fuelprices/vendor/github.com/antchfx/xmlquery/README.md

xmlquery

Overview

xmlquery is an XPath query package for XML document, lets you extract data or evaluate from XML documents by an XPath expression.

Change Logs

2018-12-23

• added XML output will including comment node. #9

2018-12-03

• added support attribute name with namespace prefix and XML output. #6

Installation

$ go get github.com/antchfx/xmlquery

Getting Started

Parse a XML from URL.

doc, err := xmlquery.LoadURL("http://www.example.com/sitemap.xml")

Parse a XML from string.

s := `<?xml version="1.0" encoding="utf-8"?><rss version="2.0"></rss>`
doc, err := xmlquery.Parse(strings.NewReader(s))

Parse a XML from io.Reader.

f, err := os.Open("../books.xml")
doc, err := xmlquery.Parse(f)

Find authors of all books in the bookstore.

list := xmlquery.Find(doc, "//book//author")
// or
list := xmlquery.Find(doc, "//author")

Find the second book.

book := xmlquery.FindOne(doc, "//book[2]")

Find all book elements and only get id attribute self. (New Feature)

list := xmlquery.Find(doc,"//book/@id")

Find all books with id is bk104.

list := xmlquery.Find(doc, "//book[@id='bk104']")

Find all books that price less than 5.

list := xmlquery.Find(doc, "//book[price<5]")

Evaluate the total price of all books.

expr, err := xpath.Compile("sum(//book/price)")
price := expr.Evaluate(xmlquery.CreateXPathNavigator(doc)).(float64)
fmt.Printf("total price: %f\n", price)

Evaluate the number of all books element.

expr, err := xpath.Compile("count(//book)")
price := expr.Evaluate(xmlquery.CreateXPathNavigator(doc)).(float64)

Create XML document.

doc := &xmlquery.Node{
	Type: xmlquery.DeclarationNode,
	Data: "xml",
	Attr: []xml.Attr{
		xml.Attr{Name: xml.Name{Local: "version"}, Value: "1.0"},
	},
}
root := &xmlquery.Node{
	Data: "rss",
	Type: xmlquery.ElementNode,
}
doc.FirstChild = root
channel := &xmlquery.Node{
	Data: "channel",
	Type: xmlquery.ElementNode,
}
root.FirstChild = channel
title := &xmlquery.Node{
	Data: "title",
	Type: xmlquery.ElementNode,
}
title_text := &xmlquery.Node{
	Data: "W3Schools Home Page",
	Type: xmlquery.TextNode,
}
title.FirstChild = title_text
channel.FirstChild = title
fmt.Println(doc.OutputXML(true))
// <?xml version="1.0"?><rss><channel><title>W3Schools Home Page</title></channel></rss>

Quick Tutorial

import (
	"github.com/antchfx/xmlquery"
)

func main(){
	s := `<?xml version="1.0" encoding="UTF-8" ?>
<rss version="2.0">
<channel>
  <title>W3Schools Home Page</title>
  <link>https://www.w3schools.com</link>
  <description>Free web building tutorials</description>
  <item>
    <title>RSS Tutorial</title>
    <link>https://www.w3schools.com/xml/xml_rss.asp</link>
    <description>New RSS tutorial on W3Schools</description>
  </item>
  <item>
    <title>XML Tutorial</title>
    <link>https://www.w3schools.com/xml</link>
    <description>New XML tutorial on W3Schools</description>
  </item>
</channel>
</rss>`

	doc, err := xmlquery.Parse(strings.NewReader(s))
	if err != nil {
		panic(err)
	}
	channel := xmlquery.FindOne(doc, "//channel")
	if n := channel.SelectElement("title"); n != nil {
		fmt.Printf("title: %s\n", n.InnerText())
	}
	if n := channel.SelectElement("link"); n != nil {
		fmt.Printf("link: %s\n", n.InnerText())
	}
	for i, n := range xmlquery.Find(doc, "//item/title") {
		fmt.Printf("#%d %s\n", i, n.InnerText())
	}
}

List of supported XPath query packages

Name	Description
htmlquery	XPath query package for the HTML document
xmlquery	XPath query package for the XML document
jsonquery	XPath query package for the JSON document

Questions

Please let me know if you have any questions