Empty array when adding members with mapping

Question

I had a question. I have a mapping that maps to struct.

  contract A{

    struct struct1{
      //...members...
    }

    struct struct2{
      struct1 input1;
    }

    mapping (uint => struct1) mapToStruct;

    struct2[] allEntries;
      //...rest of the code for populating mapToStruct        
    }

  contract B is A{

    function addToStruct2(uint _mappingNumber) returns(bool status){
      struct2 memory newMember;
      struct1 memory newEntry;
      newEntry = mapToStruct[_mappingNumber];
      newMember.input1 = newEntry;
      allEntries.push(newMember);
      return true;
    }
  }

But this code is not working, I am not able to add the details to allEntries. The array has a new entry but all its members are 0, even after addToStruct2 returns true. Thanks in advance

Answer 1

I got fairly tangled up when I first started debugging this. The nested structs seem unnecessarily busy. I would incline toward a well-solved pattern. Have a look at some basic patterns over here: Are there well-solved and simple storage patterns for Solidity?

I think you can use "mapping with structs", "array of structs with unique Id" or even "mapping with structs and delete" - a sort of swiss army knife pattern for a lot of cases.

Hope it helps.

Update

This will let you send a key and two inputs and store the data. You can get a key count and fetch the keys by number. You can fetch the stoed inputs using a valid key. When you fetch an unknown key, isSet will be false.

contract Simple {

  struct MyStruct {
    uint input1;
    uint input2;
    bool isSet;
  }

  mapping(bytes32 => MyStruct) public myStructs;
  bytes32[] public keys;

  function addToData(bytes32 key, uint input1, uint input2)
    public
    returns(bool success)
  {
    myStructs[key].input1 = input1;
    myStructs[key].input2 = input2;
    myStructs[key].isSet  = true;
    keys.push(key);
    return true;
  }

  function getKeyCount()
    public
    constant
    returns(uint keyCount)
  {
    return keys.length;
  }

}