用flexigrid实现分页显示 一

基本思路：

1. flexigird只在页面端显示数据，仅此而已

2. JavaScript业务代码负责调用REST API获得数据，然后操纵flexigrid显示数据。

特别是负责操控page bar，也就是flexigrid表格下方的哪个页面导航条进行中/英文支持，每个按钮的点击事件等。

3. REST API无状态，因此通过接收一些参数来计算返回的数据：

a. 查询条件 //根据不同的业务有所变化

b. pageSize //每页记录数目

c. pageIndex //期望返回的页面编号

返回的结果包括了：

a. 某页数据的JSON格式表示

b. 查询条件

c. 最大记录数

d. 最大页面数

先看个最后完成的效果图：

下面分步骤简述：

1. REST API的实现

REST API由于不记录状态，每次都是通过参数来得知要获取什么页面的数据。这个算法很多，有基于数据库自己提供的功能的，有纯粹在内存中计算的，我用的是先查询符合条件的记录总数，再分页，然后读取指定页的记录。

这到不是重点，关键是返回的数据格式JSON不按照flexigrid的要求，而是根据业务要求生成。之后页面端会有JavaScript代码将其转换成flexigrid格式。REST API返回的格式举例如下面的结果：

{"sign_page":{"max_sign_count":50,"page_index":1,"group_id":"","max_page_count":4,"signs":{"displays":[{"index":"0","value":{"id":"51fe01dbe4b0f241088d3b4e","userId":"4ee175ff82bc6273d0d4672f","address":"000000000001","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"1","value":{"id":"51fe01dbe4b0f241088d3b4f","userId":"4ee175ff82bc6273d0d4672f","address":"000000000002","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"2","value":{"id":"51fe01dbe4b0f241088d3b50","userId":"4ee175ff82bc6273d0d4672f","address":"000000000003","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"3","value":{"id":"51fe01dbe4b0f241088d3b51","userId":"4ee175ff82bc6273d0d4672f","address":"000000000004","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"4","value":{"id":"51fe01dbe4b0f241088d3b52","userId":"4ee175ff82bc6273d0d4672f","address":"000000000005","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"5","value":{"id":"51fe01dbe4b0f241088d3b53","userId":"4ee175ff82bc6273d0d4672f","address":"000000000006","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"6","value":{"id":"51fe01dbe4b0f241088d3b54","userId":"4ee175ff82bc6273d0d4672f","address":"000000000007","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"7","value":{"id":"51fe01dbe4b0f241088d3b55","userId":"4ee175ff82bc6273d0d4672f","address":"000000000008","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"8","value":{"id":"51fe01dbe4b0f241088d3b56","userId":"4ee175ff82bc6273d0d4672f","address":"000000000009","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"9","value":{"id":"51fe01dbe4b0f241088d3b57","userId":"4ee175ff82bc6273d0d4672f","address":"000000000010","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"10","value":{"id":"51fe01dbe4b0f241088d3b58","userId":"4ee175ff82bc6273d0d4672f","address":"000000000011","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"11","value":{"id":"51fe01dbe4b0f241088d3b59","userId":"4ee175ff82bc6273d0d4672f","address":"000000000012","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"12","value":{"id":"51fe01dbe4b0f241088d3b5a","userId":"4ee175ff82bc6273d0d4672f","address":"000000000013","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"13","value":{"id":"51fe01dbe4b0f241088d3b5b","userId":"4ee175ff82bc6273d0d4672f","address":"000000000014","groupName":"ok67","location":"function test","description":"","status":"offline"}},{"index":"14","value":{"id":"51fe01dbe4b0f241088d3b5c","userId":"4ee175ff82bc6273d0d4672f","address":"000000000015","groupName":"ok67","location":"function test","description":"","status":"offline"}}]}}}

2. JavaScript的实现

这是最重要的部分，必须完成JSON格式转换和page bar的操纵，比如事件绑定和处理等。为此，我实现了一个signTable.js，这是一个AMD模块。有了它，JavaScript就可以配置flexigrid，添加数据，并且支持分页。先看如何使用它。

    this.table.configSigns("myDisplays", this.locale, "multiple", this.ajaxUtility, this.artDialog);...    this.table.fillInSigns("myDisplays", this.locale, window.userDisplays.sign_page, this.onSelectDisplay, this);

this.table就是signTable对象。就提供了两个方法，configSigns方法配置了flexigrid的列等基本信息，并且支持多选或者单选模式。后面两个参数ajaxUtility和artDialog是另外的模块用来实现ajax调用和对话框的显示。下面是该函数的实现：

