分页不起作用，将JsonRest与EnhancedGrid一起使用 [英] Paging is not working, using JsonRest with EnhancedGrid

问题描述

我正在为IBM BusinessSpace创建小部件，我在分页时遇到了一些困难。
数据从数据库（使用restlet）成功返回并显示在网格中。导航也显示在网格下方（下一页，上一页，转到页面，页数等）。
例如，如果我有3页，每页5行，并且要导航到第二页，当我点击页码2时，数据重新加载（看起来像restlet再次被调用），然后第一个这一行也显示5行（第一页显示）。如果我选择任何其他导航选项（下一页，...），同样的事情发生。底线，每次点击都会从我的数据库中获得前5行。
如何解决这个问题的任何线索？

I'm creating widget for IBM BusinessSpace, and I'm having some difficulties with paging. Data are succesfully returned from database (using restlet) and displayed in a grid. Navigation is also displayed below the grid (next page, previous page, go to page, number of pages, etc). If I, for example, have 3 pages, 5 rows per page, and want to navigate to second page, when I click on the page number 2, data reloads (it seems like restlet is called again), and first 5 rows (displayed on the first page) are showed on this one too. If I choose any other navigation option (next page, ...), same thing happeneds. Bottom line, every click results in first 5 rows from my database. Any clue on how to resolve this issue?

以下是关于此的代码：

dojo.require("dojo.data.ObjectStore"); 
dojo.require("dojox.grid.enhanced.plugins.Pagination"); 
dojo.require("dojox.grid.EnhancedGrid"); 
dojo.require("dojo.store.JsonRest"); 


var restStore = new dojo.store.JsonRest({target:"https://localhost:9443/Application/hello"}); 

var dataStore = dojo.data.ObjectStore({objectStore: restStore}); 

dojo.ready(function(){ 

    var grid = new dojox.grid.EnhancedGrid({ 

        store: dataStore, <br>
        structure: [                   
            {name:"Value", field:"value", width: "auto"}, 
            {name:"RequestID", field:"requestId", width: "auto"}, 
            {name:"ID", field:"id", width: "auto"}, 
            {name:"Name", field:"name", width: "auto"} 
        ],         
        columnReordering: true, 
        clientSort: true, 
        rowSelector: '20px', 
        rowsPerPage: 5, 
        autoHeight: true, 
        plugins: {
            pagination: { 
                pageSizes: ["5", "10", "15", "All"], // page length menu options 
                description: true, // display the current position
                sizeSwitch: true, // display the page length menu
                pageStepper: true, // display the page navigation choices 
                gotoButton: true, // go to page button   
                position: "bottom" // position of the pagination bar  
            }
        } 
    }, "gridDiv");
    grid.startup(); 
});

推荐答案

在网格中使用jsonRest时，滚动没有显示的记录尚未加载，此时，jsonRest请求显示所需的数据，为了这个寻呼机按预期工作，在您的休息实现中，您必须使用dojo创建的头（范围：0-24） ，这个由dojo发送，所以你知道所需数据的偏移量和限制，对于响应，你必须返回一个头（Content-Range：items 0-24 / 66），这个数字告诉dojo从哪里到哪里它应该是显示和总记录的数量。

When using jsonRest in a grid, when you scroll the records not shown are not loaded yet, at this moment jsonRest makes a request for the data needed to show, for this pager to work as expected, in your rest implementation you have to consume a header that dojo creates (Range: 0-24), this one is sent by dojo so you know the offset and limit for the data needed, for the response, you have to return a header (Content-Range: items 0-24/66), the numbers tell dojo from where to where it should be showing and how much total record are.

这是php中的一个例子（假设db和响应是实际对象）：

This is an example in php (assuming that db and response are actual objects):

$range = $request->headers->get('Range');

preg_match_all ('/.*?(\d+).*?(\d+)/is', $range, $matches);

$limit = $matches[2][0];
$offset = $matches[1][0];

$sql = "SELECT SQL_CALC_FOUND_ROWS * FROM table LIMIT {$limit} OFFSET {$offset}";
$result = $db->execute($sql);

$sql2 = "SELECT FOUND_ROWS()";
$count = $db->execute($sql2);

$response->setContent($result);
$response->headers->set('Content-Range', "items $offset-$limit/{$count}");

在jsonRest 文档有一些信息。

In jsonRest documentation there is some information.

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