action-chainer
v1.0.0
Published
Chain async actions one after another. Makes it easy to do async actions when they depend on each other.
Downloads
5
Keywords
Readme
Action Chainer
Chain async actions one after another. Makes it easy to do async actions when they depend on each other.
Installation
npm install action-chainer
Example: API calls that need to pass headers from one to other
This example will take the x-value
header from the previous call, and set it for the next one:
const Chainer = require('action-chainer');
const chainer = new Chainer({
// Sets the state after a successful action
reducer: function(res) {
var state = {
headers: {
'x-value': res ? res.headers.get('x-value') : null
}
};
return state;
},
// Prepares the action arguments based on the given arguments and state
argsTransformer: function([input, init], state) {
return [input, state];
}
});
// Wraps around the fetch API
const chainableFetch = (input, init) => chain(window.fetch, [input, init], window);
Promise.all([
chainableFetch('/foo'),
chainableFetch('/bar'),
chainableFetch('/baz')
]).then((responses) => {
// Handle the responses
// Fetch calls were done one after another and the `x-value` header was passed from one to another
});
Docs
Constructor
The constructor accepts an options object that can contain two methods:
reducer(result)
The reducer method receives the action result, and should return a new state
argsTransformer(functionArgs, state)
The argsTransformer receives a list of arguments given to the chained function (as an array) and the state returned by the reducer of the previous action. It should return an array of arguments that should be passed to the original wrapped action function
chain(func, args, ctx)
The chainer instance has only one method - chain. It receives the function we want to call, an array of arguments we want to pass to it and the context we want to use (optional). Chain can be used for one time chained calls, but it can also be used to wrap functions for multiple uses (like in the example above)
License
The MIT License
Credits
action-chainer is maintained and sponsored by Infinum.