private void RegisterAlias(string aliasNs, string aliasProp, string actualNs, string actualProp,
                                   AliasOptions aliasForm)
        {
            ParameterAsserts.AssertSchemaNs(aliasNs);
            ParameterAsserts.AssertPropName(aliasProp);
            ParameterAsserts.AssertSchemaNs(actualNs);
            ParameterAsserts.AssertPropName(actualProp);

            // Fix the alias options
            AliasOptions aliasOpts = aliasForm != null
                                         ? new AliasOptions(
                XmpNodeUtils.VerifySetOptions(aliasForm.ToPropertyOptions(), null).
                Options)
                                         : new AliasOptions();

            if (_regex.IsMatch(aliasProp) || _regex.IsMatch(actualProp))
            {
                throw new XmpException("Alias and actual property names must be simple", XmpError.BADXPATH);
            }

            // check if both namespaces are registered
            string aliasPrefix  = GetNamespacePrefix(aliasNs);
            string actualPrefix = GetNamespacePrefix(actualNs);

            if (aliasPrefix == null)
            {
                throw new XmpException("Alias namespace is not registered", XmpError.BADSCHEMA);
            }
            if (actualPrefix == null)
            {
                throw new XmpException("Actual namespace is not registered", XmpError.BADSCHEMA);
            }

            string key = aliasPrefix + aliasProp;

            // check if alias is already existing
            if (_aliasMap.Contains(key))
            {
                throw new XmpException("Alias is already existing", XmpError.BADPARAM);
            }
            if (_aliasMap.Contains(actualPrefix + actualProp))
            {
                throw new XmpException("Actual property is already an alias, use the base property",
                                       XmpError.BADPARAM);
            }

            IXmpAliasInfo aliasInfo = new XmpAliasInfoImpl(actualNs, actualPrefix, actualProp, aliasOpts);

            _aliasMap[key] = aliasInfo;
        }
        private void RegisterAlias(string aliasNs, string aliasProp, string actualNs, string actualProp,
                                   AliasOptions aliasForm) {
            ParameterAsserts.AssertSchemaNs(aliasNs);
            ParameterAsserts.AssertPropName(aliasProp);
            ParameterAsserts.AssertSchemaNs(actualNs);
            ParameterAsserts.AssertPropName(actualProp);

            // Fix the alias options
            AliasOptions aliasOpts = aliasForm != null
                                         ? new AliasOptions(
                                               XmpNodeUtils.VerifySetOptions(aliasForm.ToPropertyOptions(), null).
                                                   Options)
                                         : new AliasOptions();
            if (_regex.IsMatch(aliasProp) || _regex.IsMatch(actualProp)) {
                throw new XmpException("Alias and actual property names must be simple", XmpError.BADXPATH);
            }

            // check if both namespaces are registered
            string aliasPrefix = GetNamespacePrefix(aliasNs);
            string actualPrefix = GetNamespacePrefix(actualNs);
            if (aliasPrefix == null) {
                throw new XmpException("Alias namespace is not registered", XmpError.BADSCHEMA);
            }
            if (actualPrefix == null) {
                throw new XmpException("Actual namespace is not registered", XmpError.BADSCHEMA);
            }

            string key = aliasPrefix + aliasProp;

            // check if alias is already existing
            if (_aliasMap.Contains(key)) {
                throw new XmpException("Alias is already existing", XmpError.BADPARAM);
            }
            if (_aliasMap.Contains(actualPrefix + actualProp)) {
                throw new XmpException("Actual property is already an alias, use the base property",
                                       XmpError.BADPARAM);
            }

            IXmpAliasInfo aliasInfo = new XmpAliasInfoImpl(actualNs, actualPrefix, actualProp, aliasOpts);

            _aliasMap[key] = aliasInfo;
        }