How to get all my users stored in a smart contract in aim to display themn into a Dapp?

Question

Let's consider the following:

struct SkillStruct{
  bytes32 skillName;
  uint index;
}

struct UserStruct {
  bytes32 userEmail;
  bytes32 userFirstname;
  bytes32 userLastname;
  uint index;
  uint amount; //amount of ECR token
  address[] userSkills;
}

mapping(address => UserStruct) private userStructs;
address[] private userIndex;

mapping(address => SkillStruct) private skillStructs;
address[] private skillIndex;

Is there a way to display all my users and theirs skills in an HTML list in my Dapp ? How can I process to get all my users ? What's the best for doing that ?

I tried to get inspired by https://www.cryptokitties.co/ source code, but all I found is a function to return kitten one by one but not all of them.

The only clue I see right now is to call a function to get users.length and then in an asynchronous loop call the getUser() function as many times as there are users. And then maybe use caching or localstorage to store them into the browser.

Is there a better way ??

Thanks u all

Answer 1

You can't return an array of structs from Solidity. Additionally, you would not want to traverse an array of structs that which could grow in size so much that gas limits would not allow the function to process.

What you could do is what you were mentioning in your question. Create a function that given an array index returns a single struct and then call that function for each element in the array (you'd probably want to do some pagination).