sodapopcan
Request for feedback on Vials (wrappers for mix tasks)
EDIT: I forgot to link the repo, ha: GitHub - sodapopcan/vials: Tweak your mix generators
This project is not quite ready for prime-time but I wanted to solicit some early feedback to see if it’s something people would want to use.
This started out with the idea of being able to manipulate the output of phx_new but I ended up making it a more general wrapper around mix tasks.
A “vial” is a file that is named after a mix task and saved in ~/vials (this is configurable).
Here is one for mix phx.new:
# ~/vials/phx.new.ex
defmodule SomeModuleName.ItDoesNot.Matter.WhatItsCalled do
use Vials
base_path @target
remove "priv/static/favicon.ico"
remove_comments() # remove comments from all .ex and .exs file.
# remove_comments/1 with accept a filename or list of filenames.
add_dep {:some_dep, "~> 0.0.1"}
if @opts[:binary_id] do
create "lib/#{@target}/schema.ex", """
defmodule #{Macro.camelize(@target)}.Schema do
defmacro __using__(_) do
quote do
use Ecto.Schema, warn: false
@primary_key {:id, :binary_id, autogenerate: true}
@foreign_key_type :binary_id
end
end
end
"""
end
edit "lib/#{@target}/router.ex", fn contents ->
# Crudely manipulate the contents of `router.ex` with Elixir's standard library.
end
end
The next step is to add a few more DSL functions (like move) and then some helper functions for editing files. I’m very new to AST manipulation and have been getting comfortable with Sourceror. This actually works right now:
def SomeMod do
use Vials
create "some_file.ex" do
defmodule Foo do
def bar do
"baz"
end
end
end
end
…though there is no way to use the injected module attributes. I’m getting there!
Anyway, I just wanted some early feedback. I’m also open to another name. I don’t mind Vials but there is already a project on hexpm called Vial (singular), I’m not sure how active it is.
I’m currently in the midst of refactoring so I’m not too open to PRs atm but I would really appreciate feedback and generally what the appetite for something like this is.
There’s more info in the README.
Thanks!
Most Liked
BartOtten
This seems very nice to me. Less burden to keep custom generators up-to-date with upstream and possibly working with different versions of Phoenix.
Pre-mature note: a place to share Vials would be nice 
Nefcairon
So this is to personalize, individualize, adapt, tweak the result of a mix task? "If so, “aftercare” comes to my mind.
There are always certain steps of changes that everyone undertakes after creating a new phoenix app (e.g. change password in config/dev.exs for the db). I would be interested in other people’s vials, too.
sodapopcan
Yeah, I’m really just writing it with generators in mind, though theoretically you could use it to wrap any mix task. I think once I cut a 0.1.0 release I’ll make an new “Introducing” thread and make that clearer as I don’t think “wrappers for mix tasks” is particularly appealing at a glance.
I like that name but I think I’m going to stick with Vials as I like being able to have a name for the files that is related to the name. That would be hard with aftercare.
I was talking about with with @BartOtten. I’m not sure exactly how to handle that yet. I’m a little wary of accepting PRs in the project as it could get out of hand, but if this project gets any real use then there should definitely be a solution for sharing vials. I’m open to suggestions, of course!
D4no0
After reading the comments it surely is a tool with a lot of potential!
The thing that would make it real interesting would be to be able to access the task code before/after it is executed? The only sad thing about this is that the classic mix task is just a run function and it has side effects in it.
Maybe an interesting approach would be to build a data structure at the end of the task and have some kind of “server” execute everything afterwards? this would open possibilities to mix and pipe these kind of tasks.
sodapopcan
That’s interesting. I’m currently just focused on a DSL, well, basically for creating and manipulating source files but I’m open to other use-cases
Can you give an example of what you’re describing? Like metaprogramming a mix task itself?
Otherwise currently Vial files work like you describe in that they just build up a list of messages which get processed by a “Runner”. Currently it uses an Agent to store up the messages but I’m likely going to refactor to use a module attribute—the Agent got me going quicker as I didn’t have to figure out how to store anonymous functions in a module attribute but I think I have a solution. I’m also in the midst of refactoring to clean some stuff up (namely the guys of add_dep shouldn’t be in the DSL module.
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