nodejs 小工具之 event

使用node做一些小工具，还是很方便的。今天我就来分享下 event 小工具(有效的避免Node的事件回掉)

function Event(){
    this.__listeners__ = [];
}

Event.prototype.addEvent = function(name, callback, tag){
    if(app.Utils.isNull(name)){
        console.error("current event name must not be null");
        return;
    }

    if(!app.Utils.isFunction(callback)){
        console.error("current event callback must be an instance of function");
        return;
    }

    if(this.__listeners__[name]){
        console.error("current event already exits");
        return;
    }

    tag = tag || "";
    this.__listeners__[name] = {callback, tag};

}

Event.prototype.dispatchEvent = function(event){
    let name = event.name;
    if(app.Utils.isNull(name)){
        console.error("current event name must not be null");
        return 
    }

    let target = this.__listeners__[name];
    if(app.Utils.isNull(target)){
        console.error("current event not exits");
        return 
    }
    
    event.tag = target["tag"];
    event.data = event.data || {};
    target['callback'](event);
}

Event.prototype.removeEventByName = function(name){

    if(this.__listeners__[name]){
        this.__listeners__[name] = null;
        delete this.__listeners__[name];
    }
    
}

Event.prototype.removeEventByTag = function(tag){

    if(app.Utils.isNull(tag)){
        console.error("currcert event tag must not be null ...");
        return;
    }
    for (const name in this.__listeners__) {
        if (this.__listeners__.hasOwnProperty(name)) {
            let tagname = this.__listeners__[name]["tag"];
            if(tagname === tag){
                this.removeEventByName(name);
            }            
        }
    }
}


module.exports = Event;