承诺：将新参数传递给链序列中的项目

Question

I'm using the q library for promises . I'm trying to chain multiple functions that return promises together in a sequence, but I want to pass new parameters in.

eg I want to do this pseudo-code:

var func1Param = 'abc';
var func2Param = 'def';
var func3Param = 'ghi';

func1(func1Param).then(func2(func2Param)).then(func3(func3Param));

So far to handle this, I've been doing something like the following, and then having the first function have all the parameters, and pass them on to the second function with the resolve, and so forth. eg

var parms = { func1 : 'abc', func2: 'def', func3: 'ghi' }
func1(params).then(func2).then(func3);

However, this seems sloppy to pass parameters to a function that doesn't need them to get those parameters to a function that does need them.

What is the best way to do this? Every option I come up with either doesn't work, or seems kind of crazy convoluted. There has to be a simple way to do this properly.

Answer 1

I'm not sure if I understand this correctly, but if you want to add default/prespecified variables to (Promise) callbacks you can use Function.bind(thisArg[, arg1[, arg2[, ...]]])

Eg

function1(foo)
    .then(function2.bind(this, bar)
    .then(function3.bind(this, baz)