Pdl

Pdl is a rather simple set of tools that enables something similar to the "dataloader" pattern, using Erlang process dictionaries.

In short, you can use it to batch up actions across a process (i.e. a single Phoenix request) and resolve them later (towards the end of the process)

This toolset is relatively minimal, leaving most of the implementation details up to the user.

Installation

This package can be installed by adding pdl to your list of dependencies in mix.exs:

def deps do
  [
    {:pdl, "~> 0.1.1"}
  ]
end

Basic Usage

# Somewhere in your process, where you want to add things to a batch

Pdl.add(:posts, post.id)
# => :ok

# Later, i.e. right before the end of the request

Pdl.run_all(:posts, fn post_ids ->
  Posts.get_many(post_ids)
end)
# => result of `Posts.get_many(post_ids)`

Documentation can be found at https://hexdocs.pm/pdl.