Documentation
¶
Overview ¶
Package xmlpath implements a strict subset of the XPath specification for the Go language.
The XPath specification is available at:
http://www.w3.org/TR/xpath
Path expressions supported by this package are in the following format, with all components being optional:
/axis-name::node-test[predicate]/axis-name::node-test[predicate]
At the moment, xmlpath is compatible with the XPath specification to the following extent:
- All axes are supported ("child", "following-sibling", etc)
- All abbreviated forms are supported (".", "//", etc)
- All node types except for namespace are supported
- Predicates are restricted to [N], path, and [path=literal] forms
- Only a single predicate is supported per path step
- Richer expressions and namespaces are not supported
For example, assuming the following document:
<library>
<!-- Great book. -->
<book id="b0836217462" available="true">
<isbn>0836217462</isbn>
<title lang="en">Being a Dog Is a Full-Time Job</title>
<quote>I'd dog paddle the deepest ocean.</quote>
<author id="CMS">
<?echo "go rocks"?>
<name>Charles M Schulz</name>
<born>1922-11-26</born>
<dead>2000-02-12</dead>
</author>
<character id="PP">
<name>Peppermint Patty</name>
<born>1966-08-22</born>
<qualification>bold, brash and tomboyish</qualification>
</character>
<character id="Snoopy">
<name>Snoopy</name>
<born>1950-10-04</born>
<qualification>extroverted beagle</qualification>
</character>
</book>
</library>
The following examples are valid path expressions, and the first match has the indicated value:
/library/book/isbn => "0836217462" library/*/isbn => "0836217462" /library/book/../book/./isbn => "0836217462" /library/book/character[2]/name => "Snoopy" /library/book/character[born='1950-10-04']/name => "Snoopy" /library/book//node()[@id='PP']/name => "Peppermint Patty" //book[author/@id='CMS']/title => "Being a Dog Is a Full-Time Job"}, /library/book/preceding::comment() => " Great book. "
To run an expression, compile it, and then apply the compiled path to any number of context nodes, from one or more parsed xml documents:
path := xmlpath.MustCompile("/library/book/isbn")
root, err := xmlpath.Parse(file)
if err != nil {
log.Fatal(err)
}
if value, ok := path.String(root); ok {
fmt.Println("Found:", value)
}
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Iter ¶
type Iter struct {
// contains filtered or unexported fields
}
Iter iterates over node sets.
type Node ¶
type Node struct {
// contains filtered or unexported fields
}
Node is an item in an xml tree that was compiled to be processed via xml paths. A node may represent:
- An element in the xml document (<body>)
- An attribute of an element in the xml document (href="...")
- A comment in the xml document (<!--...-->)
- A processing instruction in the xml document (<?...?>)
- Some text within the xml document
func ParseDecoder ¶
ParseDecoder parses the xml document being decoded by d and returns its root node.
func ParseHTML ¶
ParseHTML reads an HTML-like document from r, parses it, and returns its root node.
func (*Node) Bytes ¶
Bytes returns the string value of node as a byte slice. See Node.String for a description of what the string value of a node is.
func (*Node) String ¶
String returns the string value of node.
The string value of a node is:
- For element nodes, the concatenation of all text nodes within the element.
- For text nodes, the text itself.
- For attribute nodes, the attribute value.
- For comment nodes, the text within the comment delimiters.
- For processing instruction nodes, the content of the instruction.
type Path ¶
type Path struct {
// contains filtered or unexported fields
}
Path is a compiled path that can be applied to a context node to obtain a matching node set. A single Path can be applied concurrently to any number of context nodes.
func MustCompile ¶
MustCompile returns the compiled path, and panics if there are any errors.
func (*Path) Bytes ¶
Bytes returns as a byte slice the string value of the first node matched by p on the given context.
See the documentation of Node.String.
Source Files