source: Dev/trunk/src/client/dojox/lang/aspect/tracer.js

dojo.provide("dojox.lang.aspect.tracer");

(function(){
        var aop = dojox.lang.aspect;
        
        var Tracer = function(/*Boolean*/ grouping){
                this.method   = grouping ? "group" : "log";
                if(grouping){
                        this.after = this._after;
                }
        };
        dojo.extend(Tracer, {
                before: function(/*arguments*/){
                        var context = aop.getContext(), joinPoint = context.joinPoint,
                                args = Array.prototype.join.call(arguments, ", ");
                        console[this.method](context.instance, "=>", joinPoint.targetName + "(" + args + ")");
                },
                afterReturning: function(retVal){
                        var joinPoint = aop.getContext().joinPoint;
                        if(typeof retVal != "undefined"){
                                console.log(joinPoint.targetName + "() returns:", retVal);
                        }else{
                                console.log(joinPoint.targetName + "() returns");
                        }
                },
                afterThrowing: function(excp){
                        console.log(aop.getContext().joinPoint.targetName + "() throws:", excp);
                },
                _after: function(excp){
                        console.groupEnd();
                }
        });
        
        aop.tracer = function(/*Boolean*/ grouping){
                // summary:
                //              Returns an object, which can be used to trace calls with Firebug's console.
                //              Prints argument, a return value, or an exception.
                //
                // grouping:
                //              The flag to group output. If true, indents embedded console messages.
        
                return new Tracer(grouping);    // Object
        };
})();