment.Subsegments.Count - 1;
ParameterSubsegment parameterNeedsValue = null; // Keeps track of a parameter segment that is pending a value
LiteralSubsegment lastLiteral = null; // Keeps track of the left-most literal we've encountered
while (indexOfLastSegmentUsed >= 0) {
int newLastIndex = lastIndex;
ParameterSubsegment parameterSubsegment = routeSegment.Subsegments[indexOfLastSegmentUsed] as ParameterSubsegment;
if (parameterSubsegment != null) {
// Hold on to the parameter so that we can fill it in when we locate the next literal
parameterNeedsValue = parameterSubsegment;
}
else {
LiteralSubsegment literalSubsegment = routeSegment.Subsegments[indexOfLastSegmentUsed] as LiteralSubsegment;
if (literalSubsegment != null) {
lastLiteral = literalSubsegment;
int startIndex = lastIndex - 1;
// If we have a pending parameter subsegment, we must leave at least one character for that
if (parameterNeedsValue != null) {
startIndex--;
}
if (startIndex < 0) {
return false;
}
int indexOfLiteral = requestPathSegment.LastIndexOf(literalSubsegment.Literal, startIndex, StringComparison.OrdinalIgnoreCase);
if (indexOfLiteral == -1) {
// If we couldn't find this literal index, this segment cannot match
return false;
}
// If the first subsegment is a literal, it must match at the right-most extent of the request URL.
// Without this check if your route had "/Foo/" we'd match the request URL "/somethingFoo/".
// This check is related to the check we do at the very end of this function.
if (indexOfLastSegmentUsed == (routeSegment.Subsegments.Count - 1)) {
if ((indexOfLiteral + literalSubsegment.Literal.Length) != requestPathSegment.Length) {
return false;
}
}
newLastIndex = indexOfLiteral;
}
else {
Debug.Fail("Invalid path segment type");
}
}
if ((parameterNeedsValue != null) && (((lastLiteral != null) && (parameterSubsegment == null)) || (indexOfLastSegmentUsed == 0))) {
// If we have a pending parameter that needs a value, grab that value
int parameterStartIndex;
int parameterTextLength;
if (lastLiteral == null) {
if (indexOfLastSegmentUsed == 0) {
parameterStartIndex = 0;
}
else {
parameterStartIndex = newLastIndex;
Debug.Fail("indexOfLastSegementUsed should always be 0 from the check above");
}
parameterTextLength = lastIndex;
}
else {
// If we're getting a value for a parameter that is somewhere in the middle of the segment
if ((indexOfLastSegmentUsed == 0) && (parameterSubsegment != null)) {
parameterStartIndex = 0;
parameterTextLength = lastIndex;
}
else {
parameterStartIndex = newLastIndex + lastLiteral.Literal.Length;
parameterTextLength = lastIndex - parameterStartIndex;
}
}
string parameterValueString = requestPathSegment.Substring(parameterStartIndex, parameterTextLength);
if (String.IsNullOrEmpty(parameterValueString)) {
// If we're here that means we have a segment that contains multiple sub-segments.
// For these segments all parameters must have non-empty values. If the parameter
// has an empty value it's not a match.
return false;
}
else {
// If there's a value in the segment for this parameter, use the subsegment value
matchedValues.Add(parameterNeedsValue.ParameterName, parameterValueString);
}
parameterNeedsValue = null;
lastLiteral = null;
}
lastIndex = newLastIndex;
indexOfLastSegmentUsed--;
}
// If the last subsegment is a parameter, it's OK that we didn't parse all the way to the left extent of
// the string since the parameter will have consumed all the remaining text anyway. If the last subsegment
// is a literal then we *must* have consumed the entire text in that literal. Otherwise we end up matching
// the route "Foo" to the request URL "somethingFoo". Thus we have to check that we parsed the *entire*
// request URL in order for it to be a match.
// This check is related to the check we do earlier in this function for LiteralSubsegments.
return (lastIndex == 0) || (routeSegment.Subsegments[0] is ParameterSubsegment);
}
private static bool RoutePartsEqual(object a, object b) {
string sa = a as string;
string sb = b as string;
if (sa != null && sb != null) {
// For strings do a case-insensitive comparison
return String.Equals(sa, sb, StringComparison.OrdinalIgnoreCase);
}
else {
if (a != null && b != null) {
// Explicitly call .Equals() in case it is overridden in the type
return a.Equals(b);
}
else {
// At least one of them is null. Return true if they both are
return a == b;
}
}
}
// Dev10 601636 Work around Uri.EscapeUriString not encoding #,&
private static string UrlEncode(string str) {
string escape = Uri.EscapeUriString(str);
return Regex.Replace(escape, "([#;?:@&=+$,])", new MatchEvaluator(EscapeReservedCharacters));
}
}
}
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