javascript 尝试扩展 ExtJs ComboBox 时出错 - “无法读取 null 的属性 'dom'”？
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Error trying to extend ExtJs ComboBox - "Cannot read property 'dom' of null"?
提问by shane87
I'm using ExtJs4 and I'm trying to extend the Ext.form.field.ComboBoxlike below:
我正在使用 ExtJs4，我正在尝试扩展Ext.form.field.ComboBox如下：
Ext.define('GenericCombo', {
extend: 'Ext.form.field.ComboBox',
alias: 'widget.genericcombo',
//the constructor
constructor: function(config) {
var store = new Ext.data.JsonStore({
fields: ['Key', 'Value'],
data : config.combodata || []
});//new Ext.data.Store
Ext.apply(this, config, {
store: store,
displayField: 'Value',
valueField: 'Key',
queryMode: 'local',
emptyText:'Select a value...'
});
this.callParent([this]);
}//end constructor
});//end Ext.define
The data for the store i.e. config.combodatais returned in JSON format like below:
商店 ie 的数据以config.combodataJSON 格式返回，如下所示：
"combodata":[
{"Key":"","Value":"<None>"},
{"Key":"!#","Value":"Dr"},
{"Key":"!$","Value":"Miss"}
]
However I get an error on line 61312of ext-all-debug.
(inside the renderActiveError method).
但是我在61312ext-all-debug线上得到一个错误。
（在 renderActiveError 方法中）。
Error: Uncaught TypeError: Cannot read property 'dom' of null
错误： Uncaught TypeError: Cannot read property 'dom' of null
Line 61312 :
第 61312 行：
me.errorEl.dom.innerHTML = activeError;
Am I missing something obvious here?
我在这里遗漏了一些明显的东西吗？
EDIT: Adding some code where I instantiate it:
I actually instantiate the combobox dynamically i.e. The server returns some extjs code dynamically in JSON format like below:
编辑：在我实例化它的地方添加一些代码：
我实际上动态实例化组合框，即服务器以JSON格式动态返回一些extjs代码，如下所示：
{
"anchor":"50%",
"autoScroll":false,
"border":false,
"combodata":[
{"Key":"","Value":"<None>"},
{"Key":"!#","Value":"Dr"}
],
"fieldLabel":"Title",
"name":"3820",
"value":"!)",
"xtype":"genericcombo"
}
However When i try to hardcode it i get the same error. Hardcoded example:
但是，当我尝试对其进行硬编码时，我得到了同样的错误。硬编码示例：
xtype: 'form',
title: 'A Form',
items:[{
xtype: 'genericcombo',
fieldLabel: 'Test',
combodata: [{Key: 'one', Value: 'two'}]
}]
回答by shane87
I was calling
我在打电话
this.callParent([this]); //Which is wrong and caused my error.
The correct way is to call
正确的方法是调用
this.callParent([arguments]);
回答by JamesHalsall
Try this... move everything in your constructorto the initComponentmethod. Then in your constructoryou need to call the parent's constructor...
在尝试......举动一切你constructor的initComponent方法。然后在constructor你需要打电话给父母的constructor...
constructor : function(config) {
GenericCombo.superclass.constructor.apply(this,new Array(config);
}
I would also consider namespacing your component... something like Ext.ux.GenericCombowould be better suited.
我也会考虑给你的组件命名空间......类似的东西Ext.ux.GenericCombo会更适合。
