Request Method
Initiates an Oracle request.
Namespace: Neo.SmartContract.Framework.Native
Assembly: Neo.SmartContract.Framework
Syntax#
public static extern void Request(string url, string filter, string callback, object userData, long gasForResponse);Parameters：
- url: The request Url
- filter: Filter, used to filter useless data
- callback: Callback function
- userData: Additional data provided by the user
- long: The cost of getting a response
Example#
namespace demo{ [DisplayName("Oracle Demo")] [ManifestExtra("Author", "Neo")] [ManifestExtra("Email", "dev@neo.org")] [ManifestExtra("Description", "This is a Oracle contract example")] public class OracleDemo: SmartContract { static readonly string PreResponseData = "ResponseData";
/// <summary> /// Create a request. /// </summary> /// <param name="url">URL，e.g."http://127.0.0.1:8080/test"</param> /// <param name="filter">Filter,e.g."$.value"; JSONPath, { "value": "hello world" }</param> /// <param name="callback">Callback method,e.g."callback"</param> /// <param name="userData">User data,e.g.new byte[0]</param> /// <param name="gasForResponse">Gas for response,e.g.10000000</param> public static void Request(string url,string filter,string callback,byte[] userData,long gasForResponse) { Oracle.Request(url, filter, callback, userData, gasForResponse); }
/// <summary> /// Callback method /// </summary> /// <param name="url">Url</param> /// <param name="userData">User data</param> /// <param name="code">Response status</param> /// <param name="result">Result data</param> public static void Callback(string url, byte[] userData, int code, byte[] result) { Storage.Put(Storage.CurrentContext, PreResponseData, result.ToByteString()); } public static string GetData() { return Storage.Get(Storage.CurrentContext, PreResponseData); } }}