async-recurse
v3.4.1
Published
Traverse JSON or JS objects and perform asynchronous actions easily
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async-recurse
try {
var targetObject = JSON.parse(someJsonStuff);
}
let iteratee = (value, callback) => {
setTimeout(() => {
console.log('done with', value)
return callback(null); // I can pass truthy to error - which would break the traversal
}, 100);
};
To use with callback:
asyncRecurse(targetObject, iteratee, options, (err) => {
if (err) throw Err;
//...
});
To use as an ES6 promise, do not pass a fourth argument:
asyncRecurse(targetObject, worker, options)
.then(...)
.catch(...);
Or most simply:
asyncRecurse(targetObject, worker)
...
Basic behavior
If called as an ES6 Promise, then the worker can itself be a Promise. Either way, the worker can always be a function with the arguments value and callback. The worker's callback can take an error argument, which if truthy, will prematurely terminate the traversal in a similar fashion to how Promise.all will break the iteration if anything fails. If you choose to define your worker as a Promise, then you can reject to get the same behavior.
Options:
| Name | Type | Default | |-----------------|---------|----------| | includeLeaves | Boolean | true | | includeBranches | Boolean | false | | parallel | Boolean | true |
If parallel is off, the work will be done serially - the next worker won't start until the previous finished. The walk is performed as a depth-first pre-order traversal and the order serialization will accord.
A branch is an Object or Array and a leaf is everything else (in other words if you're parsing from JSON a leaf must be a String, Number, Boolean, or null).
by Dillon Bostwick