December 22, 2017
Note to the reader: These commands are current as of Phoenix 1.3.
I’ve been working on a side project to hone my skills in another language and web framework. I’ve decided to pick Elixir and Phoenix. The project I’m working on is named “Dank Kombucha”. Although it’s not quite in a working state, I’ve gone through quite a few learning experiences since the start. There’s nothing quite like a project to really put your theoretical knowledge of something to the test.
Here’s what I’ve learned about Elixir tasks thus far.
Put simply, mix tasks are Elixir functions that offer behavior to complete a built-in or user defined task which can be run from the command line. Tasks are often associated with modules provided by hex dependencies but there are also some built in tasks offered by Elixir.
Here’s an example of a task that is offered by Phoenix to create a new Phoenix project.
mix phx.new my_project
If you want to learn what tasks are available in your project you can run
mix help from within an Elixir project. This will create a list of all possible tasks that can be run from within the Elixir project that you’re working in.
mix help with
grep can help you to cut down on the noise if you already know what you’re looking for.
mix help | grep 'phoenix\|phx' mix local.phoenix # Updates Phoenix locally mix local.phx # Updates the Phoenix project generator locally mix phoenix.gen.html # Generates controller, model and views for an HTML based resource mix phoenix.new # Creates a new Phoenix v1.3.0 application mix phoenix.server # Starts applications and their servers mix phx.digest # Digests and compresses static files mix phx.digest.clean # Removes old versions of static assets. mix phx.gen.channel # Generates a Phoenix channel mix phx.gen.context # Generates a context with functions around an Ecto schema mix phx.gen.embedded # Generates an embedded Ecto schema file mix phx.gen.html # Generates controller, views, and context for an HTML resource mix phx.gen.json # Generates controller, views, and context for a JSON resource mix phx.gen.presence # Generates a Presence tracker mix phx.gen.schema # Generates an Ecto schema and migration file mix phx.gen.secret # Generates a secret mix phx.new # Creates a new Phoenix v1.3.0 application mix phx.new.ecto # Creates a new Ecto project within an umbrella project mix phx.new.web # Creates a new Phoenix web project within an umbrella project mix phx.routes # Prints all routes mix phx.server # Starts applications and their servers
You can also list all tasks under a dependency’s module by executing commands of the following form
mix <dependency_name>. So for example if you want to list tasks that are provided by Ecto you can run the following.
mix ecto ==> comeonin Compiling 2 files (.ex) Generated comeonin app ==> db_connection Compiling 23 files (.ex) Generated db_connection app ==> phoenix_pubsub Compiling 12 files (.ex) Generated phoenix_pubsub app ==> mime Compiling 1 file (.ex) warning: String.strip/1 is deprecated, use String.trim/1 lib/mime.ex:28 Generated mime app ==> plug Compiling 1 file (.erl) Compiling 44 files (.ex) Generated plug app ==> phauxth Compiling 14 files (.ex) Generated phauxth app ==> bamboo Compiling 21 files (.ex) Generated bamboo app ==> phoenix Compiling 74 files (.ex) Generated phoenix app ==> postgrex Compiling 62 files (.ex) Generated postgrex app ==> dank_kombucha_api Ecto v2.2.7 A database wrapper and language integrated query for Elixir. Available tasks: mix ecto.create # Creates the repository storage mix ecto.drop # Drops the repository storage mix ecto.dump # Dumps the repository database structure mix ecto.gen.migration # Generates a new migration for the repo mix ecto.gen.repo # Generates a new repository mix ecto.load # Loads previously dumped database structure mix ecto.migrate # Runs the repository migrations mix ecto.migrations # Displays the repository migration status mix ecto.rollback # Rolls back the repository migrations
For some reason there are some tasks that are not listed when those options are run. I found them by reading through this authN/Z example.
# create the database, run migrations and seed data mix ecto.setup # drop the database and then run ecto.setup mix ecto.reset
The above commands are super useful, specifically the
ecto.reset task. For example if I want to test user authentication of my personal email address, and I want to start tabula rasa, just running
mix ecto.reset allows me to start from ground zero.
# see what routes are defined mix phx.routes
Of course for Phoenix, you can always check the
router.ex file for a list of routes, but sometimes it’s nice to get a pretty printed listing instead.
- David Whitlock, Getting Started
Written by Blake Dietz who lives and works in Boise, ID and loves tinkering in his spare time. Follow him on twitter