Additional support for XML -- ability to use Elixir Structs

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1

I’ve been doing some work to try to make processing XML documents a
little easier and more intuitive. I’ve built the ability to transform
the xmerl records produced by SweetXml into Elixir Structs.

One benefit of doing this is that you can use dot-notation and (in
IEx) tab completion to reference sub-components of various objects.
For example, if you have an XML element in a variable element1,
then you can use the following to reference its name (tag) and
children:

element1.name
element1.content

I’ve also implemented a small set of helper functions.

See the README for more info.

If you’d like to try it, you can find it here:
https://github.com/dkuhlman/xmlelixirstructs

You can include it in your mix project by adding the following
dependency to your mix.exs:

{:xmlelixirstructs, github: "dkuhlman/xmlelixirstructs"},

If you try it and have comments or suggestions, I’d like to hear
them.

Dave

2 Likes
2

When reading this I expected something different …

It would be nice if you could provide a API which looks like:

xml = """
xml code goes here …
"""

MyLib.parse(xml, "some selector", mapper_module, nested: true)

mapper_module should be a module which implements specific behaviour which let’s say implements such set of functions: struct_mapper/1, content_mapper/2 and cast_func/3.

struct_mapper should be a function which determines module name based on tag, for example:

defmodule Example do
  def struct_mapper("tag-name"), do: ModuleName
end

content_mapper should be a function which determines where specific tag should be added to struct

defmodule Example do
  def content_mapper(MyModule, "content-tag"), do: :content
end

cast_func should be a function like changeset function used in ecto-based projects, for example:

defmodule Example do
  def cast_func(struct, attributes_map, content_map) do
    params = Map.merge(attributes_map, content_map)
    struct |> struct.__struct__.changeset(params) |> do_cast_func()
  end

  defp do_cast_func(%{valid: true} = changeset) do
    {:ok, Changeset.apply_changes(changeset)
  end

  defp do_cast_func(changeset), do: {:error, changeset}
end

Those examples instead of generic predefined structs would allow to nicely cast any XML data into current application structs which would simplify business logic much.

Please notice that with slight changes to mapper_module (I provided just a simple example) you should be able to write a default mapper_module to match your actual predefined structs. That solution would be easier for smaller scripts which does not defines ecto schemas or similar stuff.

What do you think about it?