defmodule Mix.Tasks.Phx.Gen.Schema do
@shortdoc "Generates an Ecto schema and migration file"
@moduledoc """
Generates an Ecto schema and migration.
$ mix phx.gen.schema Blog.Post blog_posts title:string views:integer
The first argument is the schema module followed by its plural
name (used as the table name).
The generated schema above will contain:
* a schema file in `lib/my_app/blog/post.ex`, with a `blog_posts` table
* a migration file for the repository
The generated migration can be skipped with `--no-migration`.
## Contexts
Your schemas can be generated and added to a separate OTP app.
Make sure your configuration is properly setup or manually
specify the context app with the `--context-app` option with
the CLI.
Via config:
config :marketing_web, :generators, context_app: :marketing
Via CLI:
$ mix phx.gen.schema Blog.Post blog_posts title:string views:integer --context-app marketing
## Attributes
The resource fields are given using `name:type` syntax
where type are the types supported by Ecto. Omitting
the type makes it default to `:string`:
$ mix phx.gen.schema Blog.Post blog_posts title views:integer
The following types are supported:
#{for attr <- Mix.Phoenix.Schema.valid_types(), do: " * `#{inspect attr}`\n"}
* `:datetime` - An alias for `:naive_datetime`
The generator also supports references, which we will properly
associate the given column to the primary key column of the
referenced table:
$ mix phx.gen.schema Blog.Post blog_posts title user_id:references:users
This will result in a migration with an `:integer` column
of `:user_id` and create an index.
Furthermore an array type can also be given if it is
supported by your database, although it requires the
type of the underlying array element to be given too:
$ mix phx.gen.schema Blog.Post blog_posts tags:array:string
Unique columns can be automatically generated by using:
$ mix phx.gen.schema Blog.Post blog_posts title:unique unique_int:integer:unique
Redact columns can be automatically generated by using:
$ mix phx.gen.schema Accounts.Superhero superheroes secret_identity:redact password:string:redact
Ecto.Enum fields can be generated by using:
$ mix phx.gen.schema Blog.Post blog_posts title status:enum:unpublished:published:deleted
If no data type is given, it defaults to a string.
## table
By default, the table name for the migration and schema will be
the plural name provided for the resource. To customize this value,
a `--table` option may be provided. For example:
$ mix phx.gen.schema Blog.Post posts --table cms_posts
## binary_id
Generated migration can use `binary_id` for schema's primary key
and its references with option `--binary-id`.
## prefix
By default migrations and schemas are generated without a prefix.
For PostgreSQL this sets the "SCHEMA" (typically set via `search_path`)
and for MySQL it sets the database for the generated migration and schema.
The prefix can be used to thematically organize your tables on the database level.
A prefix can be specified with the `--prefix` flags. For example:
$ mix phx.gen.schema Blog.Post posts --prefix blog
> #### Warning {: .warning}
>
> The flag does not generate migrations to create the schema / database.
> This needs to be done manually or in a separate migration.
## Default options
This generator uses default options provided in the `:generators`
configuration of your application. These are the defaults:
config :your_app, :generators,
migration: true,
binary_id: false,
sample_binary_id: "11111111-1111-1111-1111-111111111111"
You can override those options per invocation by providing corresponding
switches, e.g. `--no-binary-id` to use normal ids despite the default
configuration or `--migration` to force generation of the migration.
"""
use Mix.Task
alias Mix.Phoenix.Schema
@switches [migration: :boolean, binary_id: :boolean, table: :string,
web: :string, context_app: :string, prefix: :string]
@doc false
def run(args) do
if Mix.Project.umbrella?() do
Mix.raise "mix phx.gen.schema must be invoked from within your *_web application root directory"
end
schema = build(args, [])
paths = Mix.Phoenix.generator_paths()
prompt_for_conflicts(schema)
schema
|> copy_new_files(paths, schema: schema)
|> print_shell_instructions()
end
defp prompt_for_conflicts(schema) do
schema
|> files_to_be_generated()
|> Mix.Phoenix.prompt_for_conflicts()
end
@doc false
def build(args, parent_opts, help \\ __MODULE__) do
{schema_opts, parsed, _} = OptionParser.parse(args, switches: @switches)
[schema_name, plural | attrs] = validate_args!(parsed, help)
opts =
parent_opts
|> Keyword.merge(schema_opts)
|> put_context_app(schema_opts[:context_app])
schema = Schema.new(schema_name, plural, attrs, opts)
schema
end
defp put_context_app(opts, nil), do: opts
defp put_context_app(opts, string) do
Keyword.put(opts, :context_app, String.to_atom(string))
end
@doc false
def files_to_be_generated(%Schema{} = schema) do
[{:eex, "schema.ex", schema.file}]
end
@doc false
def copy_new_files(%Schema{context_app: ctx_app} = schema, paths, binding) do
files = files_to_be_generated(schema)
Mix.Phoenix.copy_from(paths, "priv/templates/phx.gen.schema", binding, files)
if schema.migration? do
migration_path = Mix.Phoenix.context_app_path(ctx_app, "priv/repo/migrations/#{timestamp()}_create_#{schema.table}.exs")
Mix.Phoenix.copy_from paths, "priv/templates/phx.gen.schema", binding, [
{:eex, "migration.exs", migration_path},
]
end
schema
end
@doc false
def print_shell_instructions(%Schema{} = schema) do
if schema.migration? do
Mix.shell().info """
Remember to update your repository by running migrations:
$ mix ecto.migrate
"""
end
end
@doc false
def validate_args!([schema, plural | _] = args, help) do
cond do
not Schema.valid?(schema) ->
help.raise_with_help "Expected the schema argument, #{inspect schema}, to be a valid module name"
String.contains?(plural, ":") or plural != Phoenix.Naming.underscore(plural) ->
help.raise_with_help "Expected the plural argument, #{inspect plural}, to be all lowercase using snake_case convention"
true ->
args
end
end
def validate_args!(_, help) do
help.raise_with_help "Invalid arguments"
end
@doc false
@spec raise_with_help(String.t) :: no_return()
def raise_with_help(msg) do
Mix.raise """
#{msg}
mix phx.gen.schema expects both a module name and
the plural of the generated resource followed by
any number of attributes:
mix phx.gen.schema Blog.Post blog_posts title:string
"""
end
defp timestamp do
{{y, m, d}, {hh, mm, ss}} = :calendar.universal_time()
"#{y}#{pad(m)}#{pad(d)}#{pad(hh)}#{pad(mm)}#{pad(ss)}"
end
defp pad(i) when i < 10, do: << ?0, ?0 + i >>
defp pad(i), do: to_string(i)
end
