使用對節點JS卡桑德拉節點驅動程序(KOA JS,馬爾科JS):分頁 問題
由於不存在的跳過功能,我們需要解決。下面是節點應用程序的手動分頁的實現,以便任何人都可以得到想法。
- 簡單的用戶列表的代碼
- 下一個和前一頁的狀態之間進行切換
- 容易複製
有兩種解決方案,我要去在此聲明,但只給了代碼下面的解決方案1,
解決方案1:維護頁面狀態next
和previous
記錄(維護堆棧或任何數據結構爲ST FIT)
解決方案2:循環通過與限制的所有記錄和保存所有可能的頁面的狀態變量和相對生成頁面他們pageStates
使用模型這個註釋的代碼,我們可以得到所有國家
頁
//for the next flow
//if (result.nextPage) {
// Retrieve the following pages:
// the same row handler from above will be used
// result.nextPage();
//}
路由器功能
var userModel = require('/models/users');
public.get('/users', users);
public.post('/users', filterUsers);
var users = function*() {//get request
var data = {};
var pageState = { "next": "", "previous": "" };
try {
var userCount = yield userModel.Count();//count all users with basic count query
var currentPage = 1;
var pager = yield generatePaging(currentPage, userCount, pagingMaxLimit);
var userList = yield userModel.List(pager);
data.pageNumber = currentPage;
data.TotalPages = pager.TotalPages;
console.log('--------------what now--------------');
data.pageState_next = userList.pageStates.next;
data.pageState_previous = userList.pageStates.previous;
console.log("next ", data.pageState_next);
console.log("previous ", data.pageState_previous);
data.previousStates = null;
data.isPrevious = false;
if ((userCount/pagingMaxLimit) > 1) {
data.isNext = true;
}
data.userList = userList;
data.totalRecords = userCount;
console.log('--------------------userList--------------------', data.userList);
//pass to html template
}
catch (e) {
console.log("err ", e);
log.info("userList error : ", e);
}
this.body = this.stream('./views/userList.marko', data);
this.type = 'text/html';
};
//post filter and get list
var filterUsers = function*() {
console.log("<------------------Form Post Started----------------->");
var data = {};
var totalCount;
data.isPrevious = true;
data.isNext = true;
var form = this.request.body;
console.log("----------------formdata--------------------", form);
var currentPage = parseInt(form.hdpagenumber);//page number hidden in html
console.log("-------before current page------", currentPage);
var pageState = null;
try {
var statesArray = [];
if (form.hdallpageStates && form.hdallpageStates !== '') {
statesArray = form.hdallpageStates.split(',');
}
console.log(statesArray);
//develop stack to track paging states
if (form.hdpagestateRequest === 'next') {
console.log('--------------------------next---------------------');
currentPage = currentPage + 1;
statesArray.push(form.hdpageState_next);
pageState = form.hdpageState_next;
}
else if (form.hdpagestateRequest === 'previous') {
console.log('--------------------------pre---------------------');
currentPage = currentPage - 1;
var p_st = statesArray.length - 2;//second last index
console.log('this index of array to be removed ', p_st);
pageState = statesArray[p_st];
statesArray.splice(p_st, 1);
//pageState = statesArray.pop();
}
else if (form.hdispaging === 'false') {
currentPage = 1;
pageState = null;
statesArray = [];
}
data.previousStates = statesArray;
console.log("paging true");
totalCount = yield userModel.Count();
var pager = yield generatePaging(form.hdpagenumber, totalCount, pagingMaxLimit);
data.pageNumber = currentPage;
data.TotalPages = pager.TotalPages;
//filter function - not yet constructed
var searchUsers = yield userModel.searchList(pager, pageState);
data.usersList = searchUsers;
if (searchUsers.pageStates) {
data.pageStates = searchUsers.pageStates;
data.next = searchUsers.nextPage;
data.pageState_next = searchUsers.pageStates.next;
data.pageState_previous = searchUsers.pageStates.previous;
//show previous and next buttons accordingly
if (currentPage == 1 && pager.TotalPages > 1) {
data.isPrevious = false;
data.isNext = true;
}
else if (currentPage == 1 && pager.TotalPages <= 1) {
data.isPrevious = false;
data.isNext = false;
}
else if (currentPage >= pager.TotalPages) {
data.isPrevious = true;
data.isNext = false;
