dojo声明正确的方式 [英] dojo declare correct way
问题描述
文件： dojo / dir1 / utils / XmlJsonUtils.js
// Author: Rajat Khandelwal
define([
"dojo/_base/declare" // declare
], function(declare){
return declare("dir1.utils.XmlJsonUtils",[],{
parseXml : function (xml) {
var self=this;
var dom = null;
if (window.DOMParser) {
try {
dom = (new DOMParser()).parseFromString(xml, "text/xml");
}
catch (e) { dom = null; }
}
else if (window.ActiveXObject) {
try {
dom = new ActiveXObject('Microsoft.XMLDOM');
dom.async = false;
if (!dom.loadXML(xml)) // parse error ..
window.alert(dom.parseError.reason + dom.parseError.srcText);
}
catch (e) { dom = null; }
}
else
alert("cannot parse xml string!");
return dom;
},
xml2json : function (xmldata)
{
var self=this;
if(xmldata.firstChild==null)
{
return {name:xmldata.nodeName+": (value null)", checked: true}
}
else if(xmldata.firstChild.nodeType==3)
{
return {name:xmldata.nodeName+": "+xmldata.firstChild.nodeValue, checked:true}
}
else
{
var mychildren=[];
var i=0;
var nochildren=xmldata.childElementCount
for(i=0;i<nochildren;i++)
{
var j=self.xml2json(xmldata.childNodes[i])
mychildren[i]=j
}
var ret= {name:xmldata.nodeName, children:mychildren, checked:true}
return ret
}
},
convert2arr : function (result,ctr,res_arr)
{
var self=this;
if(result[ctr].checked[0]==false)
return;
if(result[ctr].children==undefined)
{
var name=result[ctr]['name'][0];
var kv = name.split(': ');
if(kv[1]=="(value null)")
kv[1]="";
res_arr.push.apply(res_arr,["<",kv[0],">",kv[1],"</",kv[0],">"]);
return ctr+1;
}
else
{
var i=ctr;
var new_ctr=ctr;
var no_children=result[ctr].children.length;
res_arr.push.apply(res_arr,["<",result[ctr].name[0],">"])
for(i=0;i<no_children;i++)
{
new_ctr=self.convert2arr(result,result[ctr].children[i]._0,res_arr)
}
res_arr.push.apply(res_arr,["</",result[ctr].name[0],">"]);
return new_ctr;
}
},
convert2xml : function (result)
{
var arr=[]
self.convert2arr(result, 0, arr)
return arr.join('')
}
})
})
，但是在代码中需要 dir1.utils.XmlJsonUtils 时， code>未捕获错误：声明XmlJsonUtils：基类不是可调用构造函数。声明某些效用函数的正确方法是什么？
but when in the code I require the dir1.utils.XmlJsonUtils, it says Uncaught Error: declare XmlJsonUtils: base class is not a callable constructor. What is the correct way to declare some utility functions.
那些应该是静态函数。我不想做 x = new XmlJsonUtils（）; x.parseXml（..）。我想做 XmlJsonUtils.parseXml（..）
And those should be like static functions. I don't want to do x=new XmlJsonUtils(); x.parseXml(..). I want to do XmlJsonUtils.parseXml(..)
推荐答案
你的类不应该有定义的构造方法，dojo.declare应该处理这个..但是，这样做没有伤害，只需定义一个空白的构造函数：function（）{} 。我怀疑你面临某种错误。
Your class should not have to have the constructor method defined, dojo.declare is supposed to handle this.. However, doing so doesnt hurt, simply define a blank constructor: function() { }. I suspect youre facing some sort of bug.
定义是应该的，'define'用于require-scope，当运行require（[我的。模块]），它预计有一个定义方法，它通过 declare 返回基类。
The define is as should be, 'define' is used for the require-scope, when running require(["my.module"]), its expected to have a define method, which returns the base class via declare.
文件： dojo / dir1 / utils / XmlJsonUtils.js ：
define([
// requirements
"dojo/_base/declare",
"dir1/utils/Toolkit" // sample in-package dependency
"./Toolkit" // Same as Above
], function (declare) {
// no slash separator, use dot with declare,
// use a reference and return on last line
var Klass = declare(
/// declaredClass: string, moduleUrl with dot-separater + filename /.js//
"dir1.utils.XmlJsonUtils",
/// base class: Array(mixins)
[],
/// class scope
{
_methodMeantToBePrivate: function() { },
randomInstanceMethod: function() { }
}
); // end declare
// set any aliases, which you want to expose (statics)
Klass.StaticCallable = function() {
// careful with your scope access inhere
}
// return the declared class to 'define'
return Klass;
}); // end define
这样（你必须有一个引用，或者用require或getObject来插入） ，您可以使用 StaticCallable 函数，而不初始化/构建模块的实例。 AMD兼容的语法是这样的：
This way (you must have a reference, either pulled in with require or getObject), you could use the StaticCallable function without initializing / constructing an instance of the module. AMD compliant syntax is like so:
require(["dir1/utils/XmlJsonUtils"], function(xmlUtils) {
xmlUtils.StaticCallable();
});
或如果以前需要
var xmlUtils = dojo.getObject("dir1.utils.XmlJsonUtils")
xmlUtils.StaticCallable();
一个具体的例子可能是一个通用的类，如下所示，实例和静态访问都是可能的。基类定义工具，派生类定义工具操作的变量，如果实例化，可以订阅默认主题 - [ MessageBusBase | MessageBus ]
A specific example could be a versatile class like the following, where both instance and static access is possible. Base class defines 'tools', derived class defines the variables the 'tools' operate on - and if instantiated, the default topics can be subscribed - [ MessageBusBase | MessageBus ]
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