Contract of contracts

Question

I am new to solidity :) and try to encapsulate array of contracts in one contract.

Something like this:

contract Item{
     uint public blabla1;
     uint public blabla2;
}

contract Collection{
    Item[]public items;
}

How can I do it? Any workarounds?

Answer 1

I updated your code with examples of creating array of contracts, passing data and reading that:

pragma solidity ^0.6.0;

contract Item {
     uint public blabla1;
     uint public blabla2;
     
     constructor(uint _blabla1, uint _blabla2) public {
         blabla1 = _blabla1;
         blabla2 = _blabla2;
     }
     
     function returnData() view public returns(uint, uint) {
         return (blabla1, blabla2);
     }
}

contract Collection {
    Item[]public items;
    
    function addItemContract(uint _blabla1, uint _blabla2) public {
        items.push(new Item(_blabla1, _blabla2));
    }
    
    function readItemContract(uint _index) public view returns(uint, uint) {
        return Item(items[_index]).returnData();
    }
}

Method addItemContract in contract Collection is creating contract Item, passing arguments to it and pushing it to array items.

Now that we know items is array of contract addresses, we can create instance with Item(<CONTRACT_ADDRESS>) and read the data of the contract which was earlier pushed into the array.

So yes, this is pretty much how to create and save new contracts into arrays and write or read their state.