}
else {
data.isPrevious = true;
data.isNext = true;
}
}
else {
data.isPrevious = false;
data.isNext = false;
}
console.log("response ", searchUsers);
data.totalRecords = totalCount;
//pass to html template
}
catch (e) {
console.log("err ", e);
log.info("user list error : ", e);
}
console.log("<------------------Form Post Ended----------------->");
this.body = this.stream('./views/userList.marko', data);
this.type = 'text/html';
};
//Paging function
var generatePaging = function* (currentpage, count, pageSizeTemp) {
var paging = new Object();
var pagesize = pageSizeTemp;
var totalPages = 0;
var pageNo = currentpage == null ? null : currentpage;
var skip = pageNo == null ? 0 : parseInt(pageNo - 1) * pagesize;
var pageNumber = pageNo != null ? pageNo : 1;
totalPages = pagesize == null ? 0 : Math.ceil(count/pagesize);
paging.skip = skip;
paging.limit = pagesize;
paging.pageNumber = pageNumber;
paging.TotalPages = totalPages;
return paging;
};
個型號功能
var clientdb = require('../utils/cassandradb')();
var Users = function (options) {
//this.init();
_.assign(this, options);
};
Users.List = function* (limit) {//first time
var myresult; var res = [];
res.pageStates = { "next": "", "previous": "" };
const options = { prepare: true, fetchSize: limit };
console.log('----------did i appeared first?-----------');
yield new Promise(function (resolve, reject) {
clientdb.eachRow('SELECT * FROM users_lookup_history', [], options, function (n, row) {
console.log('----paging----rows');
res.push(row);
}, function (err, result) {
if (err) {
console.log("error ", err);
}
else {
res.pageStates.next = result.pageState;
res.nextPage = result.nextPage;//next page function
}
resolve(result);
});
}).catch(function (e) {
console.log("error ", e);
}); //promise ends
console.log('page state ', res.pageStates);
return res;
};
Users.searchList = function* (pager, pageState) {//paging filtering
console.log("|------------Query Started-------------|");
console.log("pageState if any ", pageState);
var res = [], myresult;
res.pageStates = { "next": "" };
var query = "SELECT * FROM users_lookup_history ";
var params = [];
console.log('current pageState ', pageState);
const options = { pageState: pageState, prepare: true, fetchSize: pager.limit };
console.log('----------------did i appeared first?------------------');
yield new Promise(function (resolve, reject) {
clientdb.eachRow(query, [], options, function (n, row) {
console.log('----Users paging----rows');
res.push(row);
}, function (err, result) {
if (err) {
console.log("error ", err);
}
else {
res.pageStates.next = result.pageState;
res.nextPage = result.nextPage;
}
//for the next flow
//if (result.nextPage) {
// Retrieve the following pages:
// the same row handler from above will be used
// result.nextPage();
//}
resolve(result);
});
}).catch(function (e) {
console.log("error ", e);
info.log('something');
}); //promise ends
console.log('page state ', pageState);
console.log("|------------Query Ended-------------|");
return res;
};
HTML端
<div class="box-footer clearfix">
<ul class="pagination pagination-sm no-margin pull-left">
<if test="data.isPrevious == true">
<li><a class='submitform_previous' href="">Previous</a></li>
</if>
<if test="data.isNext == true">
<li><a class="submitform_next" href="">Next</a></li>
</if>
</ul>
<ul class="pagination pagination-sm no-margin pull-right">
<li>Total Records : $data.totalRecords</li>
<li> | Total Pages : $data.TotalPages</li>
<li> | Current Page : $data.pageNumber</li>
</ul>
</div>
我不是非常符合節點js和卡桑德拉分貝經歷,這個解決方案一定能得到改善。解決方案1是工作示例代碼,以分頁的想法開始。歡呼聲
DSE已經支持深度尋呼了嗎?據我所知,這個特性是在Solr 4.7中引入的,但是DSE 4.5(最新版本)仍在使用Solr 4.6。將嘗試這種艱難 – 2014-11-06 06:45:24
4.7 - 深度分頁有一個改進 - 遊標功能https://issues.apache.org/jira/browse/SOLR-5463但分頁在4.6 – phact 2014-11-06 06:49:41
也檢查我們的示例代碼在github有一個很好的分頁示例https://github.com/DataStaxCodeSamples/datastax-paging-demo – phact 2014-11-06 15:50:09