Action

用于查询和发送Action的API。

EOS.IO的action定义如下：

struct action {
  scope_name scope; // the contract defining the primary code to execute for code/type
  action_name name; // the action to be taken
  permission_level[] authorization; // the accounts and permission levels provided
  bytes data; // opaque data processed by code
};

使用Action系列API，让你可以在合约中查看当前Action的字段，以便正确响应。

示例代码：

// Assume this action is used for the following examples:
// {
//  "code": "eos",
//  "type": "transfer",
//  "authorization": [{ "account": "inita", "permission": "active" }],
//  "data": {
//    "from": "inita",
//    "to": "initb",
//    "amount": 1000
//  }
// }

char buffer[128];
uint32_t total = read_action(buffer, 5); // buffer contains the content of the action up to 5 bytes
print(total); // Output: 5

uint32_t msgsize = action_size();
print(msgsize); // Output: size of the above action's data field

require_recipient(N(initc)); // initc account will be notified for this action

require_auth(N(inita)); // Do nothing since inita exists in the auth list
require_auth(N(initb)); // Throws an exception

print(current_time()); // Output: timestamp (in microseconds since 1970) of current block