XML Builder

Overview

An Elixir library for building XML. It is inspired by the late Jim Weirich's awesome builder library for Ruby.

Each XML node is structured as a tuple of name, attributes map, and content/list.

{name, attrs, content | list}

Installation

Add dependency to your project's mix.exs:

def deps do
  [{:xml_builder, "~> 2.1"}]
end

Examples

A simple element

Like <person id="12345">Josh</person>, would look like:

{:person, %{id: 12345}, "Josh"} |> XmlBuilder.generate

An element with child elements

Like <person id="12345"><first>Josh</first><last>Nussbaum</last></person>.

{:person, %{id: 12345}, [{:first, nil, "Josh"}, {:last, nil, "Nussbaum"}]} |> XmlBuilder.generate

Convenience Functions

For more readability, you can use XmlBuilder's methods instead of creating tuples manually.

XmlBuilder.document(:person, "Josh") |> XmlBuilder.generate

Outputs:

<?xml version="1.0" encoding="UTF-8" ?>
<person>Josh</person>

Building up an element

An element can be built using multiple calls to the element function.

import XmlBuilder

def person(id, first, last) do
  element(:person, %{id: id}, [
    element(:first, first),
    element(:last, last)
  ])
end

iex> [person(123, "Steve", "Jobs"),
      person(456, "Steve", "Wozniak")] |> generate

Outputs.

<person id="123">
  <first>Steve</first>
  <last>Jobs</last>
</person>
<person id="456">
  <first>Steve</first>
  <last>Wozniak</last>
</person>

Using keyed lists

The previous example can be simplified using a keyed list.

import XmlBuilder

def person(id, first, last) do
  element(:person, %{id: id}, first: first,
                              last: last)
end

iex> person(123, "Josh", "Nussbaum") |> generate(format: :none)
"<person id=\"123\"><first>Josh</first><last>Nussbaum</last></person>"

DOCTYPE declarations

A DOCTYPE can be declared by applying the doctype function at the first position of a list of elements in a document definition:

import XmlBuilder

document([
  doctype("html", public: ["-//W3C//DTD XHTML 1.0 Transitional//EN",
                "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"]),
  element(:html, "Hello, world!")
]) |> generate

Outputs.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>Hello, world!</html>

Encoding

While the output is always UTF-8 and has to be converted in another place, you can override the encoding statement in the XML declaration with the encoding option.

import XmlBuilder

document(:oldschool)
|> generate(encoding: "ISO-8859-1")
|> :unicode.characters_to_binary(:unicode, :latin1)

Outputs.

<?xml version="1.0" encoding="ISO-8859-1"?>
<oldschool/>

Standalone

Should you need standalone="yes" in the XML declaration, you can pass standalone: true as option to the generate/2 call.

import XmlBuilder

document(:outsider)
|> generate(standalone: true)

Outputs.

<?xml version="1.0" standalone="yes"?>
<outsider/>

Formatting

To remove indentation, pass format: :none option to XmlBuilder.generate/2.

doc |> XmlBuilder.generate(format: :none)

The default is to formatting with indentation, which is equivalent to XmlBuilder.generate(doc, format: :indent).

devstopfix/xml_builder

XML Builder

Overview

Installation

Examples

A simple element

An element with child elements

Convenience Functions

Building up an element

Using keyed lists

DOCTYPE declarations

Encoding

Standalone

Formatting

License