Metadata-Version: 2.1
Name: eip712-structs
Version: 0.1.6
Summary: UNKNOWN
Home-page: https://github.com/ajrgrubbs/py-eip712-structs
License: MIT
Description: # EIP-712 Structs  [![Build Status](https://travis-ci.org/ajrgrubbs/py-eip712-structs.svg?branch=master)](https://travis-ci.org/ajrgrubbs/py-eip712-structs)
        
        A python interface for simple EIP-712 struct construction.
        
        In this module, a "struct" is structured data as defined in the standard.
        It is not the same as the Python Standard Library's struct (e.g., `import struct`).
        
        Read the proposal:<br/>
        https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md
        
        #### Supported Python Versions
        - `3.6`
        - `3.7`
        
        ## Install
        ```bash
        pip install eip712-structs
        ```
        
        ## Basic Usage
        
        Our desired struct:
        ```
        struct Message {
            address to;
            string contents;
        }
        ```
        
        Python representation:
        ```python
        from eip712_structs import EIP712Struct, Address, String, make_domain, struct_to_message
        
        class Message(EIP712Struct):
            to = Address()
            contents = String()
            
        enctyp = Message.encode_type()  # 'Mail(address to,string contents)'
        
        msg = Message(to='0xdead...beef', contents='hello world')
        msg.encode_data()  # The struct's data in encoded form
        
        domain = make_domain(name='example')
        msg_body, signable_bytes = struct_to_message(msg, domain)
        
        # msg_body is a standardized dict with keys primaryType, types, domain, and message
        # suitable for converting to JSON for making requests
        
        # `signable bytes` is a deterministic bytes representation of the struct
        # Suitable for hashing or signing
        #   bytes 0-1: b'\x19\x01'
        #   bytes 2-33: domain separator (hash of domain type and data)
        #   bytes 34-65: hash of struct type and data
        ```
        
        #### Dynamic construction
        Attributes may be added dynamically as well. This may be necessary if you
        want to use a reserved keyword like `from`.
        
        ```python
        class Message(EIP712Struct):
            pass
        
        Message.to = Address()
        setattr(Message, 'from', Address())
        ```
        
        #### The domain separator
        Messages also require a domain struct. A helper method exists for this purpose.
        All values to the `make_domain()`
        function are optional - but at least one must be defined. If omitted, the resulting
        domain struct's definition leaves out the parameter entirely.
        
        The full signature: <br/>
        `make_domain(name: string, version: string, chainId: uint256, verifyingContract: address, salt: bytes32)`
        
        ```python
        from eip712_structs import EIP712Struct, String, make_domain, struct_to_message
        
        domain = make_domain(name='my_domain')
        
        class Foo(EIP712Struct):
            bar = String()
        
        foo = Foo(bar='baz')
        
        message_dict, message_hash = struct_to_message(foo, domain)
        ```
        
        
        ## Member Types
        
        ### Basic types
        EIP712's basic types map directly to solidity types.
        
        ```python
        from eip712_structs import Address, Boolean, Bytes, Int, String, Uint
        
        Address()  # Solidity's 'address'
        Boolean()  # 'bool'
        Bytes()    # 'bytes'
        Bytes(N)   # 'bytesN' - N must be an int from 1 through 32
        Int(N)     # 'intN' - N must be a multiple of 8, from 8 to 256
        String()   # 'string'
        Uint(N)    # 'uintN' - N must be a multiple of 8, from 8 to 256
        ```
        
        Use like:
        ```python
        class Foo(EIP712Struct):
            member_name_0 = Address()
            member_name_1 = Bytes(5)
            # ...etc
        ```
        
        ### Struct references
        In addition to holding basic types, EIP712 structs may also hold other structs!
        Usage is almost the same - the difference is you don't "instantiate" the class.
        
        Example:
        ```python
        class Dog(EIP712Struct):
            name = String()
            breed = String()
        
        class Person(EIP712Struct):
            name = String()
            dog = Dog  # Take note - no parentheses!
        
        Dog.encode_type()     # Dog(string name,string breed)
        Person.encode_type()  # Person(string name,Dog dog)Dog(string name,string breed)
        ```
        
        Instantiating the structs with nested values may be done like:
        
        ```python
        # Method one: set it to a struct
        dog = Dog(name='Mochi', breed='Corgi')
        person = Person(name='Ed', dog=dog)
        
        # Method two: set it to a dict - the underlying struct is built for you
        person = Person(
            name='Ed',
            dog={
                'name': 'Mochi',
                'breed': 'Corgi',
            }
        )
        ```
        
        ### Arrays
        Arrays are also supported for the standard.
        
        ```python
        array_member = Array(<item_type>[, <optional_length>])
        ```
        
        - `<item_type>` - The basic type or struct that will live in the array
        - `<optional_length>` - If given, the array is set to that length.
        
        For example:
        ```python
        dynamic_array = Array(String())      # String[] dynamic_array
        static_array  = Array(String(), 10)  # String[10] static_array
        struct_array = Array(MyStruct, 10)   # MyStruct[10] - again, don't instantiate structs like the basic types
        ```
        
        ## Development
        Contributions always welcome.
        
        Install dependencies:
        - `pip install -r requirements.txt && pip install -r test_requirements.txt`
        
        Run tests:
        - `python setup.py test`
        
Keywords: ethereum eip712
Platform: UNKNOWN
Description-Content-Type: text/markdown
