I am having a hard time overriding a constructor from a singleton class in ExtJS 4.1. I have an override defined, but by the time my override statement gets processed, the constructor has already executed.
Ext.define('singleton', {
singleton: true,
constructor: function() {
alert('replace me');
}
});
Overriding the constructor of a singleton doesn't make sense, a singleton is a class that is very early on in the execution of Extjs turned into an instance of itself. This means that you are trying to override an instance of a class and not the class itself.
I can recommend that whatever you want done to the singleton be done in a separate method in the class definition that you can call very early in Ext.onReady() or your apps instantiation.
You can't override a singleton class, that is true, but you can override the singleton instance:
Ext.define('singleton', {
singleton: true,
constructor: function() {
// does whatever
}
});
Ext.define('singletonOverride', {
override: 'singleton',
// adding new property
foo: 'bar',
// adding new method
baz: function() {},
initSingletonOverride: function() {
// do whatever is needed
// to augment the singleton
// behavior the way you want
}
},
function() {
// `this` is the singleton instance
this.initSingletonOverride();
});
Keep in mind that all this fluff comes down to the JavaScript objects. A class is an Object, and a class instance is another Object. You can override either of them, or both; the class system is here to help you not to lose track of what you're doing.
