Automatisierung Scripting

XPath-Ausdrücke

11.12.2009

Beispiel-XML

<?xml version=“1.0“ encoding=“ISO-8859-1“?>
<bookstore>
<book>
<title lang=“eng“>Harry Potter</title>
<price>29.99</price>
</book>
<book>
<title lang=“eng“>Learning XML</title>
<price>39.95</price>
</book>
</bookstore>

XPath Elemente

| Expression | Bedeutung|
| —- | —- |
| nodename | Selects all child nodes of the named node |
| / | Selects from the root node |
| // | Selects nodes in the document from the current node that match the selection no matter where they are |
| . | Selects the current node |
| .. | Selects the parent of the current node |
| @ | Selects attributes |
| bookstore | Selects all the child nodes of the bookstore element |
| /bookstore | Selects the root element bookstore Note: If the path starts with a slash ( / ) it always represents an absolute path to an element! |
| bookstore/book | Selects all book elements that are children of bookstore |
| //book | Selects all book elements no matter where they are in the document |
| bookstore//book | Selects all book elements that are descendant of the bookstore element, no matter where they are under the bookstore element |
| //@lang | Selects all attributes that are named lang |
| /bookstore/book[1] | Selects the first book element that is the child of the bookstore element. |
| /bookstore/book[last()] | Selects the last book element that is the child of the bookstore element |
| /bookstore/book[last()-1] | Selects the last but one book element that is the child of the bookstore element |
| /bookstore/book[position()<3] | Selects the first two book elements that are children of the bookstore element | | //title[@lang] | Selects all the title elements that have an attribute named lang | | //title[@lang=‘eng‘] | Selects all the title elements that have an attribute named lang with a value of ‚eng‘ | | /bookstore/book[price>35.00] | Selects all the book elements of the bookstore element that have a price element with a value greater than 35.00 |
| /bookstore/book[price>35.00]/title | Selects all the title elements of the book elements of the bookstore element that have a price element with a value greater than 35.00 |
| **Wildcard** | **Description** |
| * | Matches any element node |
| @* | Matches any attribute node |
| node() | Matches any node of any kind |
| /bookstore/* | Selects all the child nodes of the bookstore element |
| //* | Selects all elements in the document |
| //title[@*] | Selects all title elements which have any attribute |
| //book/title | //book/price | Selects all the title AND price elements of all book elements |
| //title | //price | Selects all the title AND price elements in the document |
| /bookstore/book/title | //price | Selects all the title elements of the book element of the bookstore element AND all the price elements in the document |
| **AxisName** | **Result** |
| ancestor | Selects all ancestors (parent, grandparent, etc.) of the current node |
| ancestor-or-self | Selects all ancestors (parent, grandparent, etc.) of the current node and the current node itself |
| attribute | Selects all attributes of the current node |
| child | Selects all children of the current node |
| descendant | Selects all descendants (children, grandchildren, etc.) of the current node |
| descendant-or-self | Selects all descendants (children, grandchildren, etc.) of the current node and the current node itself |
| following | Selects everything in the document after the closing tag of the current node |
| following-sibling | Selects all siblings after the current node |
| namespace | Selects all namespace nodes of the current node |
| parent | Selects the parent of the current node |
| preceding | Selects everything in the document that is before the start tag of the current node |
| preceding-sibling | Selects all siblings before the current node |
| self | Selects the current node |
| **Example** | **Result** |
| child::book | Selects all book nodes that are children of the current node |
| attribute::lang | Selects the lang attribute of the current node |
| child::* | Selects all children of the current node |
| attribute::* | Selects all attributes of the current node |
| child::text() | Selects all text child nodes of the current node |
| child::node() | Selects all child nodes of the current node |
| descendant::book | Selects all book descendants of the current node |
| ancestor::book | Selects all book ancestors of the current node |
| ancestor-or-self::book | Selects all book ancestors of the current node – and the current as well if it is a book node |
| child::*/child::price | Selects all price grandchildren of the current node |

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