// config grid's basic structures, columents and events// tableId is the id of HTML table tag// locale is en or cn// selectMod single, multipleconfigSigns: function(tableId, locale, selectMod, ajaxUtility, artDialog) {    var id, description, location, status, page, innerHtml;    this.ajaxUtility = ajaxUtility;    this.artDialog = artDialog;    this.locale = locale;    if (locale === "en") {id = "ID";description = "Description";location = "Location";status = "Status";    } else if (locale === "cn") {id = "ID";description = "描述";location = "位置";status = "状态";    }    this.selectMod = selectMod;        $("#" + tableId).flexigrid({dataType: 'json',width: 630,height: 260,colModel : [    {display: '', name: 'id', width: 20, sortable: true, align: 'left'},    {display: id, name: 'address', width: 150, sortable: true, align: 'left'},    {display: description, name: 'description', width: 190, sortable: true, align: 'left'},    {display: location, name: 'location', width: 130, sortable: true, align: 'left'},    {display: status, name: 'status', width: 60, sortable: true, align: 'left'}],usepager: true    });},

下面是fillInSigns函数的实现，主要负责填充数据。

// tableId the id of HTML table tag// locale en or cn// value the data for filling in table// onSelect the event function for hanlding row selection// ob this for callback functionfillInSigns: function(tableId, locale, signPage, onSelect, ob) {    this.signPage = signPage;    $("#" + tableId).flexAddData(this.convert(locale, signPage));    $("#" + tableId +" tbody tr td div input").on("click", ob, onSelect);    this.updatePagebar();}

由于我的代码是从以前做的系统演化而来，所以signTable不是个通用的分页功能解决方案。仅在这里提供一个解决思路和完整的可参考代码，读者请自己根据情况修改吧。或许什么时候有时间，做成一个通用的flexigrid扩展也不一定。下面是signTable.js的全部内容：

