【async.waterfall】
if any of the tasks pass an error to their own callback, the next function is not executed, and the main callback is immediately called with the error.
async.waterfall([ function(callback) { callback(null, ‘one‘, ‘two‘); }, function(arg1, arg2, callback) { // arg1 now equals ‘one‘ and arg2 now equals ‘two‘ callback(null, ‘three‘); }, function(arg1, callback) { // arg1 now equals ‘three‘ callback(null, ‘done‘); } ], function (err, result) { // result now equals ‘done‘ });
// Or, with named functions: async.waterfall([ myFirstFunction, mySecondFunction, myLastFunction, ], function (err, result) { // result now equals ‘done‘ }); function myFirstFunction(callback) { callback(null, ‘one‘, ‘two‘); } function mySecondFunction(arg1, arg2, callback) { // arg1 now equals ‘one‘ and arg2 now equals ‘two‘ callback(null, ‘three‘); } function myLastFunction(arg1, callback) { // arg1 now equals ‘three‘ callback(null, ‘done‘); }
参考：https://caolan.github.io/async/docs.html#waterfall
原文：http://www.cnblogs.com/tekkaman/p/7490846.html
