예제 #1
0
        public bool BuildUrl(Route route, RequestContext requestContext, RouteValueDictionary userValues, out string value)
        {
            value = null;
            if (requestContext == null)
            {
                return(false);
            }

            RouteData            routeData     = requestContext.RouteData;
            RouteValueDictionary defaultValues = route != null ? route.Defaults : null;
            RouteValueDictionary ambientValues = routeData.Values;

            if (defaultValues != null && defaultValues.Count == 0)
            {
                defaultValues = null;
            }
            if (ambientValues != null && ambientValues.Count == 0)
            {
                ambientValues = null;
            }
            if (userValues != null && userValues.Count == 0)
            {
                userValues = null;
            }

            // Check URL parameters
            // It is allowed to take ambient values for required parameters if:
            //
            //   - there are no default values provided
            //   - the default values dictionary contains at least one required
            //     parameter value
            //
            bool canTakeFromAmbient;

            if (defaultValues == null)
            {
                canTakeFromAmbient = true;
            }
            else
            {
                canTakeFromAmbient = false;
                foreach (KeyValuePair <string, bool> de in parameterNames)
                {
                    if (defaultValues.ContainsKey(de.Key))
                    {
                        canTakeFromAmbient = true;
                        break;
                    }
                }
            }

            bool allMustBeInUserValues = false;

            foreach (KeyValuePair <string, bool> de in parameterNames)
            {
                string parameterName = de.Key;
                // Is the parameter required?
                if (defaultValues == null || !defaultValues.ContainsKey(parameterName))
                {
                    // Yes, it is required (no value in defaults)
                    // Has the user provided value for it?
                    if (userValues == null || !userValues.ContainsKey(parameterName))
                    {
                        if (allMustBeInUserValues)
                        {
                            return(false);                            // partial override => no match
                        }
                        if (!canTakeFromAmbient || ambientValues == null || !ambientValues.ContainsKey(parameterName))
                        {
                            return(false);                            // no value provided => no match
                        }
                    }
                    else if (canTakeFromAmbient)
                    {
                        allMustBeInUserValues = true;
                    }
                }
            }

            // Check for non-url parameters
            if (defaultValues != null)
            {
                foreach (var de in defaultValues)
                {
                    string parameterName = de.Key;

                    if (parameterNames.ContainsKey(parameterName))
                    {
                        continue;
                    }

                    object parameterValue = null;
                    // Has the user specified value for this parameter and, if
                    // yes, is it the same as the one in defaults?
                    if (userValues != null && userValues.TryGetValue(parameterName, out parameterValue))
                    {
                        object defaultValue = de.Value;
                        if (defaultValue is string && parameterValue is string)
                        {
                            if (String.Compare((string)defaultValue, (string)parameterValue, StringComparison.Ordinal) != 0)
                            {
                                return(false);                                // different value => no match
                            }
                        }
                        else if (defaultValue != parameterValue)
                        {
                            return(false);                            // different value => no match
                        }
                    }
                }
            }

            // Check the constraints
            RouteValueDictionary constraints = route != null ? route.Constraints : null;

            if (constraints != null && constraints.Count > 0)
            {
                HttpContextBase context = requestContext.HttpContext;
                bool            invalidConstraint;

                foreach (var de in constraints)
                {
                    if (!Route.ProcessConstraintInternal(context, route, de.Value, de.Key, userValues, RouteDirection.UrlGeneration, out invalidConstraint) ||
                        invalidConstraint)
                    {
                        return(false);                        // constraint not met => no match
                    }
                }
            }

            // We're a match, generate the URL
            var  ret     = new StringBuilder();
            bool canTrim = true;

            // Going in reverse order, so that we can trim without much ado
            int tokensCount = tokens.Length - 1;

            for (int i = tokensCount; i >= 0; i--)
            {
                PatternToken token = tokens [i];
                if (token == null)
                {
                    if (i < tokensCount && ret.Length > 0 && ret [0] != '/')
                    {
                        ret.Insert(0, '/');
                    }
                    continue;
                }

                if (token.Type == PatternTokenType.Literal)
                {
                    ret.Insert(0, token.Name);
                    continue;
                }

                string parameterName = token.Name;
                object tokenValue;

#if SYSTEMCORE_DEP
                if (userValues.GetValue(parameterName, out tokenValue))
                {
                    if (!defaultValues.Has(parameterName, tokenValue))
                    {
                        canTrim = false;
                        if (tokenValue != null)
                        {
                            ret.Insert(0, tokenValue.ToString());
                        }
                        continue;
                    }

                    if (!canTrim && tokenValue != null)
                    {
                        ret.Insert(0, tokenValue.ToString());
                    }
                    continue;
                }

                if (defaultValues.GetValue(parameterName, out tokenValue))
                {
                    object ambientTokenValue;
                    if (ambientValues.GetValue(parameterName, out ambientTokenValue))
                    {
                        tokenValue = ambientTokenValue;
                    }

                    if (!canTrim && tokenValue != null)
                    {
                        ret.Insert(0, tokenValue.ToString());
                    }
                    continue;
                }

                canTrim = false;
                if (ambientValues.GetValue(parameterName, out tokenValue))
                {
                    if (tokenValue != null)
                    {
                        ret.Insert(0, tokenValue.ToString());
                    }
                    continue;
                }
#endif
            }

            // All the values specified in userValues that aren't part of the original
            // URL, the constraints or defaults collections are treated as overflow
            // values - they are appended as query parameters to the URL
            if (userValues != null)
            {
                bool first = true;
                foreach (var de in userValues)
                {
                    string parameterName = de.Key;

#if SYSTEMCORE_DEP
                    if (parameterNames.ContainsKey(parameterName) || defaultValues.Has(parameterName) || constraints.Has(parameterName))
                    {
                        continue;
                    }
#endif

                    object parameterValue = de.Value;
                    if (parameterValue == null)
                    {
                        continue;
                    }

                    var parameterValueAsString = parameterValue as string;
                    if (parameterValueAsString != null && parameterValueAsString.Length == 0)
                    {
                        continue;
                    }

                    if (first)
                    {
                        ret.Append('?');
                        first = false;
                    }
                    else
                    {
                        ret.Append('&');
                    }


                    ret.Append(Uri.EscapeDataString(parameterName));
                    ret.Append('=');
                    if (parameterValue != null)
                    {
                        ret.Append(Uri.EscapeDataString(de.Value.ToString()));
                    }
                }
            }

            value = ret.ToString();
            return(true);
        }