cccc/static/sg/slick.remotemodel.js

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2018-12-04 08:50:29 +00:00
(function ($) {
/***
* A sample AJAX data store implementation.
* Right now, it's hooked up to load Hackernews stories, but can
* easily be extended to support any JSONP-compatible backend that accepts paging parameters.
*/
function RemoteModel() {
// private
var PAGESIZE = 50;
var data = {length: 0};
var searchstr = "";
var sortcol = null;
var sortdir = 1;
var h_request = null;
var req = null; // ajax request
// events
var onDataLoading = new Slick.Event();
var onDataLoaded = new Slick.Event();
function init() {
}
function isDataLoaded(from, to) {
for (var i = from; i <= to; i++) {
if (data[i] == undefined || data[i] == null) {
return false;
}
}
return true;
}
function clear() {
for (var key in data) {
delete data[key];
}
data.length = 0;
}
function ensureData(from, to) {
if (req) {
req.abort();
for (var i = req.fromPage; i <= req.toPage; i++)
data[i * PAGESIZE] = undefined;
}
if (from < 0) {
from = 0;
}
if (data.length > 0) {
to = Math.min(to, data.length - 1);
}
var fromPage = Math.floor(from / PAGESIZE);
var toPage = Math.floor(to / PAGESIZE);
while (data[fromPage * PAGESIZE] !== undefined && fromPage < toPage)
fromPage++;
while (data[toPage * PAGESIZE] !== undefined && fromPage < toPage)
toPage--;
if (fromPage > toPage || ((fromPage == toPage) && data[fromPage * PAGESIZE] !== undefined)) {
// TODO: look-ahead
onDataLoaded.notify({from: from, to: to});
return;
}
var url = "http://api.thriftdb.com/api.hnsearch.com/items/_search?filter[fields][type][]=submission&q=" + searchstr + "&start=" + (fromPage * PAGESIZE) + "&limit=" + (((toPage - fromPage) * PAGESIZE) + PAGESIZE);
if (sortcol != null) {
url += ("&sortby=" + sortcol + ((sortdir > 0) ? "+asc" : "+desc"));
}
if (h_request != null) {
clearTimeout(h_request);
}
h_request = setTimeout(function () {
for (var i = fromPage; i <= toPage; i++)
data[i * PAGESIZE] = null; // null indicates a 'requested but not available yet'
onDataLoading.notify({from: from, to: to});
req = $.jsonp({
url: url,
callbackParameter: "callback",
cache: true,
success: onSuccess,
error: function () {
onError(fromPage, toPage)
}
});
req.fromPage = fromPage;
req.toPage = toPage;
}, 50);
}
function onError(fromPage, toPage) {
alert("error loading pages " + fromPage + " to " + toPage);
}
function onSuccess(resp) {
var from = resp.request.start, to = from + resp.results.length;
data.length = Math.min(parseInt(resp.hits),1000); // limitation of the API
for (var i = 0; i < resp.results.length; i++) {
var item = resp.results[i].item;
// Old IE versions can't parse ISO dates, so change to universally-supported format.
item.create_ts = item.create_ts.replace(/^(\d+)-(\d+)-(\d+)T(\d+:\d+:\d+)Z$/, "$2/$3/$1 $4 UTC");
item.create_ts = new Date(item.create_ts);
data[from + i] = item;
data[from + i].index = from + i;
}
req = null;
onDataLoaded.notify({from: from, to: to});
}
function reloadData(from, to) {
for (var i = from; i <= to; i++)
delete data[i];
ensureData(from, to);
}
function setSort(column, dir) {
sortcol = column;
sortdir = dir;
clear();
}
function setSearch(str) {
searchstr = str;
clear();
}
init();
return {
// properties
"data": data,
// methods
"clear": clear,
"isDataLoaded": isDataLoaded,
"ensureData": ensureData,
"reloadData": reloadData,
"setSort": setSort,
"setSearch": setSearch,
// events
"onDataLoading": onDataLoading,
"onDataLoaded": onDataLoaded
};
}
// Slick.Data.RemoteModel
$.extend(true, window, { Slick: { Data: { RemoteModel: RemoteModel }}});
})(jQuery);