数字资产交易
============

代码样例参看：contractsdk/go/example/erc721.go

或使用超级链XuperOS，其已发布丰富的合约模板，涵盖溯源、存证、积分、去中心化等多行业模板。 `点击了解 <https://xchain.baidu.com/n/console#/xuperos/contracts?type=market>`_ 

ERC721简介
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ERC721是数字资产合约,交易的商品是非同质性商品。其中，每一份资产，也就是token_id都是独一无二的类似收藏品交易。

ERC721具备哪些功能
------------------

- 通过initialize方法，向交易池注入自己的token_id
    - 注意token_id必须是全局唯一
- 通过invoke方法，执行不同的交易功能
    - transfer: userA将自己的某个收藏品token_id转给userB
    - approve: userA将自己的某个收藏品token_id的售卖权限授予userB
    - transferFrom: userB替userA将赋予权限的收藏品token_id卖给userC
    - pproveAll: userA将自己的所有收藏品token_id的售卖权限授予userB
- 通过query方法，执行不同的查询功能
    - balanceOf: userA的所有收藏品的数量
    - totalSupply: 交易池中所有的收藏品的数量
    - approvalOf: userA授权给userB的收藏品的数量

调用json文件示例
----------------

Initialize

./xchain-cli wasm invoke -a '下面json中args字段的内容' --method initialize -H localhost:37101 erc721

.. code-block:: python
    :linenos:

    {
        "module_name": "native",      # native或wasm
        "contract_name": "erc721",    # contract name
        "method_name": "initialize",  # initialize or query or invoke
        "args": {
            "from": "dudu",           # userName
            "supply": "1,2"           # token_ids
        }
    }

Invoke

./xchain-cli native invoke -a 'args内容' --method invoke -H localhost:37101 erc721

.. code-block:: python
    :linenos:

    {
        "module_name": "native",      # native或wasm
        "contract_name": "erc721",    # contract name
        "method_name": "invoke",      # initialize or query or invoke
        "args": {
            "action": "transfer",     # action name
            "from": "dudu",           # usera
            "to": "chengcheng",       # userb
            "token_id": "1"           # token_ids
        }
    }
    {
        "module_name": "native",      # native或wasm
        "contract_name": "erc721",    # contract name
        "method_name": "invoke",      # initialize or query or invoke
        "args": {
            "action": "transferFrom", # action name
            "from": "dudu",           # userA
            "caller": "chengcheng",   # userB
            "to": "miaomiao",         # userC
            "token_id": "1"           # token_ids
        }
    }
    {
        "module_name": "native",      # native或wasm
        "contract_name": "erc721",    # contract name
        "method_name": "invoke",      # initialize or query or invoke
        "args": {
            "action": "approve",      # action name
            "from": "dudu",           # userA
            "to": "chengcheng",       # userB
            "token_id": "1"           # token_ids
        }
    }

Query

./xchain-cli native query -a 'args内容' --method query -H localhost:37101 erc721

.. code-block:: python
    :linenos:

    {
        "module_name": "native",     # native或wasm
        "contract_name": "erc721",   # contract name
        "method_name": "query",      # initialize or query or invoke
        "args": {
            "action": "balanceOf",   # action name
            "from": "dudu"           # userA
        }
    }
    {
        "module_name": "native",     # native或wasm
        "contract_name": "erc721",   # contract name
        "method_name": "query",      # initialize or query or invoke
        "args": {
            "action": "totalSupply"  # action name
        }
    }
    {
        "module_name": "native",      # native或wasm
        "contract_name": "erc721",    # contract name
        "method_name": "query",       # initialize or query or invoke
        "args": {
            "action": "approvalOf",   # action name
            "from": "dudu",           # userA
            "to": "chengcheng"        # userB
        }
    }