javascript 在 ExtJS MVC 中在哪里添加全局变量？
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Where to add Global variables in ExtJS MVC?
提问by Art F
I am wondering where to add global variables for an ExtJS Application. I already looked at some suggestions in stackoverflow that mention that you can add them inside app.js. But, can anyone be more specific? My app.js looks something like this:
我想知道在哪里为 ExtJS 应用程序添加全局变量。我已经查看了 stackoverflow 中的一些建议，其中提到您可以将它们添加到 app.js 中。但是，任何人都可以更具体吗？我的 app.js 看起来像这样：
Ext.application({
launch: function() {..}
});
So, where exactly do the variables go? In the launch function? Outside Ext.application?
那么，变量究竟去了哪里？在启动功能中？外面Ext.application？
采纳答案by Lloyd
Declare your own object namespace and add them there:
声明您自己的对象命名空间并将它们添加到那里：
Ext.ns('My.Application.Globals');
My.Application.Globals.SomeValue = 5;
My.Application.Globals.SomeText = 'Hello World!';
However globals are usually frowned upon unless absolutely needed, so try and get around using them if you can.
然而，除非绝对需要，否则全局变量通常是不受欢迎的，所以如果可以的话，尽量不要使用它们。
回答by rai.skumar
Better approach would be to create a separate class to hold such global constants. Then you should just put that constants class as requiresin app.js.
更好的方法是创建一个单独的类来保存这样的全局常量。然后你应该把这个常量类按要求放在app.js 中。
Ext.define("App.Constants", {
singleton : true,
BASE_URL : "http://localhost:8080/",
LABLE_HEADER : "geekrai.blogspot",
TIMEOUT : 6000
});
This will ensure that class is loaded and now you can access any property/global value. I have mentioned the same in detail on my blog : link
这将确保类已加载，现在您可以访问任何属性/全局值。我在我的博客上详细提到了同样的内容：链接
回答by dbrin
I know you already accepted an answer which is fine. I just wanted to add an MVC way to include namespaced variables available to the app. There is one caveat to these 'globals' - you can not use them in your class definitions. Meaning you can not reference your app in Ext.define({})methods. They have to be use in initComponentmethod or later.
我知道你已经接受了一个很好的答案。我只是想添加一种 MVC 方式来包含应用程序可用的命名空间变量。这些“全局变量”有一个警告 - 您不能在类定义中使用它们。这意味着您不能在Ext.define({})方法中引用您的应用程序。它们必须在initComponent方法中或以后使用。
So here is what I do:
所以这就是我要做的：
Ext.application({
name:'MyApp',
appFolder:'js/app',
controllers:[ 'Main' ],
autoCreateViewport : true,
launch:function () {
console.log("App Launched!");
MyApp.app = this; //added this to get reference to app instance. IMPORTANT!
},
//variables used throughout the app
globals:{
myURL:'http://example.com',
magicNum:5
}
});
To use these application wide variables you reference your app namespace and so do not pollute the global space. Like this:
要使用这些应用程序范围的变量，您需要引用您的应用程序命名空间，因此不要污染全局空间。像这样：
MyApp.app.gloabals.magicNum
回答by Adam Rackis
Aside from whatever features may be built into Ext, you can always use an immediate function to create a closure:
除了可能内置的任何功能外Ext，您始终可以使用立即函数来创建闭包：
(function(){
var globalVariable = 'foo';
Ext.application({
launch: function() { alert(globalVariable); }
});
})();
