Simple Voting Contract Hook

Simple Voting Contract Hook for Xahau Network

Installation

Hook is installed on one account, users send Invoke transaction to that account to vote for one of candidates.

HookOn triggers: ttINVOKE

Setup

To add new candidate send Invoke transaction from account which have this hook installed (self).

{
    "TransactionType": "Invoke",
    "Account": "rVotingaccount... (self)",
    "HookParameters": [
      {
        "HookParameter": {
          "HookParameterName": <uint8ToHex(0)>,
          "HookParameterValue": <uint16ToHex(1)>+<(convertStringToHex('Name of candidate 1').padEnd(64,'0'))>
        }
      },
      {
        "HookParameter": {
          "HookParameterName": <uint8ToHex(1)>,
          "HookParameterValue": <uint16ToHex(6)>+<(convertStringToHex('Name of candidate 6').padEnd(64,'0'))>
        }
      },
      ...
...

In each transaction HookParameterName starts with 0, this ensures hook treats parameters as array-like structure. HookParameterValue is coumpound data of UInt16 number in HEX - that is candidate ID, followed by candidate title (32 chars max).
Once executed, hookstate row will be added.

Voting

To vote on existing candidate ID, send Invoke transaction to account which have this hook installed.

{
    "TransactionType": "Invoke",
    "Account": "rVoter...",
    "HookParameters": [
      {
        "HookParameter": {
          "HookParameterName": <convertStringToHex("KEY")>,
          "HookParameterValue": <uint16ToHex(1)>
        }
      },
    ],
    "Destination": "rVotingaccount...",

HookParameterName - always "KEY" HookParameterValue - candidate ID in this sample "Name of candidate 1"

ABI for hookstates

{ 
  "name": "votinghook",
  "hook_account": "",
  "hook_namespace_id": "",
  "hook_definition": {
    "name": "votinghook",
    "description": "votinghook",
    "hook_hash": "",
    "version": [],
    "hook_states": {
      "name": "votinghook",
      "description": "votinghook",
      "fields": [
        {
          "name": "Candidates",
          "hookstate_key": [
            {
              "type": "Null",
              "name": "padding",
              "byte_length": 31,
              "exclude": true
            },
            {
              "type": "UInt8",
              "name": "ID",
              "exclude": false
            }
          ],
          "hookstate_data": [
            {
              "type": "VarString",
              "name": "Candidate name",
              "byte_length":32,
              "exclude":false
            },
            {
              "type":"UInt16",
              "name":"Number of votes"
            }
          ]
        },
        {
          "name": "Votes",
          "hookstate_key": [
            {
              "type": "Null",
              "name": "padding",
              "byte_length": 12,
              "exclude": true
            },
            {
              "type": "AccountID",
              "name": "Voter"
            }
          ],
          "hookstate_data": [
            {
              "type": "VarString",
              "name": "Candidate name",
              "byte_length":32,
              "exclude":false
            }
          ]
        }
      ]
    }
  }
}

Credit for creating hook: @tequdev