// provides some common functions on top of flexigrid for simplifying web front-end development// If some web page use one same grid, add it here, they can resuse these codesdefine("signTable", ["jquery", "flexigrid", "flexigrid.pack"], function ($) {    'use strict';    return {// config grid's basic structures, columents and events// tableId is the id of HTML table tag// locale is en or cn// selectMod single, multipleconfigSigns: function(tableId, locale, selectMod, ajaxUtility, artDialog) {    var id, description, location, status, page, innerHtml;    this.ajaxUtility = ajaxUtility;    this.artDialog = artDialog;    this.locale = locale;    if (locale === "en") {id = "ID";description = "Description";location = "Location";status = "Status";    } else if (locale === "cn") {id = "ID";description = "描述";location = "位置";status = "状态";    }    this.selectMod = selectMod;        $("#" + tableId).flexigrid({dataType: 'json',width: 630,height: 260,colModel : [    {display: '', name: 'id', width: 20, sortable: true, align: 'left'},    {display: id, name: 'address', width: 150, sortable: true, align: 'left'},    {display: description, name: 'description', width: 190, sortable: true, align: 'left'},    {display: location, name: 'location', width: 130, sortable: true, align: 'left'},    {display: status, name: 'status', width: 60, sortable: true, align: 'left'}],usepager: true    });},getStatus: function (status) {    if (status === "online") {if (this.locale === "cn") {    return "在线";} else {    return "Online";}    }    if (status === "offline") {if (this.locale === "cn") {    return "离线";} else {    return "Offline";}    }    return status;},buildCell: function (line) {    var template;    if (this.selectMod == "multiple") {template = "{\"cell\":[\"<input id='{0}' class='row_class' type='checkbox' value='{0}'/>\",\"{1}\",\"{2}\",\"{3}\",\"{4}\"]}";return jQuery.validator.format(template, line.id, line.address, line.description, line.location,  this.getStatus(line.status));    } else {template = "{\"cell\":[\"<input id='{0}' class='row_class' name='single' type='radio' value='{0}'/>\",\"{1}\",\"{2}\",\"{3}\",\"{4}\"]}";return jQuery.validator.format(template, line.id, line.address, line.description, line.location,  this.getStatus(line.status));    }},convert : function (locale, signPage) {    var ds, d, i, str, s1, s2;    ds = signPage.signs.displays;    this.length = ds.length;    d = "{\"page\": 1,\"total\": 40,\"rows\":[";    for (i = 0; i < this.length; (i += 1)) {str = this.buildCell(ds[i].value);d += str;if (i !== (this.length - 1)) {    d += ",";}    }    d += "]}";    return jQuery.parseJSON(d);},afterLoadPageSigns: function (ob, data) {    if (data.status === 0) {ob.fillInSigns("myDisplays", ob.locale, JSON.parse(data.value).sign_page, ob.onSelectDisplay, ob);    } else {if (ob.locale === "cn") {    ob.artDialog.error('设备查询失败');} else {    ob.artDialog.error('Load signs failed.');}    }},// for inner reusesearch: function(pageIndex) {    var pageSize = $("select[name=rp]").val(), data;    data = {'groupId': this.signPage.group_id,'pageSize': pageSize,'pageIndex': pageIndex,'column': "address",'ascending': 1    };    this.ajaxUtility.post('pageSigns', false, data, this.afterLoadPageSigns, null, this);},onNext: function (event) {    var ob = event.data;    ob.search(ob.signPage.page_index + 1);},onPrev: function (event) {    var ob = event.data;    ob.search(ob.signPage.page_index - 1);},onLast: function (event) {    var ob = event.data;    ob.search(ob.signPage.max_page_count);},onFirst: function (event) {    var ob = event.data;    ob.search(1);},onReload: function (event) {    var pageIndex, ob = event.data;    pageIndex = $("#pageIndexInput").val();    if (pageIndex !== "") {ob.search(parseInt(pageIndex,10));     }},onChangePageSize: function (event) {    var ob = event.data;    ob.search(ob.signPage.page_index);    },/*onChangePageIndex: function (event) {    var ob, pageIndex;    ob = event.data;    pageIndex = $(this).val();    if (pageIndex !== "") {ob.search(parseInt(pageIndex,10));     }},*/// fill in Chinese or English words according to this.locale// fill in page number according to the total pages and current page index// enable/disable buttons in page barupdatePagebar: function() {    var innerHtml, t1, i, j, pageSize = 15;    if (this.locale === "cn") {t1 = "显示 {0} 到 {1}, 总数: {2} 设备";    } else {t1 = "from {0} to {1}, total: {2} signs";    }    i = pageSize * (this.signPage.page_index - 1) + 1;    j = i + pageSize - 1;    innerHtml = jQuery.validator.format(t1, i, j, this.signPage.max_sign_count);    $($(".pDiv2").children()[10]).children(0).html(innerHtml);    if (this.locale === "cn") {t1 = "页面 <input id=\"pageIndexInput\" type=\"number\" min=\"1\" style=\"width:30px;\" value=\"{0}\"> 到 <span>{1}</span>";    } else {t1 = "Page <input id=\"pageIndexInput\" type=\"number\" min=\"1\" style=\"width:30px;\" value=\"{0}\"> to <span>{1}</span>";    }    innerHtml = jQuery.validator.format(t1, this.signPage.page_index, this.signPage.max_page_count);    $(".pcontrol").html(innerHtml);    if (this.signPage.page_index === 1) {if (this.signPage.max_page_count === 1) {    $(".pPrev").removeClass("pButton");    $(".pFirst").removeClass("pButton");    $(".pNext").removeClass("pButton");    $(".pLast").removeClass("pButton");} else {    $(".pPrev").removeClass("pButton");    $(".pFirst").removeClass("pButton");    $(".pNext").addClass("pButton");    $(".pLast").addClass("pButton");}    } else {if (this.signPage.page_index === this.signPage.max_page_count) {    $(".pNext").removeClass("pButton");    $(".pLast").removeClass("pButton");    $(".pPrev").addClass("pButton");    $(".pFirst").addClass("pButton");} else {    $(".pNext").addClass("pButton");    $(".pLast").addClass("pButton");    $(".pPrev").addClass("pButton");    $(".pFirst").addClass("pButton");    }    }        if (!this.hasPageBarEvents) {$(".pNext").on("click", this, this.onNext);$(".pFirst").on("click", this, this.onFirst);$(".pPrev").on("click", this, this.onPrev);$(".pLast").on("click", this, this.onLast);$(".pReload").on("click", this, this.onReload);$("select[name=rp]").on("change", this, this.onChangePageSize);// $("#pageIndexInput").on("change", this, this.onChangePageIndex);this.hasPageBarEvents = true;    }},getSelectedNum: function() {    var n = 0;    $('.row_class').each(function () {    if ($(this).is(':checked')) {n += 1;    }}    );        return n;},// tableId the id of HTML table tag// locale en or cn// value the data for filling in table// onSelect the event function for hanlding row selection// ob this for callback functionfillInSigns: function(tableId, locale, signPage, onSelect, ob) {    this.signPage = signPage;    $("#" + tableId).flexAddData(this.convert(locale, signPage));    $("#" + tableId +" tbody tr td div input").on("click", ob, onSelect);    this.updatePagebar();}    };});