/**
* This jQuery plugin displays pagination links inside the selected elements.
*
* This plugin needs at least jQuery 1.4.2
*
* @author Gabriel Birke (birke *at* d-scribe *dot* de)
* @version 2.2
* @param {int} maxentries Number of entries to paginate
* @param {Object} opts Several options (see README for documentation)
* @return {Object} jQuery Object
*/
(function ($) {
/**
* @class Class for calculating pagination values
*/
$.PaginationCalculator = function (maxentries, opts) {
this.maxentries = maxentries;
this.opts = opts;
}
$.extend($.PaginationCalculator.prototype, {
/**
* Calculate the maximum number of pages
* @method
* @returns {Number}
*/
numPages: function () {
return Math.ceil(this.maxentries / this.opts.items_per_page);
},
/**
* Calculate start and end point of pagination links depending on
* current_page and num_display_entries.
* @returns {Array}
*/
getInterval: function (current_page) {
var ne_half = Math.floor(this.opts.num_display_entries / 2);
var np = this.numPages();
var upper_limit = np - this.opts.num_display_entries;
var start = current_page > ne_half ? Math.max(Math.min(current_page - ne_half, upper_limit), 0) : 0;
var end = current_page > ne_half ? Math.min(current_page + ne_half + (this.opts.num_display_entries % 2), np) : Math.min(this.opts.num_display_entries, np);
return { start: start, end: end };
}
});
// Initialize jQuery object container for pagination renderers
$.PaginationRenderers = {}
/**
* @class Default renderer for rendering pagination links
*/
$.PaginationRenderers.defaultRenderer = function (maxentries, opts) {
this.maxentries = maxentries;
this.opts = opts;
this.pc = new $.PaginationCalculator(maxentries, opts);
}
$.extend($.PaginationRenderers.defaultRenderer.prototype, {
/**
* Helper function for generating a single link (or a span tag if it's the current page)
* @param {Number} page_id The page id for the new item
* @param {Number} current_page
* @param {Object} appendopts Options for the new item: text and classes
* @returns {jQuery} jQuery object containing the link
*/
createLink: function (page_id, current_page, appendopts) {
var lnk, np = this.pc.numPages();
page_id = page_id < 0 ? 0 : (page_id < np ? page_id : np - 1); // Normalize page id to sane value
appendopts = $.extend({ text: page_id + 1, classes: "" }, appendopts || {});
if (page_id == current_page) {
lnk = $("" + appendopts.text + "");
}
else {
lnk = $("" + appendopts.text + "")
.attr('href', this.opts.link_to.replace(/__id__/, page_id));
}
if (appendopts.classes) { lnk.addClass(appendopts.classes); }
lnk.data('page_id', page_id);
return lnk;
},
// Generate a range of numeric links
appendRange: function (container, current_page, start, end, opts) {
var i;
for (i = start; i < end; i++) {
this.createLink(i, current_page, opts).appendTo(container);
}
},
getLinks: function (current_page, eventHandler) {
var begin, end,
interval = this.pc.getInterval(current_page),
np = this.pc.numPages(),
fragment = $("");
// Generate "Previous"-Link
if (this.opts.prev_text && (current_page > 0 || this.opts.prev_show_always)) {
fragment.append(this.createLink(current_page - 1, current_page, { text: this.opts.prev_text, classes: "prev" }));
}
// Generate starting points
if (interval.start > 0 && this.opts.num_edge_entries > 0) {
end = Math.min(this.opts.num_edge_entries, interval.start);
this.appendRange(fragment, current_page, 0, end, { classes: 'sp' });
if (this.opts.num_edge_entries < interval.start && this.opts.ellipse_text) {
jQuery("" + this.opts.ellipse_text + "").appendTo(fragment);
}
}
// Generate interval links
this.appendRange(fragment, current_page, interval.start, interval.end);
// Generate ending points
if (interval.end < np && this.opts.num_edge_entries > 0) {
if (np - this.opts.num_edge_entries > interval.end && this.opts.ellipse_text) {
jQuery("" + this.opts.ellipse_text + "").appendTo(fragment);
}
begin = Math.max(np - this.opts.num_edge_entries, interval.end);
this.appendRange(fragment, current_page, begin, np, { classes: 'ep' });
}
// Generate "Next"-Link
if (this.opts.next_text && (current_page < np - 1 || this.opts.next_show_always)) {
fragment.append(this.createLink(current_page + 1, current_page, { text: this.opts.next_text, classes: "next" }));
}
$('a', fragment).click(eventHandler);
return fragment;
}
});
// Extend jQuery
$.fn.pagination = function (maxentries, opts) {
// Initialize options with default values
opts = jQuery.extend({
items_per_page: 10,
num_display_entries: 11,
current_page: 0,
num_edge_entries: 0,
link_to: "#",
prev_text: "Prev",
next_text: "Next",
ellipse_text: "...",
prev_show_always: true,
next_show_always: true,
renderer: "defaultRenderer",
load_first_page: false,
callback: function () { return false; }
}, opts || {});
var containers = this,
renderer, links, current_page;
/**
* This is the event handling function for the pagination links.
* @param {int} page_id The new page number
*/
function paginationClickHandler(evt) {
var links,
new_current_page = $(evt.target).data('page_id'),
continuePropagation = selectPage(new_current_page);
if (!continuePropagation) {
evt.stopPropagation();
}
return continuePropagation;
}
/**
* This is a utility function for the internal event handlers.
* It sets the new current page on the pagination container objects,
* generates a new HTMl fragment for the pagination links and calls
* the callback function.
*/
function selectPage(new_current_page) {
// update the link display of a all containers
containers.data('current_page', new_current_page);
links = renderer.getLinks(new_current_page, paginationClickHandler);
containers.empty();
links.appendTo(containers);
// call the callback and propagate the event if it does not return false
var continuePropagation = opts.callback(new_current_page, containers);
return continuePropagation;
}
// -----------------------------------
// Initialize containers
// -----------------------------------
current_page = opts.current_page;
containers.data('current_page', current_page);
// Create a sane value for maxentries and items_per_page
maxentries = (!maxentries || maxentries < 0) ? 1 : maxentries;
opts.items_per_page = (!opts.items_per_page || opts.items_per_page < 0) ? 1 : opts.items_per_page;
if (!$.PaginationRenderers[opts.renderer]) {
throw new ReferenceError("Pagination renderer '" + opts.renderer + "' was not found in jQuery.PaginationRenderers object.");
}
renderer = new $.PaginationRenderers[opts.renderer](maxentries, opts);
// Attach control events to the DOM elements
var pc = new $.PaginationCalculator(maxentries, opts);
var np = pc.numPages();
containers.bind('setPage', { numPages: np }, function (evt, page_id) {
if (page_id >= 0 && page_id < evt.data.numPages) {
selectPage(page_id); return false;
}
});
containers.bind('prevPage', function (evt) {
var current_page = $(this).data('current_page');
if (current_page > 0) {
selectPage(current_page - 1);
}
return false;
});
containers.bind('nextPage', { numPages: np }, function (evt) {
var current_page = $(this).data('current_page');
if (current_page < evt.data.numPages - 1) {
selectPage(current_page + 1);
}
return false;
});
// When all initialisation is done, draw the links
links = renderer.getLinks(current_page, paginationClickHandler);
containers.empty();
links.appendTo(containers);
// call callback function
if (opts.load_first_page) {
opts.callback(current_page, containers);
}
} // End of $.fn.pagination block
})(jQuery);
