Hi all!

I’m still fairly new to elixir (mostly Ruby/C#/Rust in my background) and this is my first stab at a semi-useful library so feedback would be much appreciated!

I created a declarative library for creating data mappers that consume XML via strings or streams and return well-defined elixir structs, optionally with default values, attribute extraction, text extraction, and type casting. It’s also fairly fast at what it does based on my benchmarks on some large-ish XML documents. If you’ve used SaxMachine with Ruby it’s almost a 1:1 port to see if I could define a similar interface, since I really like the semantics of the SaxMachine DSL. The general gist is that you describe your expected structure and the library extracts out that information for you without having to specify XPaths or write Sax handlers yourself. This library also tries to be compatible with 3 (currently) XML parsers that support SAX-- erlsom, xmerl_sax_parser, and saxy.

Repo: GitHub - ducharmemp/saxaboom
Hex: saxaboom | Hex

Example:

You can turn:

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications
      with XML.</description>
   </book>
</catalog>

Into:

{:ok,
 %Catalog{
   books: [
     %Book{
       id: "bk101",
       author: "Gambardella, Matthew",
       title: "XML Developer's Guide",
       genre: "Computer",
       price: 44.95,
       publish_date: {:ok, ~D[2000-10-01]},
       description: "An in-depth look at creating applications\n      with XML."
     }
   ]
 }}

with the following Saxaboom definition:

defmodule Book do
  use Saxaboom.Mapper

  document do
    element :book, as: :id, value: :id
    element :author
    element :title
    element :genre
    element :price, cast: :float
    element :publish_date, cast: &__MODULE__.parse_date/1
    element :description
  end

  def parse_date(value), do: Date.from_iso8601(value)
end


defmodule Catalog do
  use Saxaboom.Mapper

  document do
    elements :book, as: :books, into: %Book{}
  end
end