Helper for client side customized pagination
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/424499/1723642/Brazen%20Paginator.js
// ==UserScript==
// @name Brazen Paginator
// @namespace brazenvoid
// @version 3.0.0
// @author brazenvoid
// @license GPL-3.0-only
// @description Helper for client side customized pagination
// ==/UserScript==
class BrazenPaginator
{
/**
* @typedef {{itemListSelector: JQuery.Selector, itemSelectors?: JQuery.Selector, lastPageUrl: string,
* onGetPageNoFromUrl: PaginatorGetPageNoFromUrlHandler, onGetPageUrlFromPageNo: PaginatorGetPageUrlFromPageNoHandler,
* onGetPaginationElementForPageNo: PaginatorGetPaginationElementForPageNoHandler, paginationWrapper: JQuery}} PaginatorConfiguration
*/
/**
* @callback PaginatorAfterPaginationEventHandler
* @param {BrazenPaginator} paginator
*/
/**
* @callback PaginatorGetPageNoFromUrlHandler
* @param {string} pageUrl
* @param {BrazenPaginator} paginator
*/
/**
* @callback PaginatorGetPageUrlFromPageNoHandler
* @param {number} pageNo
* @param {BrazenPaginator} paginator
*/
/**
* @callback PaginatorGetPaginationElementForPageNoHandler
* @param {number} pageNo
* @param {BrazenPaginator} paginator
*/
/**
* @type {PaginatorConfiguration}
* @private
*/
_config
/**
* @type {number}
* @private
*/
_currentPageNo = 0
/**
* @type {number}
* @private
*/
_lastPageNo = 0
/**
* @type {PaginatorAfterPaginationEventHandler}
* @private
*/
_onAfterPagination = null
/**
* @type {boolean}
* @private
*/
_pageConcatenated = false
/**
* @type {number}
* @private
*/
_paginatedPageNo = 0
/**
* @type {JQuery}
* @private
*/
_targetElement = null
/**
* @param {PaginatorConfiguration} configuration
*/
constructor(configuration)
{
this._config = configuration
}
_conformUIToNewPaginatedState()
{
if (this._pageConcatenated) {
this._pageConcatenated = false
let currentPageElement = this.getPaginationElementForPageNo(this._currentPageNo)
let newSubsequentPageNo = this._paginatedPageNo + 1
let newSubsequentPageNoUrl = this.getPageUrlFromPageNo(newSubsequentPageNo)
// Mutate current page no element to show paginated page numbers
currentPageElement.text(this._currentPageNo + '-' + this._paginatedPageNo)
// Get next pages' pagination elements
let currentNextPageElements = currentPageElement.nextAll()
if (this._paginatedPageNo === this._lastPageNo) {
// Delete all pagination elements if last page is paginated
currentNextPageElements.remove()
} else {
// Determine whether the paginated page immediately precedes the last page
if (newSubsequentPageNo !== this._lastPageNo) {
// If not so, determine whether pagination element for the page following the paginated page exists
let newSubsequentPageElement = this.getPaginationElementForPageNo(newSubsequentPageNo)
if (!newSubsequentPageElement.length) {
// If it does not exist then try getting the old next page no element
let oldSubsequentPageElement = this.getPaginationElementForPageNo(this._currentPageNo + 1)
if (oldSubsequentPageElement.length) {
// If it does exist then mutate it for this purpose
oldSubsequentPageElement.attr('href', newSubsequentPageNoUrl).text(newSubsequentPageNo)
} else {
// If even that does not exist, then clone the less desirable alternative; the last page element and mutate it to this use
let lastPageElement = this.getPaginationElementForPageNo(this._lastPageNo)
lastPageElement.clone().insertAfter(currentPageElement).attr('href', newSubsequentPageNoUrl).text(newSubsequentPageNo)
}
}
// Remove any other pagination elements for already paginated pages
currentNextPageElements.each((index, element) => {
let paginationLink = $(element)
let paginationLinkUrl = paginationLink.attr('href')
if (paginationLinkUrl && this.getPageNoFromUrl(paginationLinkUrl) <= this._paginatedPageNo) {
paginationLink.remove()
}
})
}
}
Utilities.callEventHandler(this._onAfterPagination, [this])
}
}
/**
* @param {number} threshold
* @param {number} limit
* @private
*/
_loadAndParseNextPage(threshold, limit)
{
let lastPageHasNotBeenReached = this._paginatedPageNo < this._lastPageNo
let paginationLimitHasNotBeenMet = limit > 0 && (this._paginatedPageNo - this._currentPageNo) < limit
let compliantItemsAreLessThanTheThreshold =
this._targetElement.find(this._config.itemSelectors + ':not(.' + CLASS_NON_COMPLIANT_ITEM + ')').length < threshold
if (lastPageHasNotBeenReached && paginationLimitHasNotBeenMet && compliantItemsAreLessThanTheThreshold) {
this._sandbox.load(this.getPageUrlFromPageNo(++this._paginatedPageNo) + ' ' + this._config.itemListSelector, '', () => {
this._pageConcatenated = true
this._sandbox.find(this._config.itemSelectors).insertAfter(this._targetElement.find(this._config.itemSelectors + ':last'))
this._sandbox.empty()
})
} else {
this._conformUIToNewPaginatedState()
}
}
getCurrentPageNo()
{
return this._currentPageNo
}
getItemListSelector()
{
return this._config.itemListSelector
}
getLastPageNo()
{
return this._lastPageNo
}
/**
* @param {string} pageUrl
* @return {number}
*/
getPageNoFromUrl(pageUrl)
{
return this._config.onGetPageNoFromUrl(pageUrl, this)
}
/**
* @param {number} pageNo
* @return {string}
*/
getPageUrlFromPageNo(pageNo)
{
return this._config.onGetPageUrlFromPageNo(pageNo, this)
}
getPaginatedPageNo()
{
return this._paginatedPageNo
}
/**
* @param {number} pageNo
* @return {JQuery}
*/
getPaginationElementForPageNo(pageNo)
{
return this._config.onGetPaginationElementForPageNo(pageNo, this)
}
getPaginationWrapper()
{
return this._config.paginationWrapper
}
initialize()
{
this._currentPageNo = this.getPageNoFromUrl(window.location.href)
this._lastPageNo = this.getPageNoFromUrl(this._config.lastPageUrl)
this._paginatedPageNo = this._currentPageNo
this._sandbox = $('<div id="brazen-paginator-sandbox" hidden/>').appendTo('body')
this._targetElement = $(this._config.itemListSelector + ':first')
return this
}
/**
* @param {PaginatorAfterPaginationEventHandler} handler
* @return {this}
*/
onAfterPagination(handler)
{
this._onAfterPagination = handler
return this
}
run(threshold, limit)
{
if (this._config.paginationWrapper.length && threshold) {
this._loadAndParseNextPage(threshold, limit)
}
return this
}
}