实例化和使用源之间的DOJO差异 [英] DOJO difference between instantiation and using source

问题描述

我是新来的DOJO，试图弄清这两种用法之间的区别，看似两件事情。

  dndController：new dijit.tree.dndSource（dijit.tree.dndSource，{copyOnly：true}）
  

和

  dndController：dijit.tree.dndSource
  

第二个工作，但是当我使用第一个一，加载我的树给我一个错误。它表示类型节点未定义。我想使用第一个的原因是因为我想将copyOnly设置为true。

任何答案都赞赏它。

解决方案

该参数期望一个构造函数函数，而不是您传递的对象。也许以下的工作：

  dndController：function（arg，params）{
 return new dijit.tree.dndSource （
 arg，//不要弄乱第一个参数
 dojo.mixin（{}，params，{copyOnly：true}））
 //创建参数的副本对象，但将copyOnly设置为true 
} 
  

某些说明：

我实际上不知道有关拖放在树上的任何内容。我所做的只是查看Tree源代码（它的dijit / Tree.js或类似的东西），以找出使用dndController的位置。从那时起，我可以发现，这应该是一个可以接收这两个参数的函数（或一个表示这样的函数的路径的字符串）。使用的实际dijit.tree.dndSource函数只是从你的问题语句中复制出来，希望它可以正常工作。

dojo.mixin函数将所有对象中的其第二，第三，...参数进入第一个参数。通过使用一个新的，空的对象作为接收对象，我们有一个简单的方法来制作一个浅色的params副本，在不修改原始params对象的情况下设置copyOnly。

I am new to DOJO and trying to figure out the difference between these two uses of the seemingly two things.

dndController: new dijit.tree.dndSource("dijit.tree.dndSource",{copyOnly:true})

and

dndController: "dijit.tree.dndSource"

The second one works, but when I use the first one, it gives me an error when loading my tree. It says type node is undefined. The reason I want to use the first one though is because I want to set copyOnly to true.

Any answers appreciated it.

解决方案

That parameter expects a constructor function instead of the object you passed. Perhaps the following would work:

dndController: function(arg, params){
    return new dijit.tree.dndSource(
        arg,  // don't mess up with the first parameter
        dojo.mixin({}, params, {copyOnly:true}))
           //create a copy of the params object, but set copyOnly to true
}

Some explanation:

I actually don't know anything about drag-and-drop on trees. All I did was look at the Tree source code (its at dijit/Tree.js or something like that) to find out where dndController is used. From that point I could find out that is was supposed to be a function that can receive these two parameters (or a string representing the path to such a function...). The actual dijit.tree.dndSource function that is used I just copied from your question statement, hoping it would work.

The dojo.mixin function mixes in all the objects in its 2nd, 3rd, ... arguments into the first argument. By using a new, empty, object as the "receiving" object we have a neat way to make a shallow copy of params, settting copyOnly without modifying the original params object.

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