C# XmlNode.SelectSingleElement方法代码示例

        internal static XmlNode ProcessSageLinkElement(SageContext context, XmlNode node)
        {
            Contract.Requires<ArgumentNullException>(node != null);
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            XmlElement linkElem = (XmlElement) node;
            string linkName = context.ProcessText(linkElem.GetAttribute("ref"));
            bool rawString = linkElem.GetAttribute("raw").EqualsAnyOf("1", "yes", "true");

            if (!string.IsNullOrEmpty(linkName) && rawString)
            {
                if (context.Url.Links.ContainsKey(linkName))
                {
                    linkElem.InnerText = context.Url.Links[linkName].Value;
                }

                return linkElem;
            }

            string linkHref = context.Url.GetUrl(linkElem);
            if (!string.IsNullOrEmpty(linkHref))
            {
                linkElem.SetAttribute("href", linkHref);
            }

            foreach (XmlNode child in node.ChildNodes)
            {
                XmlNode processed = NodeEvaluator.GetNodeHandler(child)(context, child);
                if (processed != null)
                    node.ReplaceChild(processed, child);
                else
                    node.RemoveChild(child);
            }

            return linkElem;
        }

        internal static XmlNode ProcessSageUrlElement(SageContext context, XmlNode node)
        {
            Contract.Requires<ArgumentNullException>(node != null);
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            string linkHref = context.Url.GetUrl((XmlElement) node);

            if (!string.IsNullOrEmpty(linkHref))
            {
                if (node.NodeType == XmlNodeType.Element)
                    return node.OwnerDocument.CreateTextNode(linkHref);
            }

            return node;
        }

        internal static XmlNode ProcessHrefAttribute(SageContext context, XmlNode node)
        {
            Contract.Requires<ArgumentNullException>(node != null);
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            node.InnerText = context.ProcessText(node.InnerText);
            return node;
        }

        internal static XmlNode ProcessSageBaseHrefElement(SageContext context, XmlNode node)
        {
            Contract.Requires<ArgumentNullException>(node != null);
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            XmlElement result = node.OwnerDocument.CreateElement("base", XmlNamespaces.XHtmlNamespace);
            result.SetAttribute("href", context.BaseHref);

            return result;
        }

        internal static XmlNode ProcessContextSwitchNode(SageContext context, XmlNode switchNode)
        {
            if (switchNode.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return switchNode;

            XmlElement switchElem = (XmlElement) switchNode;

            string propName = switchElem.GetAttribute("property");
            string key = switchElem.GetAttribute("key");

            if (string.IsNullOrEmpty(propName))
            {
                log.ErrorFormat("The switch node in document '{0}' is missing the required property attribute",
                    switchNode.OwnerDocument.BaseURI);

                return switchNode;
            }

            string propValue = SageContext.GetContextProperty(context, propName, key);

            int caseNum = 0;
            bool caseFound = false;
            XmlDocumentFragment result = switchNode.OwnerDocument.CreateDocumentFragment();

            foreach (XmlElement caseNode in switchNode.SelectNodes("context:case", XmlNamespaces.Manager))
            {
                string testValue = caseNode.GetAttribute("test");
                if (string.IsNullOrEmpty(testValue))
                {
                    log.WarnFormat(
                        "The case node with index {0} of switch node '{1}' in document '{2}' didn't specify a test condition.",
                            caseNum, propName, switchNode.OwnerDocument.BaseURI);

                    continue;
                }

                if (testValue.Equals(propValue, StringComparison.InvariantCultureIgnoreCase))
                {
                    foreach (XmlNode node in caseNode.SelectNodes("node()"))
                        result.AppendChild(context.ProcessNode(node));

                    caseFound = true;
                    break;
                }

                caseNum += 1;
            }

            if (!caseFound)
            {
                XmlNode defaultNode = switchNode.SelectSingleNode("context:default", XmlNamespaces.Manager);
                if (defaultNode != null)
                {
                    foreach (XmlNode node in defaultNode.SelectNodes("node()"))
                        result.AppendChild(context.ProcessNode(node));
                }
            }

            return result;
        }

        internal static XmlNode ProcessContextIfNode(SageContext context, XmlNode node)
        {
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            XmlElement element = (XmlElement) node;
            XmlDocumentFragment result = node.OwnerDocument.CreateDocumentFragment();

            string expression = element.GetAttribute("expression");
            string propName = element.GetAttribute("property");
            string key = element.GetAttribute("key");
            string equals = element.GetAttribute("equals");
            string notEquals = element.GetAttribute("not-equals");
            bool nodeValid = false;

            if (!string.IsNullOrWhiteSpace(expression))
            {
                var text = context.textEvaluator.Process(expression);
                nodeValid = !string.IsNullOrWhiteSpace(text);
            }
            else
            {
                string propValue = SageContext.GetContextProperty(context, propName, key);
                if (notEquals != string.Empty)
                    nodeValid = !propValue.Equals(notEquals, StringComparison.InvariantCultureIgnoreCase);
                else if (equals != string.Empty)
                    nodeValid = propValue.Equals(equals, StringComparison.InvariantCultureIgnoreCase);
            }

            if (!nodeValid)
                return null;

            foreach (XmlNode child in node.SelectNodes("node()"))
                result.AppendChild(context.ProcessNode(child));

            return result;
        }

        internal static XmlNode ProcessBaseHrefNode(SageContext context, XmlNode node)
        {
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            XmlElement result = node.OwnerDocument.CreateElement("base", XmlNamespaces.XHtmlNamespace);
            result.SetAttribute("href", context.BaseHref);
            return result;
        }

        internal static XmlNode ProcessSageVersionNode(SageContext context, XmlNode node)
        {
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            string version = Assembly.GetExecutingAssembly().GetName().Version.ToString();
            return node.OwnerDocument.CreateTextNode(version);
        }

        internal static XmlNode ProcessContextValueNode(SageContext context, XmlNode node)
        {
            if (node.SelectSingleElement("ancestor::sage:literal", XmlNamespaces.Manager) != null)
                return node;

            XmlElement valueElem = (XmlElement) node;

            string xpath = valueElem.GetAttribute("xpath");
            if (!string.IsNullOrWhiteSpace(xpath))
            {
                XmlNode value = node.SelectSingleNode(xpath, XmlNamespaces.Manager);
                node.OwnerDocument.CreateTextNode(value.InnerText);
            }

            string propName = valueElem.GetAttribute("property");

            if (string.IsNullOrWhiteSpace(propName))
                return node.OwnerDocument.CreateTextNode(context.textEvaluator.Process(valueElem.InnerText));

            string propKey = valueElem.GetAttribute("key");
            string propValue = SageContext.GetContextProperty(context, propName, propKey);

            if (propValue != null)
                return node.OwnerDocument.CreateTextNode(propValue);

            // default: return node as is
            return node;
        }