com.biffweb.core — com.biffweb/core 2.0.0-rc2

Helper code and schemas for the interfaces shared by all Biff libraries.

SCHEMA

:biff.core/init (fn [modules-var]) => {...}

See biff.core/start.

:biff.core/stop (fn []) => nil

See biff.core/start and biff.core/stop.

:biff.core/secret A Delay-like value returned by biff.core/secret-delay

:biff.core/kv-set (fn [ctx namespace key value]) => nil

Sets the given key in namespace to value. A nil value should delete the key, i.e. a call to :biff.core/kv-list should only return keys with non-nil values.

namespace Qualified keyword, e.g. :com.example/things. The keyword's namespace should be owned by whatever library or application defines the keyword.

key String.

value Any Clojure value that can be round-tripped through pr-str -> clojure.edn/read-string without custom options.

:biff.core/kv-get (fn [ctx namespace key]) => value

Returns the value for the given key in namespace. If key is unset, returns nil. See :biff.core/kv-set.

:biff.core/kv-list (fn [ctx namespace]), (fn [ctx namespace key-prefix]), => [key1, key2, ...]

Returns a sequence of sorted keys in the given namespace. See :biff.core/kv-set.

key-prefix String. If set, returns only the keys beginning with this prefix.

get-registry clj

(get-registry)

Returns all schemas that have been passed to biff.core/register.

(biff.core/get-registry) => {:person/display-name :string :person/age :int}

register clj

(register schemas)

Merges a map of Malli schemas into Biff's global schema registry.

(biff.core/register {:person/display-name :string :person/age :int})

Registered schemas are used by biff.core/validate.

secret-delay clj

(secret-delay x)

Wraps x in a Delay that doesn't show its value when serialized.

(def my-api-key (secret-delay "my-api-key")) (str my-api-key) => "#<SecretDelay: redacted>"

(force my-api-key) => "my-api-key"

force is recommended for unwrapping secrets (instead of deref / @) so that nil values don't cause an exception.

For backwards compatibility, the returned value can also be unwrapped by calling it as a function:

(my-api-key) => "my-api-key"

Biff libraries expect secrets to be wrapped like this to help prevent leaking secrets (e.g. in logs).

Note that this is a function, not a macro, and thus the arguments are evaluated immediately, unlike a normal Delay.

start clj

(start modules-var components)

(start initial-system modules-var components)

Starts a Biff application and returns the system map.

(def modules [...]) (def components [...]) (biff.core/start #'modules components)

Calls any :biff.core/init functions in modules and merges the results in order to create an initial system map. If you passed initial-system, it will be merged into this system map. Then the system map is passed through each component.

:biff.core/init is a function that receives the modules var, aggregates keys from other modules and/or initializes other values as needed, and returns the results as part of a partial system map. For values that should be updated when modules-var is updated (without restarting the system), :biff.core/init can wrap them with a function that's memoized based on the value of modules-var:

(def get-foo (memoize (fn [modules] (aggregate-foos (keep :example/foo modules)))))

{:biff.core/init (fn [modules-var] {:example/get-foo #(get-foo @modules-var)})}

Each component is a function that receives the system map, starts stateful resources or does other initialization as needed, and returns an updated system map. Components can add stop functions (zero-arg functions that stop a stateful resource) to the end of the :biff.core/stop vector. :biff/stop is also recognized for backwards compatibility.

Uses biff.core/validate to ensure that keys in modules, keys returned by :biff.core/init, and keys returned by components are valid.

stop clj

(stop system)

Stops a Biff application.

Calls the :biff.core/stop functions from system in reverse order.

validate clj macro

(validate m & {:keys [required extra-schema]})

Throws an AssertionError if any values in m don't match the registered schemas for their key. Returns m.

(biff.core/register {:person/age :int}) (biff.core/validate {:person/age "three"}) ; => ; (err) :person/age "three" is invalid: should be an integer

:required A sequence of keys. Throws an error if any of these aren't present in m.

:extra-schema A map of Malli schemas. Can be used to define schema without modifying the global registry by calling biff.core/register.

For convenience, m can be a sequence of maps instead of a single map.