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Complex controller

Create a controller with balance and token ownership checks.

A more complex controller can provision write access in, really, any way you'd like! This example contract does a few things:

  • Checks the sender has sent some required value in order to execute the query (e.g., pay 1 ETH to mutate data).
  • Checks ownership of some token at _foos and _bars, each which have a token ID in a table such that your WHERE clause will include a foo_id and bar_id column, respectively.
  • If these checks pass, only allow an update and restrict it to a specific column like baz, but only if the supplied value is passes a check of being > 0.

If you can program the rules in a smart contract, you can program how data is mutated.

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.10 <0.9.0;

import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {TablelandController} from "@tableland/evm/contracts/TablelandController.sol";
import {TablelandPolicy} from "@tableland/evm/contracts/TablelandPolicy.sol";
import {Policies} from "@tableland/evm/contracts/policies/Policies.sol";
import {ERC721EnumerablePolicies} from "@tableland/evm/contracts/policies/ERC721EnumerablePolicies.sol";
import {ERC721AQueryablePolicies} from "@tableland/evm/contracts/policies/ERC721AQueryablePolicies.sol";

contract ComplexController is TablelandController, Ownable {
error InsufficientValue(uint256 receivedValue, uint256 requiredValue);

uint256 public constant REQUIRED_VALUE = 1 ether;

address private _foos;
address private _bars;

function getPolicy(
address caller,
) public payable override returns (TablelandPolicy memory) {
// Enforce some ether and revert if insufficient
if (msg.value < 1 ether) {
revert InsufficientValue(msg.value, REQUIRED_VALUE);

// The following line is for coverage of a revert/require error
require(msg.value == 1 ether, "too much ether!");

string[] memory whereClauses = new string[](2);
string[] memory withChecks = new string[](3);

// Require one of FOO
whereClauses[0] = ERC721EnumerablePolicies.getClauseForRequireOneOf(

// Require one of BAR
whereClauses[1] = ERC721AQueryablePolicies.getClauseForRequireOneOf(

// Restrict updates to a single column
string[] memory updatableColumns = new string[](1);
updatableColumns[0] = "baz";

// Include a check on the incoming data
withChecks[0] = ""; // included to filter in Policies.joinClauses
withChecks[1] = "baz > 0";
withChecks[2] = ""; // included to filter in Policies.joinClauses

// Return policy
allowInsert: false,
allowUpdate: true,
allowDelete: false,
whereClause: Policies.joinClauses(whereClauses),
withCheck: Policies.joinClauses(withChecks),
updatableColumns: updatableColumns

function setFoos(address foos) external onlyOwner {
_foos = foos;

function setBars(address bars) external onlyOwner {
_bars = bars;