Mix v1.6.6 Mix.Task behaviour View Source
A simple module that provides conveniences for creating, loading and manipulating tasks.
A Mix task can be defined by simply using Mix.Task
in a module starting with Mix.Tasks.
and defining
the run/1
function:
defmodule Mix.Tasks.Echo do
use Mix.Task
def run(args) do
Mix.shell.info Enum.join(args, " ")
end
end
The run/1
function will receive a list of all arguments passed
to the command line.
Attributes
There are a few attributes available in Mix tasks to configure them in Mix:
@shortdoc
- makes the task public with a short description that appears onmix help
@recursive
- runs the task recursively in umbrella projects@preferred_cli_env
- recommends environment to run task. It is used in absence of a Mix project recommendation, or explicitMIX_ENV
, and it only works for tasks in the current project.@preferred_cli_env
is not loaded from dependencies as we need to know the environment before dependencies are loaded.
Documentation
Users can read the documentation for public Mix tasks by running mix help my_task
.
The documentation that will be shown is the @moduledoc
of the task’s module.
Link to this section Summary
Functions
Checks if an alias called task
exists
Returns all loaded task modules
Clears all invoked tasks, allowing them to be reinvoked
Receives a task name and returns the task module if found
Receives a task name and retrieves the task module
Loads all tasks in all code paths
Loads all tasks in the given paths
Gets the moduledoc for the given task module
Gets preferred CLI environment for the task
Checks if the task should be run recursively for all sub-apps in umbrella projects
Reenables a given task so it can be executed again down the stack
Reruns task
with the given arguments
Runs a task
with the given args
Gets the shortdoc for the given task module
Returns true
if given module is a task
Returns the task name for the given module
Callbacks
A task needs to implement run
which receives
a list of command line args
Link to this section Types
Link to this section Functions
Checks if an alias called task
exists.
For more information about task aliasing, take a look at the “Aliasing”
section in the docs for Mix
.
Returns all loaded task modules.
Modules that are not yet loaded won’t show up.
Check load_all/0
if you want to preload all tasks.
Clears all invoked tasks, allowing them to be reinvoked.
This operation is not recursive.
Receives a task name and returns the task module if found.
Otherwise returns nil
in case the module
exists, but it isn’t a task or cannot be found.
Receives a task name and retrieves the task module.
Exceptions
Mix.NoTaskError
- raised if the task could not be foundMix.InvalidTaskError
- raised if the task is not a validMix.Task
Loads all tasks in all code paths.
Loads all tasks in the given paths
.
Gets the moduledoc for the given task module
.
Returns the moduledoc or nil
.
Gets preferred CLI environment for the task.
Returns environment (for example, :test
, or :prod
), or nil
.
Checks if the task should be run recursively for all sub-apps in umbrella projects.
Returns true
or false
.
Reenables a given task so it can be executed again down the stack.
Both alias and the regular stack are reenabled when this function is called.
If an umbrella project reenables a task, it is reenabled for all child projects.
Reruns task
with the given arguments.
This function reruns the given task; to do that, it first re-enables the task and then runs it as normal.
Runs a task
with the given args
.
If the task was not yet invoked, it runs the task and returns the result.
If there is an alias with the same name, the alias will be invoked instead of the original task.
If the task or alias were already invoked, it does not
run them again and simply aborts with :noop
.
It may raise an exception if an alias or a task can’t
be found or the task is invalid. Check get!/1
for more
information.
Gets the shortdoc for the given task module
.
Returns the shortdoc or nil
.
Returns true
if given module is a task.
Returns the task name for the given module
.
Link to this section Callbacks
A task needs to implement run
which receives
a list of command line args.