Defining the XML Tree

Defining the XML Tree

• XML documents must contain a root element. This element is "the parent" of all other elements
• The elements in an XML document form a document tree
• The tree starts at the root and branches to the lowest level of the tree
• All elements can have sub elements (child elements):

<root>

<child>

<subchild> ……. </subchild>

</child>

</root>

• The terms parent, child and sibling are used to describe the relationships between elements. Parent elements have children. Children on the same level are called siblings (brothers or sisters)
• All elements can have text content and attributes (just like in HTML)

Book Store XML Example
<bookstore>

<book category="CHILDREN">

<title lang="en">Harry Potter </title>

<author>J K. Rowling</author>

<year>2006</year>

<price>49.65</price>

 </book>

<book category="WEB">

<title lang="en">WT</title>

<author>chris bates</author>

<year>2005</year>

<price>30.00</price>

</book>

 </bookstore>

• The root element in the example is <bookstore>
• All <book> elements in the document are contained within <bookstore>
• The <book> element has 4 children: <title>, < author>, <year>, <price>