1.1.0 • Published 5 years ago
promise-mate v1.1.0
promise-mate
Promise.all
fulfillment for many Promises
to many callbacks to prevent duplicate calls when there are shared requirements.
Use cases
Use promise-mate if you have multiple Promises
to run synchronously that are required by multiple callbacks, some of which have overlapping requirements. This is particularly useful for modular callbacks that may not always be called as well as for resource fetching.
Installation
npm i promise-mate
Or,
yarn add promise-mate
Example
The below example fetches data to update the webpage.
import Mate from 'promise-mate'
const runner = new Mate({
users() {
return fetch('/api/users').then(res => res.json()).then(json => json.users)
},
purchases() {
return fetch('/api/purchases').then(res => res.json()).then(json => json.purchases)
},
products() {
return fetch('/api/products').then(res => res.json()).then(json => json.products)
},
calendar() { // Note: this Promise definition is not requested below so will not be run
return fetch('/api/calendar').then(res => res.json()).then(json => json.calendar)
}
});
runner
.all([
{
requires: 'users',
then(users) {
// Update the user list!
}
},
{
requires: ['products', 'purchases'],
then(products, purchases) {
// Update product list to show if something's been bought
}
},
{
requires: [{ uuid: 1265723 }, 'users', 'products', 'purchases'],
then(userData, users, products, purchases) {
// Show user's latest purchases
}
}
])
.then(() => { console.log('Page updated!') })
.catch(() => { console.error('Error updating page') })
API
Mate.all
Run all actions.
Mate.all(definitions, actions)
Arguments
definitions
- Key-indexed object with values that are functions that return Promises (or something else).actions
- Array of objects defining requirements and callbacks.actions[i].requires
- Requirements to be passed as arguments to the callback. Can be a singular requirement or an array of requirements. Singular requirements cannot be an array. If a requirement is not a key indefinitions
, will resolve the requirement.actions[i].then
- Function to call when requirements resolve. Passes results as arguments in order ofactions[i].requires
.
Returns
Promise<any[]>
- An array of what each action's callback returns.
new Mate
Create a Mate
with stored definitions.
var runner = new Mate(definitions)
Arguments
definitions
(optional) - Key-indexed object with values that are functions that return Promises (or something else).
Mate.prototype.define
Store a Promise generating function.
runner.define(key, definition)
Arguments
key
- Key for definition.definition
- Function that returns aPromise
(or something else sincePromise.all
will just resolve non-promises).
Returns
- The
Mate
instance.
Mate.prototype.undefine
Delete a definition
runner.undefine(key)
Arguments
key
- Key for deletion.
Returns
- The
Mate
instance.
Mate.prototype.all
Run all actions.
runner.all(actions)
Arguments
actions
- Array of objects defining requirements and callbacks.actions[i].requires
- Requirements to be passed as arguments to the callback. Can be a singular requirement or an array of requirements. Singular requirements cannot be an array. If a requirement is not a key indefinitions
, will resolve the requirement.actions[i].then
- Function to call when requirements resolve. Passes results as arguments in order ofactions[i].requires
.
Returns
Promise<any[]>
- An array of what each action's callback returns.