Module util-policies: Reference and API

This module is intended to be only used by policy developers. It contains some utility functions to make policy creation more easier and compliant.

Rank constants

Constants defined for standardizing ranks management in policies

(defconst RANK-HIGH-PRIORITY:integer 0)

(defconst RANK-SELLER-FEE:integer 10)

(defconst RANK-ROYALTY:integer 20)

(defconst RANK-SALE:integer 30)

(defconst RANK-LOG-PRIORITY:integer 99)

Message utils

These functions are helpers to read the data messages following the specification Passing data to policies

get-msg-data

domain string token object{token-info} default object → object

Read an optional message from data, trying to read:

  • per-token message

  • then fallback to a global message

  • and if nothing is available return the default as a fallback

enforce-get-msg-data

domain string token object{token-info} → object

Similar to get-msg-data but without default.

The message is mandatory. Make the transaction fail if not present.

Sales Message utils

Marmalade-NG defines a common message for sales, shared by all policies.

Definition:

(defschema sale-msg-sch
  sale_type:string ; Type of sale
  currency:module{fungible-v2} ; Currency of sale
)

Theses functions are helpers to read that specific message:

read-sale-msg

token object{token-info} → object{sale-msg-sch} Read the sale message or return an empty default if not present.

enforce-read-sale-msg

token object{token-info} → object{sale-msg-sch}

Read the sale message, but make the transaction fail if not present.

Other common utils

check-fungible-account

currency module{fungible-v2} acct string → bool

Check (and enforce) an account again a specific fungible currency.

  • The account name must be valid.

  • The account must exist.

check-price

currency module{fungible-v2} price decimal → bool

Check (and enforce) the validity of a price against a specific currency.

  • The price must be positive.

  • The price must must be compliant with the fungible precision.

enforce-valid-rate

rate decimal → bool

Utility function to enforce that a rate is valid.

  • between 0.0 and 1.0