По типу function () { var

Question

По типу function () { var

self = this
, hookArgs // arguments eventually passed to the hook - are mutable
, lastArg = arguments[arguments.length-1]
, pres = this._pres[name]
, posts = this._posts[name]
, _total = pres.length
, _current = -1
, _asyncsLeft = proto[name].numAsyncPres
, _asyncsDone = function(err) {
if (err) {
return handleError(err);
}
--_asyncsLeft || _done.apply(self, hookArgs);
}
, handleError = function(err) {
if ('function' == typeof lastArg)
return lastArg(err);
if (errorCb) return errorCb.call(self, err);
throw err;
}
, _next = function () {
if (arguments[0] instanceof Error) {
return handleError(arguments[0]);
}
var _args = Array.prototype.slice.call(arguments)
, currPre
, preArgs;
if (_args.length && !(arguments[0] == null && typeof lastArg === 'function'))
hookArgs = _args;
if (++_current < _total) {
currPre = pres[_current]
if (currPre.isAsync && currPre.length < 2)
throw new Error("Your pre must have next and done arguments -- e.g., function (next, done, ...)");
if (currPre.length < 1)
throw new Error("Your pre must have a next argument -- e.g., function (next, ...)");
preArgs = (currPre.isAsync
? [once(_next), once(_asyncsDone)]
: [once(_next)]).concat(hookArgs);
try {
return currPre.apply(self, preArgs);
} catch (error) {
_next(error);
}
} else if (!_asyncsLeft) {
return _done.apply(self, hookArgs);
}
}
, _done = function () {
var args_ = Array.prototype.slice.call(arguments)
, ret, total_, current_, next_, done_, postArgs;

if (_current === _total) {

next_ = function () {
if (arguments[0] instanceof Error) {
return handleError(arguments[0]);
}
var args_ = Array.prototype.slice.call(arguments, 1)
, currPost
, postArgs;
if (args_.length) hookArgs = args_;
if (++current_ < total_) {
currPost = posts[current_]
if (currPost.length < 1)
throw new Error("Your post must have a next argument -- e.g., function (next, ...)");
postArgs = [once(next_)].concat(hookArgs);
return currPost.apply(self, postArgs);
} else if (typeof lastArg === 'function'){
// All post handlers are done, call original callback function
return lastArg.apply(self, arguments);
}
};