YoutubeOraclesTester2.sol

/*
   Youtube video views

   This contract keeps in storage a views counter
   for a given Youtube video.
*/


pragma solidity ^0.4.0;
import "github.com/oraclize/ethereum-api/oraclizeAPI.sol";

interface OracleDataReceiver {
    function __oracle_callback(string result);
}

contract YoutubeViewsOracle is usingOraclize {
    string internal apiKey;
    mapping(bytes32 => OracleDataReceiver) internal clients;
    
    event newOraclizeQuery(string description);
    event newYoutubeViewsCount(string views);

    function YoutubeViewsOracle() payable public {
        apiKey = 'API_KEY'; // TODO: Get from constructor's parameter and encrypt
    }
    
    function () public payable {}
    
    function __callback(bytes32 myid, string result) public {
        if (msg.sender != oraclize_cbAddress()) throw;
        newYoutubeViewsCount(strConcat(bytes32ToString(myid), " query result: ", result));
        clients[myid].__oracle_callback(result);
    }
    
    function update(string videoId) public payable returns (bytes32) {
        string memory url = strConcat('json(https://www.googleapis.com/youtube/v3/videos?part=statistics&id=', videoId, '&key=', apiKey, ').items.0.statistics.viewCount');
        bytes32 oqid = oraclize_query('URL', url);
        newOraclizeQuery(strConcat("Oraclize query ", bytes32ToString(oqid), " was sent, standing by for the answer..."));
        clients[oqid] = OracleDataReceiver(msg.sender);
        return oqid;
    }
    
    // From https://ethereum.stackexchange.com/questions/2519/how-to-convert-a-bytes32-to-string
    function bytes32ToString(bytes32 x) pure returns (string) {
        bytes memory bytesString = new bytes(32);
        uint charCount = 0;
        for (uint j = 0; j < 32; j++) {
            byte char = byte(bytes32(uint(x) * 2 ** (8 * j)));
            if (char != 0) {
                bytesString[charCount] = char;
                charCount++;
            }
        }
        bytes memory bytesStringTrimmed = new bytes(charCount);
        for (j = 0; j < charCount; j++) {
            bytesStringTrimmed[j] = bytesString[j];
        }
        return string(bytesStringTrimmed);
    }
    
}
//url = strConcat('json(https://www.googleapis.com/youtube/v3/videos?part=statistics&id=', videoId, '&key=', apiKey, ').items.0.statistics.likeCount');

contract YoutubeOraclesTester {
    uint public views;
    //uint public likes;
    YoutubeViewsOracle yvOracle;
    //YoutubeLikesOracle ylOracle;
    
    function YoutubeOraclesTester() public {
        yvOracle = new YoutubeViewsOracle(); // Also may be passed as parameter
        //ylOracle = new YoutubeLikesOracle();
    }
    
    function updateYoutubeStats(string videoId) public {
        yvOracle.update(videoId);
        //ylOracle.update(videoId);
    }
    
    function __oracle_callback(string result) public {
        if (msg.sender == address(yvOracle)) {
            views = parseInt(result);
        //} else if (msg.sender == address(ylOracle)) {
        //    likes = parseInt(result);
        } else {
            throw;
        }
    }
    
    // From OraclizeAPI
    function parseInt(string _a) internal returns (uint) {
        return parseInt(_a, 0);
    }
    
    // From OraclizeAPI
    function parseInt(string _a, uint _b) internal returns (uint) {
        bytes memory bresult = bytes(_a);
        uint mint = 0;
        bool decimals = false;
        for (uint i=0; i<bresult.length; i++){
            if ((bresult[i] >= 48)&&(bresult[i] <= 57)){
                if (decimals){
                   if (_b == 0) break;
                    else _b--;
                }
                mint *= 10;
                mint += uint(bresult[i]) - 48;
            } else if (bresult[i] == 46) decimals = true;
        }
        if (_b > 0) mint *= 10**_b;
        return mint;
    }

}