PostgreSQL XML data and Elixir / Ecto?

[christhekeele]

@silverdr

Although even on parsers/builders (especially the latter) choice seems to be limited.

I’m don’t know how expansive the choice needs to be, really—parsing and building are pretty straightforward until you need SAX, and even then you just use a SAX parser if you’re memory constrained. I’ve built a few XML-handling things in Elixir just fine with sweet_xml and xml_builder. Usually end up with something like this as my main entrypoint, with application-specific helpers for common workflows, and submodules for specific domains (ex XML.SOAP).

XML module

defmodule XML do
  defmacro __using__(_options \\ []) do
    quote do
      import XML, only: [sigil_x: 1, sigil_x: 2]
    end
  end

  @type document() :: SweetXml.doc()
  @type element() :: SweetXml.xmlElement()

  ####
  # XML builder functions
  ##

  defdelegate document(elements), to: XmlBuilder
  defdelegate document(name, attrs_or_content), to: XmlBuilder
  defdelegate document(name, attrs, content), to: XmlBuilder

  defdelegate element(name), to: XmlBuilder
  defdelegate element(name, attrs), to: XmlBuilder
  defdelegate element(name, attrs, content), to: XmlBuilder

  ####
  # XML parser functions
  ##
  defdelegate generate(any, options \\ []), to: XmlBuilder
  defdelegate parse(document, options \\ []), to: SweetXml
  defdelegate sigil_x(path, modifiers \\ []), to: SweetXml
  defdelegate xpath(parent, spec, subspec \\ []), to: SweetXml
end

@silverdr

I guess the option is to somehow treat the column as text and then do some string parsing, etc.

That really depends on what you’re doing with the XML. If you’re looking for feedback, share some details about the problem you’re trying to solve with us!