Folders and files

Name		Name	Last commit message	Last commit date
Latest commit History 205 Commits
.github/workflows		.github/workflows
CONTRIBUTORS		CONTRIBUTORS
LICENSE		LICENSE
README.md		README.md
RELEASE_NOTES.md		RELEASE_NOTES.md
etree.go		etree.go
etree_test.go		etree_test.go
example_test.go		example_test.go
go.mod		go.mod
helpers.go		helpers.go
path.go		path.go
path_test.go		path_test.go

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etree

The etree package is a lightweight, pure go package that expresses XML inthe form of an element tree. Its design was inspired by the PythonElementTreemodule.

Some of the package's capabilities and features:

Represents XML documents as trees of elements for easy traversal.
Imports, serializes, modifies or creates XML documents from scratch.
Writes and reads XML to/from files, byte slices, strings and io interfaces.
Performs simple or complex searches with lightweight XPath-like query APIs.
Auto-indents XML using spaces or tabs for better readability.
Implemented in pure go; depends only on standard go libraries.
Built on top of the goencoding/xmlpackage.

Creating an XML document

The following example creates an XML document from scratch using the etreepackage and outputs its indented contents to stdout.

doc:=etree.NewDocument()doc.CreateProcInst("xml",`version="1.0" encoding="UTF-8"`)doc.CreateProcInst("xml-stylesheet",`type="text/xsl" href="style.xsl"`)people:=doc.CreateElement("People")people.CreateComment("These are all known people")jon:=people.CreateElement("Person")jon.CreateAttr("name","Jon")sally:=people.CreateElement("Person")sally.CreateAttr("name","Sally")doc.Indent(2)doc.WriteTo(os.Stdout)

Output:

<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="style.xsl"?><People><!--These are all known people-->  <Personname="Jon"/>  <Personname="Sally"/></People>

Reading an XML file

Suppose you have a file on disk calledbookstore.xml containing thefollowing data:

<bookstorexmlns:p="urn:schemas-books-com:prices">  <bookcategory="COOKING">    <titlelang="en">Everyday Italian</title>    <author>Giada De Laurentiis</author>    <year>2005</year>    <p:price>30.00</p:price>  </book>  <bookcategory="CHILDREN">    <titlelang="en">Harry Potter</title>    <author>J K. Rowling</author>    <year>2005</year>    <p:price>29.99</p:price>  </book>  <bookcategory="WEB">    <titlelang="en">XQuery Kick Start</title>    <author>James McGovern</author>    <author>Per Bothner</author>    <author>Kurt Cagle</author>    <author>James Linn</author>    <author>Vaidyanathan Nagarajan</author>    <year>2003</year>    <p:price>49.99</p:price>  </book>  <bookcategory="WEB">    <titlelang="en">Learning XML</title>    <author>Erik T. Ray</author>    <year>2003</year>    <p:price>39.95</p:price>  </book></bookstore>

This code reads the file's contents into an etree document.

doc:=etree.NewDocument()iferr:=doc.ReadFromFile("bookstore.xml");err!=nil {panic(err)}

You can also read XML from a string, a byte slice, or anio.Reader.

Processing elements and attributes

This example illustrates several ways to access elements and attributes usingetree selection queries.

root:=doc.SelectElement("bookstore")fmt.Println("ROOT element:",root.Tag)for_,book:=rangeroot.SelectElements("book") {fmt.Println("CHILD element:",book.Tag)iftitle:=book.SelectElement("title");title!=nil {lang:=title.SelectAttrValue("lang","unknown")fmt.Printf("  TITLE: %s (%s)\n",title.Text(),lang)    }for_,attr:=rangebook.Attr {fmt.Printf("  ATTR: %s=%s\n",attr.Key,attr.Value)    }}

Output:

ROOT element: bookstoreCHILD element: book  TITLE: Everyday Italian (en)  ATTR: category=COOKINGCHILD element: book  TITLE: Harry Potter (en)  ATTR: category=CHILDRENCHILD element: book  TITLE: XQuery Kick Start (en)  ATTR: category=WEBCHILD element: book  TITLE: Learning XML (en)  ATTR: category=WEB

Path queries

This example uses etree's path functions to select all book titles that fallinto the category of 'WEB'. The double-slash prefix in the path causes thesearch for book elements to occur recursively; book elements may appear at anylevel of the XML hierarchy.

for_,t:=rangedoc.FindElements("//book[@category='WEB']/title") {fmt.Println("Title:",t.Text())}

Output:

Title: XQuery Kick StartTitle: Learning XML

This example finds the first book element under the root bookstore element andoutputs the tag and text of each of its child elements.

for_,e:=rangedoc.FindElements("./bookstore/book[1]/*") {fmt.Printf("%s: %s\n",e.Tag,e.Text())}

Output:

title: Everyday Italianauthor: Giada De Laurentiisyear: 2005price: 30.00

This example finds all books with a price of 49.99 and outputs their titles.

path:=etree.MustCompilePath("./bookstore/book[p:price='49.99']/title")for_,e:=rangedoc.FindElementsPath(path) {fmt.Println(e.Text())}

Output:

XQuery Kick Start

Note that this example uses the FindElementsPath function, which takes as anargument a pre-compiled path object. Use precompiled paths when you plan tosearch with the same path more than once.