ここでは、JSONPが間違いなく最善のOPTIONS
方法であり、サーバー側のコードでメソッドを許可する必要がある場合は、これと同様のコードを実装できます。(注:この例は技術的にはMVC用ですが、適応させることができます。)
public class AllowCrossSiteJsonAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache);
HttpContext.Current.Response.Cache.SetNoStore();
filterContext.RequestContext.HttpContext.Response.AppendHeader("Access-Control-Allow-Origin", "*");
string rqstMethod = HttpContext.Current.Request.Headers["Access-Control-Request-Method"];
if (rqstMethod == "OPTIONS" || rqstMethod == "POST")
{
filterContext.RequestContext.HttpContext.Response.AppendHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
filterContext.RequestContext.HttpContext.Response.AppendHeader("Access-Control-Allow-Headers", "X-Requested-With, Accept, Access-Control-Allow-Origin, Content-Type");
}
base.OnActionExecuting(filterContext);
}
}
[HttpGet]
[AllowCrossSiteJsonAttribute]
public JsonpResult CommunicateCard(CommunicateCardModel ccm)
{
return ModelState.IsValid
? this.ValidCommunicateCardBuilder(ccm)
: this.InvalidFormSummary(ccm);
}
補足:これが私が使用しているJsonpResultです。素晴らしい作品。
namespace System.Web.Mvc
{
#region usings
using System;
using WebService.Attributes;
using WebService.Domain.Models;
using WebService.Exceptions;
using WebService.Models.ViewModels;
using Extensions;
using WebService.Utilities;
#endregion
public class JsonpResult : ActionResult
{
public Object Data { get; set; }
public string JsonCallback { get; set; }
public bool? Success { get; set; }
public override void ExecuteResult(ControllerContext context)
{
// Create a JsonResponse that we can Send out
// Check for the callback parameter
this.JsonCallback = context.HttpContext.Request["callback"];
// if the "callback" doesn't exist, we want to check for "jsoncallback"
if (string.IsNullOrEmpty(this.JsonCallback))
this.JsonCallback = context.HttpContext.Request["jsoncallback"];
// If we've made it this far, we know that the object sent is an
// object that we can serialize and Send back as valid JSON. We now
// need to wrap it in our JsonViewModel for consistancy. NOTE: We're
// using the AsList() extension method to ensure that we're
// returning an Array since our application (Sencha Touch) requires
// all data to be in array format.
if (!Data.GetType().IsGenericType)
Data = Data.AsList();
// Until now we the data is either an ERROR, or null
// if it's null, and the Data is not null, we set Success = true
// If Success is false, it's because we set it to false when we threw an error
// if that's the case, we keep it false for the client.
if (Success == null) Success = true;
var jsonViewModel = new JsonViewModel
{
results = this.Data,
// We know that Success is either True or False so we can
// safely cast the nullable bool to a bool.
success = (bool)this.Success
};
WriteOut(jsonViewModel, context);
}
/// <summary>
/// Write Out the JsonP Response to the Controller.
/// </summary>
/// <param name="jsonResponse">The unserialized object</param>
/// <param name="context">Controller Context</param>
private void WriteOut(JsonViewModel jsonResponse, ControllerContext context)
{
var response = context.HttpContext.Response;
response.ContentType = "application/javascript";
response.Write(JsonUtility.Serialize(jsonResponse, this.JsonCallback));
}
}
/// <summary>
/// extension methods for the controller to allow jsonp.
/// </summary>
public static class ContollerExtensions
{
public static JsonpResult Jsonp(this Controller controller, Object data)
{
return new JsonpResult { Data = data };
}
public static JsonpResult Jsonp(this Controller controller, Object data, bool success)
{
// We don't ever want to pass in a "true" success. We only want to
// know if it failed.
if (success)
{
return new JsonpResult { Data = data };
}
return new JsonpResult { Success = false, Data = data };
}
}
}