View Source Goal (goal v0.0.1)
Validate parameters using a rules schema.
The parameters can be any map, and can be string-based or atom-based. Goal uses the validation
rules from in Ecto.Changeset
, which means you can use any validation that is available for
database fields for validating parameters with Goal.
A common use-case is parsing and validating parameters from Phoenix controllers:
defmodule MyApp.SomeController do
import Goal
@schema %{
id: [format: :uuid, required: true],
name: [min: 3, max: 20, required: true]
}
def create(conn, params) do
with {:ok, attrs} <- validate_params(params, @schema) do
...
end
end
end
defining-validations
Defining validations
Define field types with :type
:
:string
:integer
:boolean
:float
:decimal
:date
:time
:map
{:array, inner_type}
, whereinner_type
can be any of the field types- See Ecto.Schema for the full list
The default field type is :string
. That means you don't have to define this field in the schema
if the value will be a string.
Define map fields with :properties
.
Define string validations:
:equals
, string value:is
, string length:min
, minimum string length:max
, maximum string length:trim
, boolean to remove leading and trailing spaces:squish
, boolean to trim and collapse spaces:format
, atom to define the regex (available are::uuid
,:email
,:password
,:url
)
Define integer validations:
:is
, integer value:min
, minimum integer value:max
, maximum integer value:greater_than
, minimum integer value:less_than
, maximum integer value:greater_than_or_equal_to
, minimum integer value:less_than_or_equal_to
, maximum integer value:equal_to
, integer value:not_equal_to
, integer value
Define enum validations:
:excluded
, list of disallowed values:included
, list of allowed values:subset
, list of values
bring-your-own-regex
Bring your own regex
Goal has sensible defaults for string format validation. If you'd like to use your own regex, e.g. for validating email addresses or passwords, you can add your own regex in your application configuration.
config :goal,
uuid_regex: ~r/^[[:alpha:]]+$/,
email_regex: ~r/^[[:alpha:]]+$/,
password_regex: ~r/^[[:alpha:]]+$/,
url_regex: ~r/^[[:alpha:]]+$/
deeply-nested-maps
Deeply nested maps
Goal efficiently builds error changesets for nested maps. There is no limitation on depth. If the schema is becoming too verbose, you could consider splitting up the schema into reusable components.
data = %{
"nested_map" => %{
"map" => %{
"inner_map" => %{
"list" => [1, 2, 3]
}
}
}
}
schema = %{
nested_map: [
type: :map,
properties: %{
inner_map: [
type: :map,
properties: %{
map: [
type: :map,
properties: %{
list: [type: {:array, :integer}]
}
]
}
]
}
]
}
iex(1)> data = %{...}
iex(2)> schema = %{...}
iex(3)> Goal.validate_params(data, schema)
{:ok, %{nested_map: %{inner_map: %{map: %{list: [1, 2, 3]}}}}}
human-readable-error-messages
Human-readable error messages
Use Goal.traverse_errors/2
to build readable errors. Ecto and Phoenix by default
use Ecto.Changeset.traverse_errors/2
, which works for embedded Ecto schemas but not for the
plain nested maps used by Goal.
def translate_errors(changeset) do
Goal.traverse_errors(changeset, &translate_error/1)
end
credits
Credits
This library is based on Ecto and I had to copy and adapt
Ecto.Changeset.traverse_errors/2
. Thanks for making such an awesome library! 🙇
Link to this section Summary
Functions
Traverses changeset errors and applies the given function to error messages.
Validates the parameters against a schema.
Link to this section Types
Link to this section Functions
@spec traverse_errors( Ecto.Changeset.t(), (error() -> binary()) | (Ecto.Changeset.t(), atom(), error() -> binary()) ) :: %{required(atom()) => [term()]}
Traverses changeset errors and applies the given function to error messages.
examples
Examples
iex> traverse_errors(changeset, fn {msg, opts} ->
...> Regex.replace(~r"%{(\w+)}", msg, fn _, key ->
...> opts |> Keyword.get(String.to_existing_atom(key), key) |> to_string()
...> end)
...> end)
%{title: ["should be at least 3 characters"]}
@spec validate_params(data(), schema()) :: {:ok, map()} | {:error, Ecto.Changeset.t()}
Validates the parameters against a schema.
examples
Examples
iex> validate_params(%{"email" => "jane@example.com"}, %{email: [format: :email]})
{:ok, %{email: "jane@example.com"}}
iex> validate_params(%{"email" => "invalid"}, %{email: [format: :email]})
{:error, %Ecto.Changeset{valid?: false, errors: [email: {"has invalid format", ...}]}}