带有来自 url（json 数据）的存储的 dojo dgrid 重新加载/刷新按钮

Question

首先，我使用的是 dojo 1.1.0 和 dgrid 0.4.0。我正在创建一个带有一些 dgrids 的页面。一个网格特别需要从 url 加载 JSON 数据并显示它。它目前可以很好地使用 RequestMemory 存储。然而，这是一个“记忆”存储。虽然这对其他一些人来说可能是微不足道的，但我需要找到一种方法来加载数据，因为它现在正在完成，然后在屏幕上添加一个刷新按钮，调用必要的函数/方法来从 url 重新加载数据和重新填充 dgrid。

JSON 数据来自格式如下的 url：

[{"id":1,"name":"trans1","username":"trans1","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":true},{"id":2,"name":"trans2","username":"trans2","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":true},{"id":3,"name":"trans3","username":"trans3","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false},{"id":4,"name":"trans4","username":"trans4","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false},{"id":5,"name":"trans5","username":"trans5","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false},{"id":6,"name":"trans6","username":"trans6","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false}]

您将在下面看到的 Require 实际上包含的不仅仅是这个网格......因此还有所有额外内容。

我不需要更新本地商店，也不想监视 url 的变化。我只是希望能够根据需要从 url 重新加载数据。

这是我目前用于初始加载网格（工作）的代码和我需要开始工作的刷新按钮。

require([ 'dojo/store/Observable' ,'dijit/Dialog', 'dijit/form/Select', 'dijit/form/MultiSelect', 'dijit/form/TextBox', 'dijit/layout/TabContainer', 'dijit/layout/ContentPane','dojo/request', 'dojo/request/xhr', 'dijit/form/ToggleButton', 'dijit/form/Button', 'dojo/parser', 'dojo/_base/declare', 'dgrid/Grid', 'dgrid/Selection', 'dgrid/Editor', 'dgrid/extensions/ColumnHider', 'dgrid/extensions/Pagination', 'dstore/RequestMemory', 'dijit/form/Select', 'dijit/registry','dojox/data/XmlStore', 'dojo/domReady!'], function (Observable, Dialog, Select, MultiSelect, TextBox, TabContainer, ContentPane, request, xhr, ToggleButton, Button, parser, declare, Grid, Selection, Editor, ColumnHider, Pagination, RequestMemory, Select, registry, XmlStore) {


//workers dgrid
    var workersStore = new RequestMemory({ target: '/autoAssign/getWorkers.aa?TASKTYPE=transport&INACTIVE=FALSE' });        
    var workerGrid = new (declare([ Grid, Selection, Pagination, Editor, ColumnHider ]))({
        collection: workersStore,
        className: 'dgrid-autoheight',
        id: 'workerGrid',
        rowsPerPage: 6,
        columns: {
            name: 'Name',
            username: {
                label: 'username',
                hidden: true
            },
            status: 'Status',
            assignedNum: 'Assigned',
            completedNum: 'Completed',
            avgTime: 'Average',
            aaOn: {
		      label: 'Auto Assign',
		      editor: 'checkbox',
                  }
        }
    }, 'gridNode');
    workerGrid.on("dgrid-datachange",function(evt) {
       var row = workerGrid.row(evt); 
       if (evt.cell.column.id == 'aaOn') {
           var promise = request('/autoAssign/setUserAaStatus.aa?USERNAME='+row.data.username+'&TASKTYPE=transport&STATUS='+evt.value);
       }
    });
    workerGrid.startup();


//Add refresh Button
      var addRefreshButton = new Button({
        label: "Refresh",
        style: 'float:right;',
        onClick: function(){
           var promise = workersStore.fetch();
           var result = promise.then(function(data){
               workerGrid.set("collection", workersStore);
               workerGrid.refresh();
               alert("refresh pushed");
           });
        }
    }, "refresh").startup(); 


}

[{"id":1,"name":"trans1","username":"trans1","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":true},{"id":2,"name":"trans2","username":"trans2","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":true},{"id":3,"name":"trans3","username":"trans3","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false},{"id":4,"name":"trans4","username":"trans4","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false},{"id":5,"name":"trans5","username":"trans5","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false},{"id":6,"name":"trans6","username":"trans6","status":"Available","inactive":"no","checkedout":"false","details":"","assignedNum":"0","completedNum":"0","avgTime":"00:00","aaOn":false}]

任何帮助将不胜感激。我以前使用 Dojo 的旧数据网格执行此操作，但似乎无法理解我在这里缺少的内容。

Answer 1

从技术上讲，为了做你想做的事，你做需要以某种方式更新本地商店。 dstore/RequestMemory 本质上是dstore/Request 和dstore/Cache 的组合，其中单个fetch 请求立即执行，然后缓存存储字段所有未来的提取操作。为了强制商店从服务器刷新，你基本上需要告诉商店它的缓存不再有效，然后重新向服务器请求所有物品。这相当于：

workersStore.invalidate(); // Invalidate the cache
workersStore.fetch(); // Perform a new request for all items
workerGrid.refresh();

一旦执行了fetch，Cache 存储就会明白它可以从其内存存储中提取所有请求。

(fetch 调用很重要 - 如果您不调用上面的 fetch，您的网格可能无法按预期工作。dgrid 的 OnDemandGrid 和 Pagination 模块使用 fetchRange 执行范围查询，除非 Cache 知道它拥有商店的所有数据，它只会让这些数据通过原始商店，在这种情况下是请求，它将尝试访问服务器 - 除非您的服务可能不具备处理范围查询的能力，所以它会每次只返回整个数据集。）

诚然，我认为这比使用 RequestMemory 的人需要知道的信息还要多，所以我可能会提交有关刷新和/或更新 target 的某种 API 的问题。上面的 3 行代码虽然是 TL;DR。