/// <summary>
/// Creates a <see cref="Page"/> which is a sliced view of
/// the data source. This method first looks for the datasource
/// in the <see cref="System.Web.Caching.Cache"/> and if not found,
/// it invokes the <c>dataObtentionCallback</c> and caches the result
/// using the specifed <c>cacheKey</c>
/// </summary>
/// <param name="cacheKey">Cache key used to query/store the datasource</param>
/// <param name="pageSize">Page size</param>
/// <param name="dataObtentionCallback">Callback to be used to populate the cache</param>
/// <returns>A <see cref="Page"/> instance</returns>
public static Page CreateCachedPagination(String cacheKey, int pageSize, DataObtentionDelegate dataObtentionCallback)
{
IList datasource = (IList)CurrentContext.Cache[cacheKey];
if (datasource == null)
{
datasource = dataObtentionCallback();
CurrentContext.Cache.Insert(
cacheKey, datasource, null,
DateTime.MaxValue, TimeSpan.FromSeconds(10));
}
return(CreatePagination(datasource, pageSize));
}
/// <summary>
/// Creates a <see cref="Page"/> which is a sliced view of
/// the data source. This method first looks for the datasource
/// in the <see cref="System.Web.Caching.Cache"/> and if not found,
/// it invokes the <c>dataObtentionCallback</c> and caches the result
/// using the specifed <c>cacheKey</c>
/// </summary>
/// <param name="engineContext">The engine context.</param>
/// <param name="cacheKey">Cache key used to query/store the datasource</param>
/// <param name="pageSize">Page size</param>
/// <param name="dataObtentionCallback">Callback to be used to populate the cache</param>
/// <returns>A <see cref="Page"/> instance</returns>
/// <remarks>
/// CreateCachedPagination is quite dangerous exactly because the cache is
/// shared. If the results vary per logged user, then the programmer must
/// rather pay a lot of attention when generating the cache key.
/// It is preferable to have caching happen at a lower level of the stack, for example the NHibernate query cache.
/// </remarks>
public static IPaginatedPage CreateCachedPagination(IEngineContext engineContext, String cacheKey, int pageSize,
DataObtentionDelegate dataObtentionCallback)
{
var cacheProvider = engineContext.Services.CacheProvider;
var datasource = (IList)cacheProvider.Get(cacheKey);
if (datasource == null)
{
datasource = dataObtentionCallback();
cacheProvider.Store(cacheKey, datasource);
}
return(CreatePagination(engineContext, datasource, pageSize));
}
