如何从封闭小部件以编程方式打开继承自 dijit/_HasDropDown 的 dojo 小部件？

Question

我有以下自定义 dojo 小部件：

<div class="${baseClass}">
    <div data-dojo-type="dijit/TitlePane" data-dojo-props="title:'${prefixTitle}', open:false" id="titleNodePane">
        <div id="container"
        class="${baseClass}Container"
        data-dojo-attach-point="containerNode"></div>
    </div>
</div>

使用此代码：

/**
 * Javascript for ExpandableSearchComponent
 */
define([ "dojo/_base/declare", "dijit/_WidgetBase", "dijit/_TemplatedMixin",
        "dojo/text!./templates/ExpandableSearchComponent.html",
        "dijit/TitlePane", "dijit/_WidgetsInTemplateMixin", "dijit/registry",
        "dojo/on", "dojo/aspect", "dojo/_base/lang" ], function(declare,
        _WidgetBase, _TemplatedMixin, template, TitlePane,
        _WidgetsInTemplateMixin, registry, on, aspect, lang) {

    return declare([ _WidgetBase, _TemplatedMixin, _WidgetsInTemplateMixin ], {
        templateString : template,
        prefixTitle : "",
        containedWidgetId : "",
        that : this,

        startup : function() {
            this.inherited(arguments);
            var containedWidget = registry.byId(this.containedWidgetId);
            var titlePane = registry.byId("titleNodePane");
            this.own(on(titlePane, "Show", function() {

                containedWidget.openDropDown();

            }.bind(containedWidget)));
            //Other logic

        }
    });

});

声明如下：

<div data-dojo-type="js/widgets/ExpandableSearchComponent"                                  
    data-dojo-props="prefixTitle: 'Name: ', containedWidgetId: 'machineSearchView.name'">   
<!-- Other elements including the machineNameStore-->                                                          
    <div data-dojo-type="dijit/form/ComboBox"                                               
        data-dojo-props="store:machineNameStore, searchAttr:'name', value:'${MachineName}'" 
        name="machineSearchView.name" id="machineSearchView.name"></div>                    
</div>

它的工作几乎完美，除了一件事：on(titlePane, "Show", function(){})。这旨在打开包含扩展 _HasDropDown 的小部件的下拉列表。我在 _HasDropDown 的第 139 行收到错误 Uncaught TypeError: Cannot read property 'domNode' of null。显然，this.dropDown 在 TitlePane 完全展开之前不会被设置，这会破坏 openDropDown()。

有办法解决这个问题吗？

Answer 1

_HasDropDown mixin 也有一个 loadAndOpenDropDown() 函数，如果下拉菜单不存在则创建它，然后打开它。

如何从封闭小部件以编程方式打开继承自 dijit/_HasDropDown 的 dojo 小部件？

How to open dojo widget that inherits from dijit/_HasDropDown programmatically from enclosing widget?

javascript

dojo