jQuery插件，上下文和setTimeout [英] jQuery plugin, context and setTimeout

问题描述

我正在为jQuery编写一个插件，但由于JavaScript的上下文问题，我一头雾水.

I'm writing a plugin for jQuery and I have a mess in my head with the context issue in javascript.

这是我插件的简化版本:

This is a simplified version of my plugin:

(function($){  

$.fn.myplugin = function(options){
    return new MyPlugin(this, options);
};


function MyPlugin(el, o )
{
    this.root    = el;
    this.input_box = el.find('#the_input');
    this.map = null;
    this.timeout = null;
    var self = this;

    self.input_box.keyup( function(){
    if( self.timeout!==null )
    {
       clearTimeout( self.timeout );
    }
    self.timeout = setTimeout( function(){
            self.search_address( self );
            }, 500 );
    });
}

MyPlugin.prototype = {

    search_address : function( context ){
          geocoder.geocode({'address':$('#direction').val()}, 
             function( results, status ){
              var lat = results[0].geometry.location.lat();
              var lng = results[0].geometry.location.lng();
              var latlng = new google.maps.LatLng( lat, lng );

              context.select_address( latlng, '' );                                   
    },

    select_address : function( latlng, text ){
        self.root.find('#url').val('http://maps.google.com/?q='+encodeURI($('#direccion').val())+'&ll='+coords.lat()+','+coords.lng()+'&ie=UTF8&oe=UTF8&z=18');
    }
};
})(jQuery);

我已经读过setTimeout将上下文设置为全局对象，所以我做了闭包以将上下文传递给search_address函数.这使我可以从geocode函数的回调中调用select_address，但是此回调正在调用select_address，因此上下文再次不受欢迎:找不到self.root.

I've read that setTimeout sets the context to the global object, so I did the closure to be able to pass the context to search_address function. This allowed me to call select_address from the callback in geocode function, but this callback is calling select_address and there the context is again undesired: self.root is not found.

我完全不知道如何处理上下文，尽管我在初始化对象"时使用var self=this可以避免这些问题...

I'm completly lost at how to handle the context, I though that using the var self=this at the initialization of the "object" I would avoid these problems...

我必须注意，select_address可以直接调用...

I must note that select_address can be called directly...

推荐答案

在那时使用this来引用当前上下文:

Use this at that point to refer to the current context:

select_address : function( latlng, text ){
    this.root.find('#url').val('http://maps.google.com/?q='+encodeURI($('#direccion').val())+'&ll='+coords.lat()+','+coords.lng()+'&ie=UTF8&oe=UTF8&z=18');
}

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