Read and write XML in pure Julia.
This package offers fast data structures for reading and writing XML files with a consistent interface:
nodetype(node) → XML.NodeType (an enum type)
tag(node) → String or Nothing
attributes(node) → OrderedDict{String, String} or Nothing
value(node) → String or Nothing
children(node) → Vector{typeof(node)}
is_simple(node) → Bool (whether node is simple .e.g. <tag>item</tag>)
simple_value(node) → e.g. "item" from <tag>item</tag>)
depth(node) → Int
next(node) → typeof(node)
prev(node) → typeof(node)
parent(node) → typeof(node)
using XML
filename = joinpath(dirname(pathof(XML)), "..", "test", "data", "books.xml")
doc = read(filename, Node)
children(doc)
# 2-Element Vector{Node}:
# Node Declaration <?xml version="1.0"?>
# Node Element <catalog> (12 children)
doc[end] # The root node
# Node Element <catalog> (12 children)
doc[end][2] # Second child of root
# Node Element <book id="bk102"> (6 children)- Each item in an XML DOM is classified by its
NodeType. - Every
XML.jlstruct defines anodetype(x)method that returns itsNodeType.
| NodeType | XML Representation | Node Constructor |
|---|---|---|
Document |
An entire document | Document(children...) |
DTD |
<!DOCTYPE ...> |
DTD(...) |
Declaration |
<?xml attributes... ?> |
Declaration(; attrs...) |
ProcessingInstruction |
<?tag attributes... ?> |
ProcessingInstruction(tag; attrs...) |
Comment |
<!-- text --> |
Comment(text) |
CData |
<![CData[text]]> |
CData(text) |
Element |
<tag attributes... > children... </NAME> |
Element(tag, children...; attrs...) |
Text |
the text part of <tag>text</tag> |
Text(text) |
read-ing aNodeloads the entire XML DOM in memory.- See the table above for convenience constructors.
Nodes have some additional methods that aid in construction/mutation:
# Add a child:
push!(parent::Node, child::Node)
# Replace a child:
parent[2] = child
# Add/change an attribute:
node["key"] = value
node["key"]Nodeis an immutable type. However, you can easily create a copy with one or more field values changed by using theNode(::Node; kw...)constructor wherekware the fields you want to change. For example:
node = XML.Element("tag", XML.Text("child"))
simple_value(node)
# "child"
node2 = Node(node, children=XML.Text("changed"))
simple_value(node2)
# "changed"Similar to Cobweb.jl, XML.h enables you to write elements with a simpler syntax:
using XML: h
julia> node = h.parent(
h.child("first child content", id="id1"),
h.child("second child content", id="id2")
)
# Node Element <parent> (2 children)
julia> print(XML.write(node))
# <parent>
# <child id="id1">first child content</child>
# <child id="id2">second child content</child>
# </parent>A lazy data structure that just keeps track of the position in the raw data (Vector{UInt8}) to read from.
- You can iterate over a
LazyNodeto "read" through an XML file:
doc = read(filename, LazyNode)
foreach(println, doc)
# LazyNode Declaration <?xml version="1.0"?>
# LazyNode Element <catalog>
# LazyNode Element <book id="bk101">
# LazyNode Element <author>
# LazyNode Text "Gambardella, Matthew"
# LazyNode Element <title>
# ⋮# Reading from file:
read(filename, Node)
read(filename, LazyNode)
# Parsing from string:
parse(Node, str)
parse(LazyNode, str)
XML.write(filename::String, node) # write to file
XML.write(io::IO, node) # write to stream
XML.write(node) # String- XML.jl performs comparatively to EzXML.jl, which wraps the C library libxml2.
- See the
benchmarks/suite.jlfor the code to produce these results. - The following output was generated in a Julia session with the following
versioninfo:
julia> versioninfo()
Julia Version 1.9.4
Commit 8e5136fa297 (2023-11-14 08:46 UTC)
Build Info:
Official https://julialang.org/ release
Platform Info:
OS: macOS (arm64-apple-darwin22.4.0)
CPU: 10 × Apple M1 Pro
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-14.0.6 (ORCJIT, apple-m1)
Threads: 8 on 8 virtual cores
XML.LazyNode 0.009583
XML.Node ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 1071.32
EzXML.readxml ■■■■■■■■■ 284.346
XMLDict.xml_dict ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 1231.47
Write: XML ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 289.638
Write: EzXML ■■■■■■■■■■■■■ 93.4631
LazyNode ■■■■■■■■■ 51.752
EzXML.StreamReader ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 226.271
XML.LazyNode ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 210.482
EzXML.StreamReader ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 276.238
EzXML.readxml ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 263.269
- XML.jl doesn't automatically escape special characters (
<,>,&,", and') for you. However, we provide utility functions for doing the conversions back and forth:XML.escape(::String)andXML.unescape(::String)XML.escape!(::Node)andXML.unescape!(::Node).