Class TreeBase<T>

Base class for tree classes. The tree can be loaded/saved as XML.

public abstract class TreeBase<T> where T : TreeBase<T>

Type Parameters

Name	Description
T

Remarks

Implemented in the same way as System.Xml.Linq.XContainer.

Examples

Shows how to declare a TreeBase-derived class, load tree of nodes from an XML file, find descendant nodes, save the tree to an XML file.

using System.Xml;

class MyTree : TreeBase<MyTree> {
	public string Name { get; set; }
	public int Id { get; private set; }
	public bool IsFolder { get; private set; }

	public MyTree(string name, int id, bool isFolder) { Name = name; Id = id; IsFolder = isFolder; }

	//XML element -> MyTree object
	MyTree(XmlReader x, MyTree parent)
	{
		if(parent == null) { //the root XML element
			if(x.Name != "example") throw new ArgumentException("XML root element must be 'example'");
			IsFolder = true;
		} else {
			switch(x.Name) {
			case "e": break;
			case "f": IsFolder = true; break;
			default: throw new ArgumentException("XML element must be 'e' or 'f'");
			}
#if true //two ways of reading attributes
			Name = x["name"];
			Id = x["id"].ToInt();
#else
			while(x.MoveToNextAttribute()) {
				var v = x.Value;
				switch(x.Name) {
				case "name": Name = v; break;
				case "id": Id = v.ToInt(); break;
				}
			}
#endif
			if(Name.NE()) throw new ArgumentException("no 'name' attribute in XML");
			if(Id == 0) throw new ArgumentException("no 'id' attribute in XML");
		}
	}

	public static MyTree Load(string file) => XmlLoad(file, (x, p) => new MyTree(x, p));

	public void Save(string file) => XmlSave(file, (x, n) => n._XmlWrite(x));

	//MyTree object -> XML element
	void _XmlWrite(XmlWriter x)
	{
		if(Parent == null) {
			x.WriteStartElement("example");
		} else {
			x.WriteStartElement(IsFolder ? "f" : "e");
			x.WriteAttributeString("name", Name);
			x.WriteAttributeString("id", Id.ToString());
		}
	}

	public override string ToString() => $"{new string(' ', Level)}{(IsFolder ? 'f' : 'e')} {Name} ({Id})";
}

static void TNodeExample() {
	/*
	<example>
	  <e name="one" id="1" />
	  <f name="two" id="112">
		<e name="three" id="113" />
		<e name="four" id="114" />
		<f name="five" id="120">
		  <e name="six" id="121" />
		  <e name="seven" id="122" />
		</f>
	  </f>
	  <f name="eight" id="217" />
	  <e name="ten" id="144" />
	</example>
	*/

	var x = MyTree.Load(@"C:\test\example.xml");
	foreach(MyTree n in x.Descendants(true)) print.it(n);
	//print.it(x.Descendants().FirstOrDefault(k => k.Name == "seven")); //find a descendant
	//print.it(x.Descendants().Where(k => k.Level > 2)); //find some descendants
	x.Save(@"C:\test\example2.xml");
}

---

Namespace: Au.Types

Assembly: Au.dll

Inheritance

object

TreeBase<T>

FileTree

Properties

Name	Description
Count	Gets number of direct child nodes.
FirstChild	Gets the first child node, or null if none.
HasChildren	Returns true if this node has child nodes.
HasParent	Returns true if TreeBase<T>.Parent is not null.
Index	Returns 0-based index of this node in parent. Returns -1 if no parent.
LastChild	Gets the last child node, or null if none.
Level	Gets the number of ancestors (parent, its parent and so on).
Next	Gets next sibling node, or null if none.
Parent	Returns the parent node. Can be null.
Previous	Gets previous sibling node, or null if none.
RootAncestor	Returns the root ancestor node. Its TreeBase<T>.Parent is null. Returns this node if its Parent is null.

Methods

Name	Description
AddChild(T, bool)	Adds node n to this node as a child.
AddSibling(T, bool)	Inserts node n before or after this node as a sibling.
Ancestors(bool, bool)	Gets ancestor nodes. The order is from this node towards the root node.
AncestorsFromRoot(bool, bool)	Gets ancestor nodes. The order is from the root node towards this node.
Children(bool)	Gets all direct child nodes.
Descendants(bool, Func<T, bool>)	Gets all descendant nodes (direct children, their children and so on).
IsAncestorOf(T)	Returns true if this node is an ancestor of node n.
IsDescendantOf(Func<T, bool>)	Returns true if this node is a descendant of nearest ancestor node for which predicate returns true.
IsDescendantOf(T)	Returns true if this node is a descendant of node n.
Remove()	Removes this node from its parent.
XmlLoad(string, XmlNodeReader)	Loads XML file and creates tree of nodes from it.
XmlLoad(XmlReader, XmlNodeReader)	Reads XML and creates tree of nodes.
XmlSave(string, XmlNodeWriter, XmlWriterSettings, IEnumerable<T>)	Saves tree of nodes (this and descendants) to an XML file.
XmlSave(XmlWriter, XmlNodeWriter, IEnumerable<T>)	Writes tree of nodes (this and descendants) to an System.Xml.XmlWriter.