backwards compatibilify your callback functions while migrating apis to promises
npm install callbackifyjs
var callbackify = require('callbackify')var getUserById = callbackify(function (id) {
// in this example, we're using minq
return db.users.byId(id).first()
})
// later in your code, we can use a callback
getUserById(23, function (err, user) {
if (err) { / give up / return }
console.log('hello, ', user.name)
})
// but for newer code, we can consume it as a promise
getUserById(23).then(function (user) {
console.log('hello, ', user.name)
}, function (err) {
console.error(err)
})
`
will also preserve the this context of your functions:
`js
getUserById.call({foo:true}, 12)
// the underlying promise-returning function is called with the supplied context argument
`Normally, callbackify will only work with fixed-parameter-length functions, and will use the declared
parameter length to determine if the extra callback argument is present. If you need to use
callbackify with variadic functions, or functions that don't declare their full argument
list, you can use:
js
// options argument is optional
var getUserById = callbackify.variadic(function (id, options) {
if (options === undefined) { options = {} }
if (options.select) {
return db.users.byId(id).select(options.select).first()
} else {
return db.users.byId(id).first()
}
})// we can do either of these
getUserById(23, function (err, user) { })
getUserById(23, { select: [ 'name' ] }, function (err, user) {} )
`
Note that this will not work if the last argument your function can take
is a function, as that last argument will always be detected as a callback
function.api
$3
Takes a Promise-returning function
$ npm install callbackify
From package root:
$ npm install
$ npm test
- jden
- tootallnate
MIT. (c) MMXIII jden