correct way to access class method in callback [prototype]
I'm using prototype 1.7 and building a class that will essentially take a list of divs and builds a tab interface.
var tabs = Class.create({
initialize: function(container, options) {
this.options = Object.extend({
// additional options
tabsRendered: null,
}, options || {});
// init code
if( this.options.tabsRendered ) {
this.options.tabsRendered();
}
},
// additional methods
setCurrent: function(link){
//adds a .current class t开发者_JAVA技巧o tab clicked and its corresponding section
}
};
new vtabs( 'products', {
tabsRendered: function(){
if( window.location.hash != "" ) {
var link = $$( 'a[href$="' + window.location.hash + '"]');
this.setCurrent(link);
}
}
});
My question relates to my tabsRendered custom callback. When the callback runs, this.setCurrent(link)
does nothing.
If I pass this into the callback, my custom callback works as expected.
if( this.options.tabsRendered ) {
this.options.tabsRendered(this);
}
My guess is that passing this into the callback is not best practice. So, how would I allow access to a method from within a callback?
Thanks
The problem is that tabsRendered
is unbound. With Prototype you'll have to bind anonymous functions using bind()
. After // init code
do:
if (Object.isFunction(this.options.tabsRendered))
this.options.tabsRendered = this.options.tabsRendered.bind(this);
After that you can call this.options.tabsRendered()
and within that once-anonymous function, this
will refer to the right object. For details on binding see the Prototype API docs.
EDIT: As commented: it's correct that anonymous functions aren't the only ones affected. It's the this
from the scope from which a function was defined.
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