/// <inheritdoc/>
public byte[] SerializeCacheItem <T>(CacheItem <T> value)
{
NotNull(value, nameof(value));
var jsonValue = this.Serialize(value.Value);
var jsonItem = JsonCacheItem.FromCacheItem(value, jsonValue);
return(this.Serialize(jsonItem));
}
/// <summary>
/// Handle request to convert data from remote url
/// </summary>
/// <remarks>
/// Example client: http://jsfiddle.net/s7UGv/4/
/// </remarks>
/// <param name="context">context of request/response</param>
/// <returns>Task</returns>
public async Task HandleRequest(IOwinContext context)
{
var uri = HttpUtility.UrlDecode(context.Request.Query["uri"]);
var callback = context.Request.Query["callback"];
var xml = string.Empty;
//see if we have the result cached
var jsonCache = Cache.Get(HttpUtility.UrlEncode(uri)) as JsonCacheItem;
if (jsonCache == null)
{
using (var httpClient = new HttpClient())
{
var response = await httpClient.GetAsync(uri);
xml = await response.Content.ReadAsStringAsync();
}
var json = await Converter.ConvertToJsonAsync(xml);
jsonCache = new JsonCacheItem(json);
//cache it...
Cache.Add(HttpUtility.UrlEncode(uri), jsonCache, DateTimeOffset.Now.AddMinutes(CACHE_DURATION_MINS));
}
//check If-None-Match header etag to see if it matches our data hash
else if (context.Request.Headers["If-None-Match"] == String.Concat("\"", jsonCache.Hash, "\""))
{
//if it does return 304 Not Modified
context.Response.StatusCode = 304;
return;
}
var result = string.Empty;
if (string.IsNullOrWhiteSpace(callback))
{
context.Response.ContentType = "application/json";
result = jsonCache.Data;
}
else
{
context.Response.ContentType = "application/javascript";
result = callback + "(" + jsonCache.Data + ");";
}
//set the response as cached for cache duration
context.Response.Headers["Cache-Control"] = string.Format("max-age={0}", CACHE_DURATION_MINS * 60);
//set etag
context.Response.ETag = String.Concat("\"", jsonCache.Hash, "\"");
await context.Response.WriteAsync(result);
}
public static async Task AddToCache(JsonCacheItem item, string key)
{
var storageFolder = ApplicationData.Current.LocalFolder;
await EnsureClearedKeyAsync(key);
await storageFolder.CreateFileAsync(key, CreationCollisionOption.ReplaceExisting);
var storageFile = await storageFolder.GetFileAsync(key);
await FileIO.WriteTextAsync(storageFile, item.JsonResult);
}
