Pipelining data to reduce Ajax calls for paging
cacheUpper ) {
// outside cached data - need to make a request
ajax = true;
}
else if ( JSON.stringify( request.order ) !== JSON.stringify( cacheLastRequest.order ) ||
JSON.stringify( request.columns ) !== JSON.stringify( cacheLastRequest.columns ) ||
JSON.stringify( request.search ) !== JSON.stringify( cacheLastRequest.search )
) {
// properties changed (ordering, columns, searching)
ajax = true;
}
// Store the request for checking next time around
cacheLastRequest = $.extend( true, {}, request );
if ( ajax ) {
// Need data from the server
if ( requestStart < cacheLower ) {
requestStart = requestStart - (requestLength*(conf.pages-1));
if ( requestStart < 0 ) {
requestStart = 0;
}
}
cacheLower = requestStart;
cacheUpper = requestStart + (requestLength * conf.pages);
request.start = requestStart;
request.length = requestLength*conf.pages;
// Provide the same `data` options as DataTables.
if ( typeof conf.data === 'function' ) {
// As a function it is executed with the data object as an arg
// for manipulation. If an object is returned, it is used as the
// data object to submit
var d = conf.data( request );
if ( d ) {
$.extend( request, d );
}
}
else if ( $.isPlainObject( conf.data ) ) {
// As an object, the data given extends the default
$.extend( request, conf.data );
}
return $.ajax( {
"type": conf.method,
"url": conf.url,
"data": request,
"dataType": "json",
"cache": false,
"success": function ( json ) {
cacheLastJson = $.extend(true, {}, json);
if ( cacheLower != drawStart ) {
json.data.splice( 0, drawStart-cacheLower );
}
if ( requestLength >= -1 ) {
json.data.splice( requestLength, json.data.length );
}
drawCallback( json );
}
} );
}
else {
json = $.extend( true, {}, cacheLastJson );
json.draw = request.draw; // Update the echo for each response
json.data.splice( 0, requestStart-cacheLower );
json.data.splice( requestLength, json.data.length );
drawCallback(json);
}
}
};
// Register an API method that will empty the pipelined data, forcing an Ajax
// fetch on the next draw (i.e. `table.clearPipeline().draw()`)
$.fn.dataTable.Api.register( 'clearPipeline()', function () {
return this.iterator( 'table', function ( settings ) {
settings.clearCache = true;
} );
} );
//
// DataTables initialisation
//
$(document).ready(function() {
$('#example').DataTable( {
"processing": true,
"serverSide": true,
"ajax": $.fn.dataTable.pipeline( {
url: 'scripts/server_processing.php',
pages: 5 // number of pages to cache
} )
} );
} );
]]>