Central module for configurable validation limits.
All limits have sensible defaults and can be overridden at boot time via
config :gamend_core, Gamend.Limits, key: value or at runtime
via Application.put_env(:gamend_core, Gamend.Limits, [...]).
Environment variables
Each limit is a Gamend.Settings.Provider setting, so its env var name is
derived from the key with the GAMEND_LIMITS_ prefix, e.g.:
GAMEND_LIMITS_MAX_METADATA_SIZE=32768 -> :max_metadata_size
GAMEND_LIMITS_MAX_PAGE_SIZE=100 -> :max_page_sizeEnv vars are read once at boot by Gamend.Settings.from_env/0, which the
host's config/runtime.exs runs through GamendWeb.HostRuntime.config/2.
Usage in schemas
import Gamend.Limits, only: [get: 1, validate_metadata_size: 2]
changeset
|> validate_length(:title, max: Gamend.Limits.get(:max_group_title))
|> validate_metadata_size(:metadata)Usage in controllers
page_size = Gamend.Limits.clamp_page_size(params["page_size"])Summary
Functions
Returns a map of all limit keys and their current effective values.
Clamps a raw page parameter to [1, ∞). Same parsing logic as page_size.
Clamps a raw page_size parameter to [1, max_page_size]. Accepts nil, string, or integer. Returns integer.
Returns the compiled defaults map. Useful for the admin UI to display defaults vs. overrides.
Returns the current value for the given limit key.
Validates that a :map field, when serialized to JSON, does not exceed
max_metadata_size bytes. Add this to any changeset that casts a metadata
or arbitrary JSON map field.
Functions
@spec all() :: map()
Returns a map of all limit keys and their current effective values.
@spec clamp_page(any()) :: pos_integer()
Clamps a raw page parameter to [1, ∞). Same parsing logic as page_size.
Clamps a raw page_size parameter to [1, max_page_size]. Accepts nil, string, or integer. Returns integer.
@spec defaults() :: map()
Returns the compiled defaults map. Useful for the admin UI to display defaults vs. overrides.
Returns the current value for the given limit key.
Reads from Application.get_env(:gamend_core, Gamend.Limits) first,
falling back to the compiled default.
@spec validate_metadata_size(Ecto.Changeset.t(), atom(), atom()) :: Ecto.Changeset.t()
Validates that a :map field, when serialized to JSON, does not exceed
max_metadata_size bytes. Add this to any changeset that casts a metadata
or arbitrary JSON map field.
changeset
|> validate_metadata_size(:metadata)
|> validate_metadata_size(:value, :max_kv_value_size)